E92 335i crank no start need help

[Eurofam]

Hey guys finally getting the 335i back up and running and Iv hit a snag. She cranks but does not fire up. I have mhd and will post codes. Parts replaced are as follows: sparkplugs, coilpacks, crankshaft position sensor, both camshaft position sensors, both vanos solenoids, and the lpfp in the tank. I’ve sprayed starting fluid in the intake and she fires right up but dies immediately after leading me to a fueling issue but with no codes related to the fuel pump or injectors.
Dme codes are as follows:

- DME active codes -
2ACC - DME: DME master relay, shift delay.
2CFB - DME: Throttle-valve adaptation value.
2D09 - DME: THROTTLE.
2E8E - BSD, message; intelligent battery sensor (IBS): Missing.
2F0D - DME: Radiator blind, activation, (GLF).
CDAD - Message error (request, wheel torque, drive train, 0xBF), DME receiver, DSC / LDM transmitter.

[Eurofam]

I might add I don’t hear the lpfp in the tank prime when the car is turned on, even being brand new. Could it be the dme main relay causing everything? Where exactly is it I found a blue relay in the ebox under the hood that I found in other threads to be the relay I’m looking for but other answers are mixed

[bms5]

I might add I don’t hear the lpfp in the tank prime when the car is turned on, even being brand new. Could it be the dme main relay causing everything? Where exactly is it I found a blue relay in the ebox under the hood that I found in other threads to be the relay I’m looking for but other answers are mixed

Depending on production date, the location varies.
For 03/2007 onwards, this is what is shown.

https://www.newtis.info/tisv2/a/en/e92-335i-cou/components-connectors/components/k-relays/k6300-dme-relay/IROpqxeg


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[Eurofam]

So I replaced the k6300 relay and still no start and the code came right back, i Pulled the throttle body and it’s not responsive when turning power on, also still didn’t start with the throttle body off. I did remove a line to injector 1 and confirmed fuel is flowing so I’m lost on this one? What would cause a no start condition with these codes

[talon1pilot]

So I replaced the k6300 relay and still no start and the code came right back, i Pulled the throttle body and it’s not responsive when turning power on, also still didn’t start with the throttle body off. I did remove a line to injector 1 and confirmed fuel is flowing so I’m lost on this one? What would cause a no start condition with these codes

Same here, completed extensive troubleshooting with no answers. Replaced Junction (Fuse) Box, still getting 2ACC (DME Main Relay Delay) and crank but no start. Did you get it running or find any answers? Thanks, ready to help each other!

-Andrew

[Sam3025]

Hey guys finally getting the 335i back up and running and Iv hit a snag. She cranks but does not fire up. I have mhd and will post codes. Parts replaced are as follows: sparkplugs, coilpacks, crankshaft position sensor, both camshaft position sensors, both vanos solenoids, and the lpfp in the tank. I’ve sprayed starting fluid in the intake and she fires right up but dies immediately after leading me to a fueling issue but with no codes related to the fuel pump or injectors.
Dme codes are as follows:

- DME active codes -
2ACC - DME: DME master relay, shift delay.
2CFB - DME: Throttle-valve adaptation value.
2D09 - DME: THROTTLE.
2E8E - BSD, message; intelligent battery sensor (IBS): Missing.
2F0D - DME: Radiator blind, activation, (GLF).
CDAD - Message error (request, wheel torque, drive train, 0xBF), DME receiver, DSC / LDM transmitter.

Hi
I’m getting exactly the same issue with my 325i 2009 !
Can you please tell me if you’ve managed to repair yours and how?
Thank you

[drewusmaximus]

Are you able to get another DME and swap out the original, then see what happens? Seems like the DME is having a hard time communicating with the car. I say that because of the 2E8E code. If the IBS were missing, you wouldn't even get a crank. Hopefully you're able to find/borrow a DME and test. Good luck and keep us updated..

[E90bill]

So did you guys ever get it figured out. I to have an 06 325xi and I’m in the same boat. I actually have replaced every single thing that the OP has too. Along with almost all the same codes. Cars been down over a month. I’m at a loss…..

[Mr.BimmerOnly]

535i same exact problem. Does anyone have a remedy!??!!!! I’m desperate!!

[Alphaexray]

I don't know if he ever solved this problem. I assume he did, but if you have the "exact" same codes, I'd start with the IBS. That signals power continuity problems to the DME, probably from bad damaged or loose connections along the main power supply. Super common. Then check the grounds, both engine, and the secondaries. If that's all good, then you start troubleshooting the DME. When you have a sudden appearance of codes in various systems, the likelihood of all of those systems failing at once is very low. If the DME is failing then you'll start getting multiple systems failing. Check the condition of the DME housing, the pins and wires connecting it, and see if you have errors in communication with it. My guess is this is intermittent main power feed.

[drewusmaximus]

Sounds like a short circuit counter has been reached. I believe BMW sets a counter limit on electrical parts to avoid failure. The DME will cut power to a device once the device reaches a short circuit counter of 50. Can occur due to low voltage or voltage spikes or that part(s) receiving intermittent power. Sounds like with all the testing, the part(s) might have reached the counter limit. You can verify the counter limit on the part(s) using Tools32. The tough part will be resetting the counters for every part that is not getting power, i.e., FRM. I was relearning my VVT motor this weekend and with plugging and unplugging my laptop and OBD reader, clearing codes, starting the car, turning off the car, ignition and the battery slowly draining, my FRM module reached the counter limit, which means there's no power to the FRM module, in which controls my headlights, signals, windows, reverse lights and internal lights. Right now, I'm driving with daytime running lights and brake lights. Tomorrow, I will use Tools32 to clear all the counters on each part, which will re-enable my FRM. Another safety feature of BMW. I guess fuses aren't good enough, so BMW took it a step further.

[Alphaexray]

Hey Drew, did you check to see if your FRM is covered under the recall. BMW just swapped out the one I had on this 2011 e90 I was working on no charge.

[drewusmaximus]

Hey Drew, did you check to see if your FRM is covered under the recall. BMW just swapped out the one I had on this 2011 e90 I was working on no charge.

All I see for recalls on my car is the PCV heater. It's too bad the FRM isn't covered under the SULEV warranty. I'm going to reset the counters back to 0 tomorrow morning. I don't think the module is faulty. I believe plugging and unplugging the computer to relearn the VVT and the OBD reader to clear codes, turning on and off the ignition while the battery slowly draining, sped up the counter, thus all the lights, signals and windows don't work, except for the daytime running lights and brake lights.
I bought a new VVT motor and it did not line up with the bolt holes!! I finagled the motor in, but since it wasn't flushed, the gasket was allowing air in, thus the lean codes. I put the original back and the car suddenly behaved. I can tell the motor is on its way out, but I have a BMW guy in town who has a couple of e90s and he's going to source me a used VVT motor. Hopefully I'm successful tomorrow with the circuit counter reset.

[Alphaexray]

Good luck. Have you tried adjusting the underside bracket that holds the back bolt on the vanos. There are a few millimeters of play there. Also, check the gasket orientation. If it is upside down it won't line up with the bolts. I hope the short code removal works with tools32. I was having the same problem, checked the light ballasts etc to see if there was a short, lost the headlight and sunroof control, so I talked to my parts guy at BMW and he told me about the recall. They swapped it out no charge. I was lucky because they aren't cheap used, and chances of it being broken are still pretty high.

[drewusmaximus]

Good luck. Have you tried adjusting the underside bracket that holds the back bolt on the vanos. There are a few millimeters of play there. Also, check the gasket orientation. If it is upside down it won't line up with the bolts. I hope the short code removal works with tools32. I was having the same problem, checked the light ballasts etc to see if there was a short, lost the headlight and sunroof control, so I talked to my parts guy at BMW and he told me about the recall. They swapped it out no charge. I was lucky because they aren't cheap used, and chances of it being broken are still pretty high.

What year is your car? I contacted the dealership to inquire about a thermostat leak, since it covered under the SULEV warranty and they told me there are two recalls. The PVC heater and the VANOS bolts, which they said there is no solution for the VANOS bolts at this time. They didn't mention the FRM. I tried to reset the counter, but the FRM is not getting power, which tells me the eeprom got corrupted. I have two options; get my current FRM reprogrammed or buy used and I program it to the car. And my VVT motor is on its last leg, so I'm still dealing with that.

[Alphaexray]

The car I had fixed was a 2011 e90. I got the dealer to print up a pdf of all the service history and the recalls. It's not a sulev, just an e90 323i which is a 328 with a 2.5 engine, but really the only difference with the sulev was the fuel pump regulator and some programming, so I don't see why yours wouldn't be covered. It had the vanos bolts changed under recall, in the first few years, and now the FRM. I'd try another dealer if your guy is being that nasty about it. Honestly, my dealer was happy to do the recall because they had the unit in stock collecting dust. They also changed the blower motor wiring which they said was also on recall even though it was working fine. BTW, I spoke to a few BMW mechanics I know, and mentioned all the Vanos travel problems I had to deal with. They all said that it's usually the MAF which solved my problem, but they have seen a few cars do that when the water temperature sender fails. Apparently, they tend to fail in a hot condition, meaning they show high engine heat, and the computer algorithm tells the vanos to open fully at start. No codes until they display overheating, but they leave people stuck unable to start their cars. You might want to check that out if the new VVT motor doesn't solve your problem.

[drewusmaximus]

The car I had fixed was a 2011 e90. I got the dealer to print up a pdf of all the service history and the recalls. It's not a sulev, just an e90 323i which is a 328 with a 2.5 engine, but really the only difference with the sulev was the fuel pump regulator and some programming, so I don't see why yours wouldn't be covered. It had the vanos bolts changed under recall, in the first few years, and now the FRM. I'd try another dealer if your guy is being that nasty about it. Honestly, my dealer was happy to do the recall because they had the unit in stock collecting dust. They also changed the blower motor wiring which they said was also on recall even though it was working fine. BTW, I spoke to a few BMW mechanics I know, and mentioned all the Vanos travel problems I had to deal with. They all said that it's usually the MAF which solved my problem, but they have seen a few cars do that when the water temperature sender fails. Apparently, they tend to fail in a hot condition, meaning they show high engine heat, and the computer algorithm tells the vanos to open fully at start. No codes until they display overheating, but they leave people stuck unable to start their cars. You might want to check that out if the new VVT motor doesn't solve your problem.

I realized the VVT motor was slowly failing because I recall while driving I would hear a rattle during shifts. At first I thought it was the transmission, but after trying to relearn the motor, i heard the same exact sound. Now I can hear it more frequent. I called two dealerships near me and they only mentioned the PCV heater and VANOS bolts, but according to research, BMW revised the bolts. That tells me the dealership doesn't want to do the job. I'll do it myself because it's obvious the dealership doesn't want to do it and if they are forced, I can only imagine what they will do to try to make money, hence I do my own work. But, I found a indy shop that is going to reprogram my FRM. They want 239.00! Since the eeprom is corrupt and I don't have X-Prog, I have no choice, but I WILL be buying X-Prog for future repairs.

[Alphaexray]

Drew that's a lot for reprogram, especially if the unit has failed. You might be beating a dead horse on that one. They must have a scrap yard in your neck of the woods here you can pick up a footwell module for under a hundred bucks. I find ebay expensive, but you can still find them for under $150. They match up pretty easilly if you use ISTA-P, or ESS to match them to the car. I still use ESS on the e90's because it is fast and force of habit.

[drewusmaximus]

Drew that's a lot for reprogram, especially if the unit has failed. You might be beating a dead horse on that one. They must have a scrap yard in your neck of the woods here you can pick up a footwell module for under a hundred bucks. I find ebay expensive, but you can still find them for under $150. They match up pretty easilly if you use ISTA-P, or ESS to match them to the car. I still use ESS on the e90's because it is fast and force of habit.

I got the module fixed. The eeprom got corrupted from a slow battery drain. Get ready.... Cost me 240.00 for a 5 minute job. All works now. I still need a new VVT motor. The one I bought from Amazon didn't line up correctly, thus air getting in at the gasket. I know I know.. Don't buy China parts.. I was in a pinch art it got here the next day. Damn Amazon.. Make it easy to buy junk parts. I ordered X-Prog v5.5 for 50 bucks and the Indy shop was very nice and helpful. They told me exactly what to do if the eeprom corrupts again and was willing to disable my TPMS so the wheel sensors do the work.. This time I bought a trickle charger. Learned from my mistakes, but I also want to help locals if they're ever in a position I was. 240.00 is highway robbery for a 5 minute job. I'd charge 50 bucks to help a fellow enthusiast. It's a crappy feeling to drive around with no signals, headlights, interior lights and no windows. I'm not 25 years old anymore, so I care about safety and my insurance going up.

[Alphaexray]

People charge too much for programming, but I think it's because most people are just afraid to try it themselves. Smart move getting set up to do it yourself. I've saved a lot of money by just buying the right gear and doing it myself. The biggest rip off is key programming. Lots of shops farm out their programming, so I'm sure that will pay off for you. As for the VVT, if you still have the part, try flipping that gasket over. It's asymmetrical.

[drewusmaximus]

The line on the gasket is at the top. With the original motor on, no more leaks, but the motor is on its last leg. I was looking for a used OEM one locally, but didn't get a response.

[Alphaexray]

There are a couple of cheap ones on fleebay, around 50$. It's too bad I sold the ones I had in my surplus, I would have sent it to you. I was at the junk yard today, and it was slim pickings. I did manage to grab a bunch of wire clips and passenger side seat bottom from a 2011 for 10 bucks, so it wasn't a wasted trip. People raid the BMW's as soon as they show up. Seems like the 2011 e90's all have a leather cracking problem, so I never pass up a clean passenger base. People pay 200$ for them, and they are interchangeable.

[drewusmaximus]

There are a couple of cheap ones on fleebay, around 50$. It's too bad I sold the ones I had in my surplus, I would have sent it to you. I was at the junk yard today, and it was slim pickings. I did manage to grab a bunch of wire clips and passenger side seat bottom from a 2011 for 10 bucks, so it wasn't a wasted trip. People raid the BMW's as soon as they show up. Seems like the 2011 e90's all have a leather cracking problem, so I never pass up a clean passenger base. People pay 200$ for them, and they are interchangeable.

I found one on Besos' site for 50 bucks. Exact same as the OEM. Fits like a glove. The previous one I bought from Besos' site was High silver in color and even the connector wouldn't click in, needless to say the bolts holes didn't align, although it said it fit my 11 328xi auto. Still have a stumbling idle, but I'm going to select Run valvetronic in INSTA instead of just selecting the relearn option. Running valvetronic will go through cycles to adjust the idle.
Sorry Euro for hijacking.

[Alphaexray]

It might have carbonned up with all the wacky VVT positions. Take the car out and give it a good run, and see if it is still stumbling after that.

[drewusmaximus]

It might have carbonned up with all the wacky VVT positions. Take the car out and give it a good run, and see if it is still stumbling after that.

I think the motor is ok. I still get a stumbling idle. I noticed the oil filter housing cap was seeping oil, so I ordered another one and replaced it. Then I checked the VVT motor bolts and made sure they were snugged, but I think there's oil leaking from the oil filler cap. I pulled coil 3 to clean up the oil surrounding the coil. I threw on a trickle charger to relearn the VVT motor. After that, I started the car, but I now hear a chirp when starting up. It goes away. It only happens when the car initially starts. I had that happen before and when I readjusted the VVT motor gasket, the chirping stopped. Now I get a P00BC code, which basically means there's air getting in after the MAF.
The car was fine earlier today, with the exception of the stumbling idle. The only thing I changed was the oil filter housing cap. I put the original cap back and still get the chirp. I didn't move the vvt motor. All I did was made sure the bolts were snugged. So I'm wondering if it's the oil filler cap is the culprit. I think I need to adjust the idle in INSTA, but now I feel I need to replace the filler cap or the cap gasket.

[Alphaexray]

I doesn't sound too serious. Never hurts to fix oil leaks. When was the last time you had the intake off? If you have a smoker you can check for leaks, otherwise there are only a few places post maf for the air to get in. Map, throttle body, both DISAs, and the main intake to head seals. Usually it is the intake to head o-ring seals that dry out. They really aren't that hard to change. You don't even have to completely remove the intake. Just slide it back far enough to use an o-ring pick to pull out the old ones and pop the new ones in. 10-15 minutes tops if you already have the area exposed for the work you are doing.

[drewusmaximus]

I doesn't sound too serious. Never hurts to fix oil leaks. When was the last time you had the intake off? If you have a smoker you can check for leaks, otherwise there are only a few places post maf for the air to get in. Map, throttle body, both DISAs, and the main intake to head seals. Usually it is the intake to head o-ring seals that dry out. They really aren't that hard to change. You don't even have to completely remove the intake. Just slide it back far enough to use an o-ring pick to pull out the old ones and pop the new ones in. 10-15 minutes tops if you already have the area exposed for the work you are doing.

The thing is, I haven't touched anything else. I did replace the M6 bolts to fasten the VVT motor, but didn't have an issue the day the bolts were replaced, except for the stumbling idle. I cleaned the MAF last night and when I started the car this morning, no chirp, but still have the stumbling idle. I'm going to adjust the idle in INSTA later. I can't get confirmation on the default idle speed for the N51. I'm not sure if it's 700 or 650RPMs. If adjusting the idle doesn't work, then I'll replace the VVT gasket with a new one and see if that fixed the idle or put back the original M6 bolts.

[drewusmaximus]

Alpha, I think I resolved my issue. First, I decided to manually turn the VVT motor counter clockwise until tension. Then I replaced the oil filler cap with a new one. Finally, I went in the car and turned on ignition several times before starting. Started the car for a minute or two since it was late and went in for the night. This morning had frost on the car (NY of course) and started up the car to warm it up. No stumbling idle anymore. Car didn't shut off while idling. Drove to work and no more issues. Idle was perfect at the red lights. I'm not sure if it was adjusting the VVT motor or the oil filler cap that solved it, but I've manually turned the VVT motor prior, which didn't resolve the issue. It's safe to say the oil filler cap resolved it. I'd never thought the cap would cause such a mess.
Thanks for all of your help... Onto the next..

[Alphaexray]

Good news. Happy it worked out.

[drewusmaximus]

Good news. Happy it worked out.
Well....... This morning I dropped the kids off to school, put it in park and the idle dipped. So, I shut off the car while we waited, but now the yellow battery light came on right after shutting off the car. And the ride to school is about 15-20 minutes. The battery in the car is red and white. I assume that's the original battery, which would be 12 years old.

[drewusmaximus]

Well again... I finally figured out the vacuum leak. It's the new VVT motor gasket. I readjusted the intake boot, sprayed brake cleaner on the intake boot seams, DISA valve mating surface, the VVT motor gasket and I decided to spray the motor mating surface with brake cleaner and I can hear the cleaner being sucked in and the engine leveled out for a couple seconds. A brand new gasket failed. I noticed before installing the VVT motor, I pushed the inside mating surface of the gasket and it was quite flexible. I also saw the rubber seams to that mating surface a hair wet prior to installing the motor. I cleaned it up and it was oil, but didn't think anything of it because of the constant uninstalling and installing. Whatever they used to mount the inner metal gasket to the outer gasket seemed cheaply designed. Damn Besos!!! I found a Victor Reinz one with the gold metal inner gasket, whereas the one I recently bought was silver. At least I found the culprit.

[Alphaexray]

12 year old battery is impressive. I'm glad you found the leak. Air getting into the valve cover messes up the crankcase ventilation pressure, so that would explain the stumbling. Those gaskets are notoriously bad. I always smear a thin layer of RTV on the lip where the rubber meets the metal. I started doing that after scavenging for VVT motors from the scrap yards. They all had bad gaskets, and they were always unglued in the same place. It's not a great design, and when it comes to oil seals, BMW never seems to get them right. I'm not knocking the cars, I love the way they are built, but It's hard to find one without some kind of leak.

[drewusmaximus]

12 year old battery is impressive. I'm glad you found the leak. Air getting into the valve cover messes up the crankcase ventilation pressure, so that would explain the stumbling. Those gaskets are notoriously bad. I always smear a thin layer of RTV on the lip where the rubber meets the metal. I started doing that after scavenging for VVT motors from the scrap yards. They all had bad gaskets, and they were always unglued in the same place. It's not a great design, and when it comes to oil seals, BMW never seems to get them right. I'm not knocking the cars, I love the way they are built, but It's hard to find one without some kind of leak.

So, after further investigating, the gasket had no tares, splits or anything. I did noticed the thin layer of whatever they used around the bolt holes worn off from removing the motor. In addition, I used new m6x1.0 bolts with a round head with an Allen socket hole to fasten the motor. I have a feeling the bolts were the culprit, along with the worn rubber or whatever they used surrounding the bolt hole. i wasn't sure to use RTV after reading online not to, but I have high temp red RTV and I decided to do exactly what you did, since the RTV is between the metal gasket and the motor, not between the gasket and the VC. I also put back the original M6 bolts. I'll find out the results tomorrow, since I have to let the RTV cure.

[drewusmaximus]

So....., I finally fixed the idle issue. No more P0171 and P0174. I bought a new VVT gasket with the brass/gold backing in oppose to the silver backing. No more vacuum leak. I compared the two gaskets and there was a difference. Honestly, the silver gasket looked like the silver gasket that goes on an N52 with the aluminum VC. I believe the seller took the n52 gasket and mended it with the N51 outer gasket because the black seal they threw on the silver gasket to connect it to the outer gasket that also trails around the bolt holes fell apart when I removed the VVT motor. I can clearly see that backing belonged to an N52, whereas the new gasket looked exactly like the original and it said Reinz on it. I was about to buy an MAF, assuming the MAF went bad because according to what I researched, when you unplug the MAF and the idle smooths out, the MAF is bad. Well, not in my case. My idle smoothed out when I unplugged the MAF, yet after replacing the VVT gasket the idle smoothed out with the MAF plugged in. Drove the car, no issues and I can feel the power again. Thankfully the gasket came in before I purchased the MAF.
My uncle always told me, you buy cheap.., you get cheap.... Case closed.. Onto the next...

[Alphaexray]

It's tough to know what is and isn't good quality. I know what you mean about cheap. Nothing more frustrating than waiting for new parts to arrive and they show up so cheap you'd have been better off just leaving the old ones on. Or they don't fit right, or they are missing a crucial piece of plastic to clip together. I try to go with OE or OEM but that isn't always reasonable with BMW. Anyway, glad you got it fixed. Could you tell me what brand of gasket you ended up buying, I'd really like to add it to my list.

As for the MAF, the last one I changed had an inlet air temperature preheat code show up. I've heard of some people getting no codes and they just sort out, but I can't say that I've seen that. I have heard that they are a replace often part, so now that I am working on more of these e90's, I've picked up a cheap spare that I keep in the shop, so I can quickly rule out MAF failure.

[drewusmaximus]

It's tough to know what is and isn't good quality. I know what you mean about cheap. Nothing more frustrating than waiting for new parts to arrive and they show up so cheap you'd have been better off just leaving the old ones on. Or they don't fit right, or they are missing a crucial piece of plastic to clip together. I try to go with OE or OEM but that isn't always reasonable with BMW. Anyway, glad you got it fixed. Could you tell me what brand of gasket you ended up buying, I'd really like to add it to my list.

As for the MAF, the last one I changed had an inlet air temperature preheat code show up. I've heard of some people getting no codes and they just sort out, but I can't say that I've seen that. I have heard that they are a replace often part, so now that I am working on more of these e90's, I've picked up a cheap spare that I keep in the shop, so I can quickly rule out MAF failure.

My intention is to have spares in the garage. I keep at least two spare coils in the trunk, since they tend to fail. I got the Victor Reinz gasket. 20 bucks. The bad gasket came in a bundle with the ESSG, OFHG and VCG combined. I replaced the OFHG, which I don't think I had to. I can tell the VCG and OFHG were previously replaced. The OFHG was still pliable when I removed it. Next task is to replace the thermostat. It's starting to leak, but I'm waiting for the coolant hoses' O-rings to come in first. I know if I remove the two hoses that clip onto the thermostat, the O-ring seal is broken, thus rings should not be reused. It will be an exciting job, living upstate NY at this time of the year.. LOL

[Alphaexray]

Yeah, I'm in Canada, so never fun working outside. Thanks for the lead on the Victor Reinz gasket. Good luck on your Thermostat. If you have an automatic, you might want to change the o-ring on the coolant hose from the transmission cooler to the radiator. It's right above the drain plug. I've seen a few of those leaking now. I also have been replacing the plastic drain plugs with the brass one $5 buck at rock auto. If the rad is older, I also change the o-rings on the drain plug tube, and epoxy them back in while I have the rad dry. It's a silly piece with two tiny ears holding it in place. I also do the metal upgrade for the hose at the head. The last two I changed were broken right at the o-ring. I think the vibration cracks them. Here's a picture of the filler tube I found online.https://www.bimmerfest.com/attachments/cimg4815-jpg.262738/https://www.rockauto.com/info/107/17117530902PRM.jpghttps://www.rockauto.com/info/42/926-905-007.jpg

[drewusmaximus]

The first thing I did when I got the car was replace the coolant flange with an aluminum one. Unfortunately the O-ring that came with the aluminum coolant flange was garbage. Flattened and failed in three months. I replaced the flange with a black aluminum one and it's been good since. I just ordered a coolant hose O-ring set for my model. The set replaces all the O-rings for all coolant hoses. I know there are two hoses that connect to the thermostat that have the O-ring design and not knowing if the hoses were ever replaced, those O-rings are basically a one time use. So, as soon as I pop off those hoses, the o-rings are no bueno. So, I drove the car to work this morning for the first time after replacing the VVT gasket. It seems to drive good, but I noticed when I stop the idle dips to almost 500, but no loping idle, no check engine light, nothing. It just sinks a bit to 500 then back to 600ish only in idle while in drive position. When I'm at a light waiting for it to turn green, I watched the idle and it sits between 500-600. When in park and idle, the idle holds strong at 600ish. I'll plug in my OBD reader and watch the MAF live data. I have a 2011 328xi auto sedan w/ 117k.
I haven't had the chance to purchase the metal bleeder screw and the blue drain plug on the radiator. I was going to replace the OFH cap with a metal one, but after doing some research, I decided to stay with plastic. The original cap was sweating, as well as the oil filler cap, so I replaced both and no more leaks. I'm debating if I should replace all o-rings while the coolant is out. They say, if it ain't broke, don't fix it. Whoever made up that saying wasn't thinking proactively. LOL
I don't know if my idle is normal because I never paid attention to the idle prior. I feel as if it's not normal. Everything is sealed, I have power, no loping idle, not shutting off at idle. The dip in idle is not even physically noticeable. I know the idle dips when shifting through gears, but maybe I'm overreacting, but I feel as I'm not.

[Alphaexray]

Trust your instincts, it could be nothing, or you might have some excessive load. You mentioned your battery was older, so the alternator could be overcompensating. I use my standard obd scanner to get live data while driving. You can check the amperage draw, o2 data, just the basics. It's less distracting than using a laptop.

I agree with you on the metal flange o-ring. I notice a lot of the aftermarket parts come with the wrong gauge O-rings. IF they are too thin they get no support from the sidewalls of the groove in the part, and just flatten out and leak. As for the, if it ain't broke don't fix it, I'm normally on board with that, but these cooling systems are not like american ones, even though lots of the parts are made in America. American systems corrode in ways that seal themselves. These bimmer systems are made to come apart, and when you start shiting pieces and bleeding systems the next thing you know you have leaks where you never expected, so that's why it's best to just go nuts and refresh the system. I actually pull the fan completely, and remove the thermostat from the front, with all three hoses still connected. Then I make the swap of the hoses on the bench. Gives me a chance to inspect everything, and the lower screw holding the oil cooler to the fan assembly is usually rusted so I swap it out. Like I said before, if the rad is older, I pull the drain screw, then use a wrench on the plastic filler tube it plugs in to. I pull out that tube, change teh o-rings, and put some JB weld on the two ears that hold it in place, and shove it back in. Then I undo the rad flange just above for the automatic transmission cooler and change that o-ring. It's really common to see e-90s drip on the driver side. I always tell people if they have a left side leak, to pull the driver side wheel, and remove the front part of the inner wheel well. It's a couple of 8 mm sheet metal screws, and one 10 mm nut. With it off, you get a great view of the left side of the rad, and you can easily see where it leaks. So many people have swapped out their rads because of this problem.

[drewusmaximus]

I noticed with the aftermarket flange, the side walls are too wide, providing ample space for the o-ring to flatten.
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I like to be proactive. For example, If I'm replacing the thermostat, which means the coolant will be drained, I might as well replace all coolant O-rings and water pump in one job. I want to replace the OEM radiator with an aluminum aftermarket, but I couldn't find one that works with the SULEV model, meaning the aluminum radiator doesn't have the mount holes for the EAC sensor and I will not cob job the sensor.

So.., I drove home for lunch and watched the MAF readings with my scanner via live data. At idle the reading is at 0.5-0.6 and while I'm driving at 60mph/2,000rpms, the reading shows 3.2 -4.5. I think that's very low. I can't find a definitive answer on a normal MAF reading for the E90, but based on what I've read, the MAF reading during idle should be between 3-4 and while driving, 13-15. Either the MAF is failing and reading below average or there's a slight vacuum leak, where the engine is not sucking in the air it supposed to get from pre-MAF and the MAF is reading the amount of air difference the engine sucks after the leak, if that makes any sense. LOL Or... the battery is on it's last leg and not providing the correct voltage to the MAF. I'm going to test the battery when I get home. I didn't have a 9v battery for the multimeter, but I got one from work this morning.

[drewusmaximus]

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I think I know where the unmetered air is going in at. Of course the aftermarket intake boot doesn’t perfectly fit because of the upper slit. I think I might shave that slit down so the boot fits flush.

[Alphaexray]

That boot is a pain. I made the mistake of using dry silicone which a lot of mechanics do on the lip to assemble them faster, and all it did was make it easier to slip off. I just use a little water now, and fight with it. .5 to .6 g/s is pretty low. Usually under 2 you should be generating a code. Hopefully it's just the leak in the system you found, but that would be a pretty big leak. You might want to consider swapping the MAF. I think I paid 30 bucks for the last one I bought. I always keep a spare handy.

[drewusmaximus]

After driving home I tested the battery from the jump posts under the hood and it read between 12.5-14v. I’m going to check again since the car sat overnight. I have a Nexpeak nc201 that I try to use on the car while diagnosing via INSTA. The tender has the AGM option, which I used when diagnosing, but the yellow battery symbol turned on after I was done diagnosing. I was surprised because I used the Nexpeak as a trickle charger to keep the battery full. So, I’m wondering if the battery is the culprit and not the MAF. The readings are too low in my opinion, yet the car drives great and no check engine light which is even more surprising, based on those low levels. I have another MAF coming in today. I do want to check the voltage level at the MAF but I don’t know what the baseline voltage is for the MAF. It’s difficult to find default readings on the net.

[Alphaexray]

If I'm not mistaken, ista should display the target voltage in the MAF diagnostic sequence. I'm not really sure there is a way to access those references. When I am unable to access the diagnostic chain, I unplug whatever the unit is in question, and run the engine long enough to trip the code. Then I plug it back in, and check ISTA, and under the module code, it gives me the diagnostic voltages, and what i should be seeing during testing.

[drewusmaximus]

I did a little research and my reader reads the MAF by lb/min and from what I read, 0.5 lb/min is normal. I was reading 720717720718
it wrong. I was reading lb/hr. My idle is stable. I also cleaned the solenoids which were quite dirty. Next are the vanos non check valves. I have a MAF arriving today. I’ll swap and see if the readings are the same as the original just to be safe.

[Alphaexray]

It's supposed to be about 4-6 grams per sec, so 60s x 4g = 240g/min or 0.52lbs/min so you are pretty much golden. Maybe a little on the low end. That's probably why you aren't getting a MAF code.

[drewusmaximus]

The new MAF came in and it reads 0.58. So I think I’m good to go. I haven’t had a code so be I replaced the VVT gasket. I think I was being paranoid with the idle which is why I bought another MAF sensor to confirm the readings. I was reading the readings wrong the entire time. It’s safe to say my problem is resolved. I appreciate your wisdom. Onto the next, which is the thermostat, since the o-rings came in today.