The time has come

[Zerocool818]

I may be way off here (never stopped me before though) but what size tires do you have on it? I seem to recall when I was searching for tire combos for mine that if the size of your fronts and rears were too far apart it would cause all kinds of squirrelly stuff to happen with regards to speed sensor errors.

Errr, stock staggered setup? I believe the sizes were the same as OE. ( on that note I do need tires but I need to finish the driving issue first)

[Zerocool818]

OK; Updates.

-Got the car smogged! Took a while, found a slightly broken injector I swapped out ( luckily I had 2 sets) Replaced some O-rings and a few other brittle vacuum hoses and sure enough, within 50 miles all the monitors set and no check engine. Got it smogged and registered today.

-Radiator is leaking, that will be replaced.

-Transmission service took away the whining noise, however it still erradictly shifts. A friends 'Fancier' scanner picked up a code for transmission overheat.
Did some research, apparently these have a regulator/thermostat valve that fails. However It seems that pre-facelift had a seperate cooler in front of the radiator, where the facelift had a coolant heat exchanger. I live in so-cal, it doesn't get real cold around here. So I would like to convert it to a standard transmission cooler in front by modifiying the lines and running a large transmission oil cooler in front of the radiator.
I could possibly use stock parts to do this, or I am debating doing a custom route and just using regular off the shelf parts to accomplish this.

-Speed sensor is still off, I am planning on just replacing sensors one by one and hoping it goes away. I don't have a scan tool that will tell me which is at fault, however a visual inspection showed that pretty much all have brittle wires, so probably not a bad idea to replace them all anyways.

-Alarm keeps going off, this is probably the most annoying to me as I have to lock the car from the backseat, and I can't use keyless locking.
I probably have a bad sensor as it goes off 15-20 minutes after using the key

-Still need to replace the batteries. Might do this first as I know these things are sensitive with their batteries


But so far so good! At least now I can drive it around without fear of getting d*cked for expired reg.

[Manny G.]

OK; Updates.

-Got the car smogged! Took a while, found a slightly broken injector I swapped out ( luckily I had 2 sets) Replaced some O-rings and a few other brittle vacuum hoses and sure enough, within 50 miles all the monitors set and no check engine. Got it smogged and registered today.

-Radiator is leaking, that will be replaced.

-Transmission service took away the whining noise, however it still erradictly shifts. A friends 'Fancier' scanner picked up a code for transmission overheat.
Did some research, apparently these have a regulator/thermostat valve that fails. However It seems that pre-facelift had a seperate cooler in front of the radiator, where the facelift had a coolant heat exchanger. I live in so-cal, it doesn't get real cold around here. So I would like to convert it to a standard transmission cooler in front by modifiying the lines and running a large transmission oil cooler in front of the radiator.
I could possibly use stock parts to do this, or I am debating doing a custom route and just using regular off the shelf parts to accomplish this.

-Speed sensor is still off, I am planning on just replacing sensors one by one and hoping it goes away. I don't have a scan tool that will tell me which is at fault, however a visual inspection showed that pretty much all have brittle wires, so probably not a bad idea to replace them all anyways.

-Alarm keeps going off, this is probably the most annoying to me as I have to lock the car from the backseat, and I can't use keyless locking.
I probably have a bad sensor as it goes off 15-20 minutes after using the key

-Still need to replace the batteries. Might do this first as I know these things are sensitive with their batteries


But so far so good! At least now I can drive it around without fear of getting d*cked for expired reg.

Unplug the hood sensor for the alarm. I've found that on both the E39 and the E38 both suffer from engine bay heat and ultimately damage the alarm sensor that recognizes the hood being opened. It is located by the passenger headlight.

The rear driver side sensor is the one which tells the speedometer what speed the car is going. The others have a specific function as well, just dont remember them all.

Has your ebox ever gotten wet or checked for water inside? Your transmission symptoms sound like a wet transmission computer also... maybe not but worth a check. Also, the transmission has a temp sensor built into the harness which connects to the solenoids,.. could be heat damaged if the trans ever over heated.

Good luck

[Zerocool818]

Unplug the hood sensor for the alarm. I've found that on both the E39 and the E38 both suffer from engine bay heat and ultimately damage the alarm sensor that recognizes the hood being opened. It is located by the passenger headlight.

The rear driver side sensor is the one which tells the speedometer what speed the car is going. The others have a specific function as well, just dont remember them all.

Has your ebox ever gotten wet or checked for water inside? Your transmission symptoms sound like a wet transmission computer also... maybe not but worth a check. Also, the transmission has a temp sensor built into the harness which connects to the solenoids,.. could be heat damaged if the trans ever over heated.

Good luck

I have heard about the hood sensor, I will try that.

The Ebox may have gotten wet, now that you mention that, the cover was off throughout some rain, I will try drying it out and make sure its dry



The weird part is, when the transmission acts up, it randomly downshifts and holds it. I thought this was overheating and then this morning it did it right when it was started up. So it could be a bad trans temp sensor as well causing it to think it has issues.

However I try to manually shift and it doesnt work either. It will refuse to upshift manually too.

[Zerocool818]

So quick update, got my usb to obd2 scanner today and hooked it up using INPA.


Shows trans temp is at 190C

I checked with a IR temp gauge
It’s at 90c

Sooo I guess I have a bad transmission harness, right?

Also it started hard shifting today,
Very jarring like slamming into gears

Filter and fluid were recently done

Like 500 miles ago.


Will check level on trans make sure it’s good but I think it’s just the temp sensor acting up

[Sleepyhead97]

Doesnt the computer NEED MAF input for transmission shift points? I think yes as my e39s do. TLDR but dont ignore MAF code. Replace OEM. LKQ might have one

[Zerocool818]

Doesnt the computer NEED MAF input for transmission shift points? I think yes as my e39s do. TLDR but dont ignore MAF code. Replace OEM. LKQ might have one

The MAF's are new, It did just throw a code for bank 1 lean, Which is probably the injector o-rings since I only replaced the bank 2 side. Thats what I get for being lazy.


That and I do need new batteries, a few error logs showed low voltages ( I couldn't read the german but I could see 8 volts and error)

So new batteries, new transmission harness, and go from there.
I might also replace the transmission fluid regulator/ thermostat also, though I don't think its actually overheating.

I will scan with INPA again when the cars cold. if it shows the trans temp is any higher than ambient then I can safely say that the sensor is most likely bad. I read that its a common occurance for the sensor to go out, or the harness leaks oil through the physical connector.


I couldn't get the INPA to read my EDC either, I have an issue with the S-edc not working. I believe its the module.



Newest thing that came from the INPA, was that all the wheel sensors are reading the same pulse. I still have a miscalibrated speedometer. I am wondering if the speed is also detected through the transmissions speed sensor. I was alone so I couldn't be messing with the INPA as someone was driving to see what the transmissions speed sensor was doing.

Though as it was pointed out, the E38 is supposed to get its speed reading from the left rear ABS sensor, So I am once again clueless as to why my speedometer is reading 10mph off. Its the OE tire and rim combination as well.

[Zerocool818]

OK, Kidney sold.

Got a new transmission harness, new radiator, expansion tank, coolant hoses, thermostat, fan clutch.

Will be replacing everything and bringing the cooling system up to date. The hoses are dated 2000, I doubt they had much life left in them.

[Grady in Texas]

Did you get new batteries too. These cars get very squirrelly when the voltage gets low. Mine is in the shop for an alternator/regulator issue.

[Zerocool818]

Ironically no, I am getting them tomorrow. I think its just batteries but the lights do flicker. Then again the batteries are garbage.

That being said, After a car wash, my trans goes into a "limp" mode where it will keep the lowest possible gear. After some searching around it seems that the trans harness is the issue.

However there is evidence there was water in the DME box, the covers just been sitting loosely.

I will take apart all the connectors and clean them out thoroughly. Hopefully nothings been damaged.


Sunroof also thinks its pinching, its a gamble to open it. Minor issue though. Just spend another $600 in cooling system components


I also found out my transmission was a bit leaky, just a loose bolt. However I think I lost some fluid.

[Zerocool818]

I am assuming when I have 2 brand new batteries, and my voltage dips to 12.8 at idle at a light, that it could possibly be a dying alternator or regulator. ouch

[Zerocool818]

So updates (if anyone cares)
Swapped a rear window regulator, broke a piece, tried repairing it, thought it worked. And it’s creaking again. But it stays up!

Got new tires, rides much nicer, Pirelli all seasons

Trans is acting up again. Never changed the harness but it’s a new issue.
If I floor it, it’s like it gets stuck in gear right before it shifts at redline, I believe the fluid level is low.

Also sometimes kicks 1-2 at low speed low acceleration.

My driveshaft rubber piece (guibo?) is cracked, that needs to be replaced.

All coolant hoses/ thermostat/ radiator were changed
New fan clutch also

Temp now sits at 107-108 degrees
(And it was like 110 in LA the other day so it’s working great)

However my water pump has rust in it so that is on the later to do list.



Ac is working great, but only on face, if you set it to windshield or feet it instantly blows hot, like the heater is on,
Also believe the AC could be colder. Friends E46 blows colder and I doubt it is better from factory than mine.
I believe the heater control valve is stuck open making it so the heater is constantly circulating.
Weird part is, if I set it to full heat, and turn up the dial on the dash to heat. The dash vents never get anything other than mildly warm, like 80 degrees,

I wonder if I have a flap issue or the motors are not synced properly, I couldn’t find any information on resetting them.

Also need the usual steering/ suspension components as the front and rear end have some decent wobble to them.


Some days I wonder if it was a mistake buying this thing, but I haven’t driven my other car in a month now. Screw the fact I get 12 MPG. Really do like this thing, just tryna shorten the list instead of expanding it

[Timm]

Got new tires, rides much nicer, Pirelli all seasons

Trans is acting up again. Never changed the harness but it’s a new issue.
If I floor it, it’s like it gets stuck in gear right before it shifts at redline, I believe the fluid level is low.

Also sometimes kicks 1-2 at low speed low acceleration.

That sounds like the rolling radius of the tyres are wrong between axles - or across them:

https://www.meeknet.co.uk/e31/Timms_...20on%20ASC.pdf

https://www.meeknet.co.uk/e31/Timms_..._tyre_page.htm

[Zerocool818]

I believe I have the stock tire sizes for the staggered setup.
255/45/18 and 235/50/18

[Old525i]

Slow progress. Thanks for that tip, I adjusted it and it immediately looks normal how. However I have a small SLS leak. I will have to remove that line and have a new one made. (Hydraulic shop nearby does all my hoses with extreme duty stuff)

was also thinking how cool it would be to remove that rod and add a little servo to adjust it on the fly.
Since I’m not planning on having any passengers anyways

All the interior stuff works except the sunroof is weird
Will act like something’s blocking it

Still gotta smog this thing too, but gotta fix the problems.


Is it wise to change only one MAF or both? They aren’t cheap

Do you have an address for that shop? Name?

[Zerocool818]

Do you have an address for that shop? Name?

Lukys Hardware Co
818-845-8338
3814 W Burbank BLVD 91505


I have not yet done my lines, but they usually handle whatever involves hydraulics/brake lines/ any type of line

You can tell them you were referred by Harry from World Famous 4x4

[Zerocool818]

New giubo went in.
Old one was scary looking.

Topped off trans fluid, took about a quart. Shifting at high revs feels better but still does it.

Checked tire sizes that’s all what is OE

I do have a issue with ABS illuminating randomly on rainy days, maybe it’s a bad wheel sensor.

Also still casting doubt on trans harness. Have a new one, it’s just a PITA.

Next stop, suspension woes

[Old525i]

Google Project Dubai BMW. The guy has done a great job at restoring various V12 cars. Plus he is very funny. His YouTube channel is M539 Restorations.

[Zerocool818]

Google Project Dubai BMW. The guy has done a great job at restoring various V12 cars. Plus he is very funny. His YouTube channel is M539 Restorations.

I have been watching him, Sreten is a cool guy. Its interesting. I got mine around the same time he got his. ( He has made more progress though, I don't have a lift or any time left now a days)

[Zerocool818]

Updates updates;
Replaced the transmission heat exchanger valve, boy was that thing filled with crud. Haven't encountered the 'stuck in 2nd' mode so far.
However the transmission still shifts weird, planning to do a harness and internal speed sensor as it occasionally throws a pending code for it.

All my suspension is pretty much blow, my brand new tires are eaten up. Planning on doing full suspension, as well as rear shock accumulators, my suspension doesn't move in the back what so ever.

Ordered a spare heater valve to mess with, along with a rebuild kit. These things seem like they all blow out at one point or another, and a 110* day in socal means I need as much AC as I can get, and having some hot coolant flowing when it shouldn't be isn't nice. The rebuild seems pretty straight forward.

Also ordered the rear headrest plastic piece, super annoying to deal with that noise in the back.

Slowly gathering all the parts I need, to try and finish at least the driveability of this poor thing. Seems as though it basically never got any service other than an oil change.

Getting all new ABS sensors and brake pad lining sensors, as well as new brake lines all around.

Also on the list, rear window regulators, C pillar is broken, headliner sagging. But I want to make sure it drives 100%, and I am prioritizing the transmission first. Already did a new OEM Filter and fluid, and that helped immensely, but I think the harness, new internal speed sensor, and new ABS sensors, will fix the weird hesitation on hard acceleration

[haynes740]

@ Zerocool818
Stay with it man, sounds like you have a good plan of attack.


Sent from my iPad using Tapatalk

[Zerocool818]

I Think I misdiagnosed the transmission. I have a reoccuring check engine for bank 1 lean. I know its the injector O-rings, but when I smoked it it was such a minor leak that I have been lazy about it. Then the other day, CEL came on, when I scanned I noticed that the lean code was actually a pending code, not a CEL. The other bank had a p0102 code stored, Mass air flow A circuit low. I believe its not a transmission issue, but almost want to say a misfire under load.

weird part is, it doesn't do it all the time. Only in certain gears.


I cheaped out on one thing, the MAFS. I think chinese just doesn't work on these cars. I will splurge and order some OEM units, and hopefully it will make a difference.
I have a slightly rough idle as well. ( Slightly being relative for a V12).


I also need plugs/wires. Is that do-able with manifolds in place?



Good note, I rebuilt my heater control valve My AC is now beautifully cold, and my foot vents work properly now.
Small thing but really important in So-cal. Only $15 in parts and some elbow grease.

[Zerocool818]

Ok, So after getting to the point of one check engine a day, I eventually replaced one MAF with one old OEM bosch one I had. I cleaned it and installed it. and now my transmission issue is gone! It revs all the way up and shifts perfectly.

Also replaced rear shock accumulators, those were rock solid. Definitely changed the ride

[Zerocool818]

OK, My car was running fantastic, temps were always cool, never had an issue. Now, after changing the trans heat exchanger, and rebuilding the heater valve, I am having issues. I bled the system following Tims method, and when that didn't solve it, I flushed the whole system with distilled water, filled and drained it multiple times with the heater valve open, disconnected all the hoses, allowed coolant to drain all the way out. Then filled the system with premix BMW coolant, and followed the bleed procedure all over again, having parked it on an incline and etc.

All the cooling components are new with the exception of the water pump itself. Thermostat, radiator, all the hoses, heat exchanger for trans, fan clutch, are all new.

Im a few days away from being irritated enough to rip out the water pump and just replace that too, I have a feeling after replacing all the stuff I got a clog somewhere.

Also checked the bleeder hose on top of the radiator, has flow both ways. That was previously clogged and I replaced the hose to remedy that.

I also dug out the wire for the MAP Thermostat, and grounded it, so that basically the thermostat heater is always engaged and running at lowest possible temp (85C).

Temps are as follows,

Ambient temps are in the low 80F in Socal

Cruising on freeway, 90C (perfect)
Gunning it on freeway 100C ( Also perfectly fine)
101C aux fan starts spinning up
Stuck in traffic, 108C (Operating according to internet, aux fan screaming at full speed)
Gunning it on streets, then stuck in traffic, then gunning it, got up to 117 C (Scary)

Now the issue I noticed, my cheap IR temp gun reads the radiator 10 degrees colder than the OBC, But the aux fan and the temp sensor both agree the engine is too hot.
I cleaned out the contacts on the engine temp sensor, and the aux fan sensor is new.
Fan clutch doesn't whoosh on take off all the time, but if the rad is really at 200F it makes sense the mechanical fan wont lock.
I did cover the front of the car with a towel, and it did engage the fan clutch to lock up.


I am stuck in a loop of overthinking whats going on with this system, when previously everything was working OK,

I ordered another heater valve rebuild kit, and I am going to rebuild the valve that originally came off my car. I believe possibly that it might have a source of an air bubble?
However both sides have proper working heat.

Fix one thing, break 2

[acspecialists]

Be patient with the cooling system, it is a bear. Never take the cap off without the engine running, I check mine right after a cold start. When filling make sure the front of the car is elevated. Every time you drain and fill you are starting over. Be patient, fill-drive-cool-fill-drive-cool-fill.

It sound like your fans are working, watch the gauge not the temps.