91 850i 6spd "light" refresh

[rjjablo]

When I just did my valve stem seals and put mine back together one of my valve cover gaskets slipped during assembly on the bottom middle. They also like to not line up in the back. Break out the mirror on a stick and look. or just stick your hand down there.

Has to come back apart to fix

Did you put the dab of Reinzoil on all the seams in the head in the front and the back?

[jimmythefish]

When I just did my valve stem seals and put mine back together one of my valve cover gaskets slipped during assembly on the bottom middle. They also like to not line up in the back. Break out the mirror on a stick and look. or just stick your hand down there.

Has to come back apart to fix

Did you put the dab of Reinzoil on all the seams in the head in the front and the back?

I did run a bead along all seams on permatex black oil resistant gasket sealer. I looked this morning and one of the new rubber coolant pipes touched the valve cover gasket on the drivers side. I see some small leakage at that point onto that pipe. That coolant pipe is a bmw part that was had an “update” and one that I had to cut to fit. I did not like the fitment, but that was what they offered and I wasn’t putting the 30 year old coolant pipe back on. I am going to attempt to adjust the pipe more and see if the leak continues. I am working today, will put the car back on the lift tonight and do some more investigating.

I found a small coolant leak on the middle one of the 3 sensors on the back coolant pipe...grrrh! They are new sensors and new gaskets, I will attempt to adjust it and see if it stops weeping.

thanks rjjablo!

[jimmythefish]

Update and I hope some help:

All leaks have been solved. The oil leak was actually Pentosin from 2 banjo bolts from the power steering pump that I failed to torque down enough. The coolant leak was middle sensor back of the engine, thread sealer and retorqued and no leaky!

I am still having an issue with the car running, no faults on Bank 2 after I fixed the donut sensor issue, Bank 1 is the peake code FF C9:

Bank 1: peake code FF C9 which is a lambda sensor fault? I cleaned the MAFs with slight improvement, but still the code came back. I clean and placed a used MAF from one of my E32 750 parts car, drove the car for about 45 minutes and was noticeable better, more responsive at 2K-3K rpm with no check engine light. The car almost seemed happy. I drove the car to Phoenix the next day 2 hours 30 minutes each way, some stop and go and mainly highway 75-90 mph. The drive to Phoenix was great, no codes and seemed to be fairly normal in responsiveness.... I stopped 2 miles from my destination to get some water to drink, came back out to start the car and the car started and had a rough idle check engine light back on, code returned Peake FFC9 Bank 1, Bank 2 no codes. I noticed the lack of power between 2K-3K rpm again.

I made it to my destination and let the car sit for about 3 hours to conduct my business. I came back to start the car and same symptoms presented. I had another used cleaned MAF so I changed it and cleared the code, the car did not run well at all. I went back to the previous MAF and drove home on the highway without much difficulty and no lights, but still noticing the loss of power between 2K-3K. I made it home and at a few stop lights the car idled with no check engine light, however the code FF C9 is still present when I checked the car this morning.

Any suggestions? Would O2 sensors give me trouble like this? I have replaced everything ignition wise but o2 sensors and MAFs..... I am hopefully putting new crank position sensors on this weekend if the dealer gets the right ones. It seems the symptoms want to come and go and changing the MAF really helped but then the fault came back and so did the symptoms after a 2 hour drive.... I smoke tested the car the other week after resealing intakes and it checked out. I will smoke test it again since I have put in some driving hours.

Any help would be appreciated....this car is getting better...just needs a little more!

James

[dragon850]

Update and I hope some help:

All leaks have been solved. The oil leak was actually Pentosin from 2 banjo bolts from the power steering pump that I failed to torque down enough. The coolant leak was middle sensor back of the engine, thread sealer and retorqued and no leaky!

I am still having an issue with the car running, no faults on Bank 2 after I fixed the donut sensor issue, Bank 1 is the peake code FF C9:

Bank 1: peake code FF C9 which is a lambda sensor fault? I cleaned the MAFs with slight improvement, but still the code came back. I clean and placed a used MAF from one of my E32 750 parts car, drove the car for about 45 minutes and was noticeable better, more responsive at 2K-3K rpm with no check engine light. The car almost seemed happy. I drove the car to Phoenix the next day 2 hours 30 minutes each way, some stop and go and mainly highway 75-90 mph. The drive to Phoenix was great, no codes and seemed to be fairly normal in responsiveness.... I stopped 2 miles from my destination to get some water to drink, came back out to start the car and the car started and had a rough idle check engine light back on, code returned Peake FFC9 Bank 1, Bank 2 no codes. I noticed the lack of power between 2K-3K rpm again.

I made it to my destination and let the car sit for about 3 hours to conduct my business. I came back to start the car and same symptoms presented. I had another used cleaned MAF so I changed it and cleared the code, the car did not run well at all. I went back to the previous MAF and drove home on the highway without much difficulty and no lights, but still noticing the loss of power between 2K-3K. I made it home and at a few stop lights the car idled with no check engine light, however the code FF C9 is still present when I checked the car this morning.

Any suggestions? Would O2 sensors give me trouble like this? I have replaced everything ignition wise but o2 sensors and MAFs..... I am hopefully putting new crank position sensors on this weekend if the dealer gets the right ones. It seems the symptoms want to come and go and changing the MAF really helped but then the fault came back and so did the symptoms after a 2 hour drive.... I smoke tested the car the other week after resealing intakes and it checked out. I will smoke test it again since I have put in some driving hours.

Any help would be appreciated....this car is getting better...just needs a little more!

James

Did you already check things like fuel pressure at the back of the engine fuel rails?
o2 sensor problem would not cause the problems you are having....
Very difficult to properly diagnose E31 with something like the peak tool, you need real live values with INPA or DIS to point you to the right direction.

[rjjablo]

While you are waiting I would check Cam Position and Crank Sensors with an Ohmeter

[jimmythefish]

Did you already check things like fuel pressure at the back of the engine fuel rails?
o2 sensor problem would not cause the problems you are having....
Very difficult to properly diagnose E31 with something like the peak tool, you need real live values with INPA or DIS to point you to the right direction.

Hi Dragon850, yes I tested the fuel pump pressure behind rails, and pressure regulators all working within specification. I did put new pumps, filters, screen, and lines for the fuel system and tested to be sure all was working, because I thought that maybe my workmanship was lacking....lol.

I will have to find someone with INPA or DIS because I bought one off ebay a couple years ago, but I am too stupid to use it and do the necessary set up. My mechanic had a GT1 but it stopped working (yellow head) and he hasn't replaced it yet.

[jimmythefish]

While you are waiting I would check Cam Position and Crank Sensors with an Ohmeter

If the crank sensors come in tomorrow, I will check the new ones and put them on. As for the donut sensors, though new, I will have to look up how to test them with the ohmeter, I did check all the new plugs wires before installing and they were right around 6 ohms, new coil wires at 1.9- 2 ohms.

Thanks for the leads! (punn intended)

[jimmythefish]

Update: continued difficulty, some more information to help solve the problem:
1). New crank position sensors installed
2) new a/c compressor and dryer installed with R12 recharged
3) inpa diagnostic laptop (thanks Dragon 850!)

ok, the car will run just fine when cold and warm, it seems that the car wants to go into a rough idle and throw check engine light after idling for 45 minutes. I smoke tested while engine was hot not leaks detected.
Right bank
“Code: 201 Lambda integrator regulator stop
Error frequency: 60
engine speed: 1000 rpm
load signal: 7.10ms

short circuit to ground
open circuit
exhaust gas relevant fault
fault stored after re-bouncing delay
error not present
sporadic error”

I ran the car at idle and looked at analog valve exhaust control
Right bank had a wider range than left bank on
“lambda sensor voltage” “ right .05 to .85, left bank .21 to .77
”lambda integrator” right -8.00 to 7.00, left -3.00 to 3.00
”adaptation value additiv” right 83.00, left -17.00
”adaptation value multiplicativ” right -14.00, left -1.00
the biggest difference and the right bank was way off range was for
“adaptive value TEV” normal range is -10.00 to 10.00 but the right was out of range the whole time -24.00 to -10.00, left was -7.00 to 0

so with all this information, what does this mean? The car will idle rough intermittently when warm, but not all the time, the rough idle can vary in severity and even refuse to idle, but this is not always consistent.

any help is most appreciated, I am considering overnighting some new O2 sensors since that is about the only thing I haven’t replaced on the car. Thanks!

James

[Timm]

It points to a vacuum leak on the right bank (which is the left bank when viewed from the front) - most likely completely disintegrated PCV valves.

[jimmythefish]

Hi Timm,
PCV valves are brand new including the rubber hoses/grommets.

[LappingLuke]

What is the MAF voltage signal with the key on engine off?

[jimmythefish]

LappingLuke bear with me;
key on engine off right bank
general analog values
Ignition angle (grad KW) 72which is way out of spec since should be between -10 to 10

analog valve exhaust control: everything is in spec
lambdas sensor voltage .07
lambda integrator 4.0
adaptionvalue additiv 96.0. On high side but within range
adaptation value multiplicativ -14.0
TEV 2.0

[jimmythefish]

Checking left bank which has no codes
the key on engine off
ignition angle reads 72 as well assuming that is normal

left bank analog value exhaust control
lambda sensor voltage .09
lambda integrator-4.00
adapt additiv -17.0
adapt multiplicativ-1.0
TEV -2.0

keeing in mind this bank seems to be running fine with no codes

[cartoonz]

what is the point of reading things like ignition angle and lambda adaptations - with the engine NOT running?

[Timm]

This will help you understand the INPA values: https://www.meeknet.co.uk/E38/Diagnostics.htm

I think to rule it out, I would swap the MAF's over, clear adaptations and then do the tests again - your results could well be a faulty MAF, but it could be lots of other things too!

[jimmythefish]

Cartoonz and Timm, thank you! I have no idea of what the actual purpose of that exercise but posted since it was suggested. I will read the link Timm supplied. I was reading on here a thread where Dragon850 was having some similar issues that he put new O2 sensors, but had a “Chinese MAF” that may have messed with the values too.

I will switch the MAFs and clear the adaptations.

clearing adaptations? The safest way would be to unhook the batteries for 20 minutes?

[rjjablo]

Magic Reset is unhook both batteries completely. Turn the key to position 1. Connect the Positive Battery Cable to the Negative Battery Cable on both sides, I used a Clamp on the right and a set of Jumper cable on the left. Let sit for 20 Minutes, Connect it back up. This will clear the capacitor and all the values. Make sure you are not touching the battery with anything during this.

[dragon850]

With the engine on and idling, can you take a pic of the exhaust value screen, especially interested in Air intake volume at the top right I believe.
Post both screens L and R bank

[cartoonz]

With the engine on and idling, can you take a pic of the exhaust value screen, especially interested in Air intake volume at the top right I believe.
Post both screens L and R bank

operative term being "with the engine RUNNING"

[jimmythefish]

Hi guys,
I switch the MAFs sides and did the magic reset (thanks rjjablo). Drove the car and the first 15-20 minutes was magical, then the crap started again, rough idle sometimes not wanting to idle at all while I was in stop and go traffic. I stopped at a friends house that has Autologic and he scanned the car running and told me that my O2 sensors are fried because while warm the values were continuing to fluctuate rapidly and he said and what I was reading from Timm’s link that the reporting from the O2 sensors should level off when warm.
Also, before I switched the MAFs the code 201 was on bank 1, after the switch it went to bank 2 following the MAF….however after that switch then bank 1 started to show a speed sensor code

Then, I drove home, ordered Bosch O2 sensors, unfortunately, won’t be here until early next week. I took a MAF from my E32 750 with 60K original miles, replaced Bank 2 (since the code did follow that MAF) did another magic reset and drove the car. The car ran better but still a hunting idle, check engine light flashed, I hooked up the INPA and took some pictures and I will post them tomorrow morning (I have a hard time posting pictures from my iPhone on this site). I forgot to get the code but will get that tomorrow morning.

Dragon850 if you want me to text you short video clip and/or screen shots I can do that, or email you the screen shots I can do that too.

The car gets an alignment tomorrow morning at a local shop, then if I have time, I might rob the pair of O2 sensors off my E32 750 and see if the situation gets better, but I do have to work tomorrow morning, get new tires for the 530 and a haircut…so time might be limited

for now I will go read me from Timm’s link so I have a better understanding.

Thanks to all of you! At least the AC is nice and cold!

James

[LappingLuke]

my O2 sensors are fried because while warm the values were continuing to fluctuate rapidly and he said and what I was reading from Timm’s link that the reporting from the O2 sensors should level off when warm.

This is not correct is it? The o2 can only tell the DME if the mixture is rich or lean and the normal operation of the engine controls is to chase the mixture back and forth across stoichiometric ratio from ever so slightly rich to ever so slightly lean constantly therefore fluctuating constantly.

- - - Updated - - -

I think you may have misread Timm's article.

"Lambda probes do nothing at all until they have reached operating temperature and this value will stay stationary for a couple of minutes"


They will read a stable value UNTIL they are warm, not once they are warm. This is because they can't work until they are screaming hot.

[jimmythefish]

Lapping Luke, thanks I apologize for not being accurate on my that part of the explanation. I think my friend, prior shop owner, referred to the specific values were fluctuating into extreme ranges beyond where they should be, since the O2 sensors have not be replaced he suggested that I start there as a reasonably priced "rule out."


Ok screen shots below, the error 201 code did follow the MAF when I switched it from bank 1 to bank 2. Then, I replaced that MAF with another used MAF off my E32 750 (running) and this code came back again on bank 2. Bank 1 remained clear of codes this time no speed sensor code.




0EE3A237-1D49-4474-AF87-482DB29FD3D0.jpg

3FB28B71-0D71-43BF-8927-01B5BB75564B.jpg
Above is bank 1, described as right bank on INPA

2BDBD96F-95DA-4145-AC38-4AFAF4A99A05.jpg
Above is bank 2, described as left bank on INPA, this is the side showing the 201 code

During these screen shots, the car was running, warm (drove about 1 hour) and idling rough/hunting. Honestly, I hate to hear it run when warm because it just sounds so strained. Cold, the car sounds fine but still think a slight rough idle that gets worse once warm. The car starts easily cold or hot, so if it stalls at a stop light it immediately starts.

Thanks guys,

James

[LappingLuke]

Code 201 means that something is so bad that despite its maximum effort, the DME can't correct the mixture. On one bank you have a Lamba integrator value of -12 which means the mixture is consistently running rich and the adaptation is subtracting 18 from the injector on time but also multiplying by 0. Is that basically turning that bank off?

Definitely still curious about your MAF sensor reading with the key on engine not running. Have you checked for vacuum leaks with smoke tester or my personal favorite spraying brake clean all around suspect areas?

And for clarity, were these data captured at operating temperature after a magic reset?
code 201.JPG

[Timm]

The multiplicative adaption of zero is OK - it uses the displayed adaptation value divided by a factor (unknown what the division factor is) then added to 1 - this gives a more accurate adjustment than could be sensibly displayed and stored.

[jimmythefish]

Lapping Luke, I have smoke tested the car 3 times warm and cold situations and have not found any leaks.... There are somethings going on that the DME cannot adapt to hence tripping the code. One thing for sure the 201 code followed the MAF and even came back with another OEM MAF installed.

The screens shots were taken after a magic reset followed by 2 hours of driving time. My friend is about 1 hour away and the car literally limped into his driveway and he told me about 7 years ago, I told you to never buy an 8....lol. All jest aside, he scanned it with his Autologic after 1 hour of driving from magic reset, and symptoms were present/ code was present then. He did not clear the code and I drove home 1 hour and took the screen shots....in full disclosure.

Thanks everyone for your help
James