XSeries-forum

Hi all

Just found this forum courtesy of a member from another forum. If anyone has any answers to my problems, it will be found here. Are you all sitting comfortably/, I shall begin.

As the title suggests, i need some expertese regarding some problems ive been having. I posted this in the bimmerforums site and all i seem to get on there is people telling me what im not doing, rather than what i should. Here goes.

I bought a rather nice 90k 2003 3.0 petrol and when i bought it i was told it had a missfire. That was no biggy for me as ive been playing with engines for years and have never not been able to fix one and, given that i liked the price and was getting a full history with only one owner, i went for it.

I dont wish i hadnt as i know that every can be fixed but im getting beaten by this car.

I started with the basics, new coils, plugs, and a service, inclusing all the relevant fluids and filters and made no difference at all. The coils were Bosch one and so were the plugs but i was then told that i should have used NGK plugs, which i did and strangely it made the missfire (or what feels like a missfire) a little better, but it didnt go away. Its also worth mentioning that there has always been a strange whining noise coming from the from right right hand side of the engine bay.

Then im thinking ats an issue with the PCV setup as we all know that can cause problems, so i remove the inlet manifold, along with all the old hosery, cleaned the area and upon doing this i found something very weired and something i have never seen before.

There seemed to be some kind of chemical metal had been applied to the area of the head just abou the hard coolant hose. I could also see that coolant had been running sown this side of the head as well.



So obviously this rang alarm bells as firstly i was asking, why was coolant leaking from the head, and it meant that someone had been under the bonnet before me. So i decided to remove the head to see whats going on and i found this...





What on earlth would cause the coolant channel to oxplode outwards like that? How could there be so much pressure in there to cause that? Anyway i sourced a replacement head, together with new head bolts, and a rebuild kit fo the Vanos and fitted those.

I also noticed upon stripping the engine that everything below the inlet manifold was covered in a fine film of oil and the pan at the bottom was covered in it, and by the looks of things, it had been dripping down there for a while, but upon inspecting all the normal gasket and seals, there were no obvious signs of a leak. Im now puzzled at this point.

So head removed and replacement is refitted together with rebuilt vanos..






...and everything was back together including all new hoses and PCV valve, and nothning at all changed. It was running just the same as before. The only difference this time is that prior to changing the head it was consistantly bad all the time. Now it seems to vary. Sometimes the lumpiness is only slight and at other times its virtually undrivable, but it never stops.

Its worth mentioning that i had a basic OBD reader at the time and before removeing the head i put it on the car and i got messages saying "Missfire Cylinder 2 with low fuel" and sometimes i would get the same for cylinder 4 and then at other times it would report "various missfire detected"

So given that i am commited to fixing this, and the only thing i ever go to a garage for is an MOT, i pressed on.

I thought perhaps my MAF was on the way out as sometimes i would get a message on the dash saying "trans Failsafe Prog", and given that so many things report to so many sensors i replaced the MAF, and while i was at ii, i got a replacement inlet manifold just in case there was some kind of leak in the one i had, as i performed a smoke test and it revealed nothing. So it then had a replacement inlet manifold, maf sensor and intake boot, cause i know how those things can develope leaks, and nothing. No change whatsoever.

if anything it seems to be getting worse because when the weather is cold, and only upon a cold start it seem to backfire into the inlet manifold, and this seems random, with the only common thing about this is that it is only at cold start. And its still chucking out oil from god knows were as threre are no visible leaks. Was wondering if its blowing it out of the PCV system. But what would cause that? I even replaced the fuel jump just for good measure to rule out any problems being caused by this.

https://hosting.photobucket.com/images/ ... 228(1).mp4

Not sure if this link will work but its a short video explaining the strange whining noise coming from the right hand side (as you look at the car) of the engine.

I was on the virge on just putting another engine in there and be done with it until some more strange things started happening..

Im getting random message in the car such as, "check oil level", and the oil level is fine. "Low Coolant" when the coolant isnt low. Check oil pressure, but i cant check this. I also get messages telling me that various bulbs are out on the car when they are fine and working. And most recently ive just got a new issue when upon leaving the car and locking it, the hazard lights start flashing for no reason, and switch in the middle does nothing. Also while driving i can go to indicate, and from moving the indicator to the actual indicator flashing, is a very noticable pause, and upon moving the indicator stalk back, again there is a similar pause. But again, this is intermitten as its not like this all the time!

Following on from all of this with no answers, someone has suggested to me that this could all be casused by a faulty ECU. I thought this was unlikely because i dont see how a faulty ECU could explain the whining noise and the oil loss, and i have never had an EML light come on. But i decided to investigate by actually having a look at the ECU, So i located it and took it out to have a look inside..



and from the top all looked ok..



and looking at the underside of the pcb, all looked ok until i noticed thison the left



Now this might be something or it sould be nothing but i thought i d put it on here anyway to see what people think.

So just a summary of what its doing and what ive done..



Very bad to mild rough running with missfiring upon cold start
Bad oil leak but seems to be coming from the breather system as no other seals show signs of leakage
reaplcement head, head gasket and new head bolts
repalcement inlet manifold, manifold gasket and breather pipes and PCV valve
plugs
coils
MAF sensor
Cam position sensors
hard coolant hoses
intake boot
VANOS seals and solenoids
fuel pump

...and still im none the wiser. Im kind of hoping that it could be the ecu, as replacing that is easy, but i am fully prepared to replace the engine if need be, I have tried using INPA and ISTD on it but cant get it to connect properly and im not IT leterate in any way but any obd reader i put on it still gives me missfire codes!

HELP PLEASE!!!!!!!

Hope all are well

Hello and

Initial thought is - have you run a pressure test on all 6?

Hard to tell from the pictures, but were all the valves the same across all 6? What I mean is, colour of each valve common? It looks as if three sets are darker in colour. Might just be the lighting though

Before fitting the head, did you check the new head and original block for flatness? That kind of cracking could result from a twist if a previous owner failed to follow tightening rules and sequence. Could also be down to a coolant loss event causing overheating.

The inside of the ECU looks like normal flow soldering to me. Solder paste is applied from a mask, components placed (by machine) on top and the board goes through an oven that melts the solder and bonds everything. I don’t think anything is missing, that patch has never had anything soldered to it.

IGNORE - Diesel only (thanks Marti): Have you got a ‘vortex’ type PCV oil strainer? BMW fitted ones that looked like a foam bog roll and these are known to clog and cause pressure build up. The later version is a vortex - no foam. They were fitted to diesels and I’m not sighted on what is on the petrol version.

Coil packs are a known weak spot. However given you’ve changed them (all?) that eliminates it. Worth checking the condition of the wiring loom though. Could be a temporary (when cold) short to ground, or no trigger signal (>2001 engines may be multi-shot spark per cycle). If you swap coil packs of the dodgy cylinder to any other position, does the ‘fault’ move? Diagnosis of the multi spark system needs DIS and a special tool from BMW.

Worth checking the injectors as well, spark may be the cause but….

I’ve never seen a BMW head do that either! I don’t think I’ve ever seen that kind of damage on this forum. I’ve seen iron heads crack, but that’s only if it’s been run waaaayy over temp and run dry.

X5Sport wrote: ↑Tue Sep 20, 2022 2:33 pm Have you got a ‘vortex’ type PCV oil strainer? BMW fitted ones that looked like a foam bog roll and these are known to clog and cause pressure build up. The later version is a vortex - no foam. They were fitted to diesels and I’m not sighted on what is on the petrol version.

X5sport, PCV's on petrol BM's are rubber diaphragms, well they were on my 2001 7series.....Im sure they still are, just a heads up to your vast knowledge .

Thanks for the tip. My petrol knowledge is back in 1998. Have burned demon fuel ever since…with none, one or two turbos. Going electric once the blasted thing arrives (12 months yet!)

OK forget the vortex breather! Just a thought…but the wrong line entirely. I need to consult my oracle……..

Send the ecu away for testing it wont fix the oil loss or noise but it may well be the cause of the misfire , you simply cannot tell if its any good by looking at it The head damage was most likely a frost crack due to low antifreeze and random low coolant warnings on start up are just the senor is bad or dirty . Some right bodger has been there before though to do that

X5Sport wrote: ↑Tue Sep 20, 2022 2:33 pm Hello and

Initial thought is - have you run a pressure test on all 6?

Hard to tell from the pictures, but were all the valves the same across all 6? What I mean is, colour of each valve common? It looks as if three sets are darker in colour. Might just be the lighting though

Before fitting the head, did you check the new head and original block for flatness? That kind of cracking could result from a twist if a previous owner failed to follow tightening rules and sequence. Could also be down to a coolant loss event causing overheating.

The inside of the ECU looks like normal flow soldering to me. Solder paste is applied from a mask, components placed (by machine) on top and the board goes through an oven that melts the solder and bonds everything. I don’t think anything is missing, that patch has never had anything soldered to it.

IGNORE - Diesel only (thanks Marti): Have you got a ‘vortex’ type PCV oil strainer? BMW fitted ones that looked like a foam bog roll and these are known to clog and cause pressure build up. The later version is a vortex - no foam. They were fitted to diesels and I’m not sighted on what is on the petrol version.

Coil packs are a known weak spot. However given you’ve changed them (all?) that eliminates it. Worth checking the condition of the wiring loom though. Could be a temporary (when cold) short to ground, or no trigger signal (>2001 engines may be multi-shot spark per cycle). If you swap coil packs of the dodgy cylinder to any other position, does the ‘fault’ move? Diagnosis of the multi spark system needs DIS and a special tool from BMW.

Worth checking the injectors as well, spark may be the cause but….

I’ve never seen a BMW head do that either! I don’t think I’ve ever seen that kind of damage on this forum. I’ve seen iron heads crack, but that’s only if it’s been run waaaayy over temp and run dry.

I replaced all the coil packs with BOSCH ones along with the plugs. Strange thing is upon moving the coils around it initiall moved but not in accordance with the way i moved the coils. Then it went back to its original position before i swapped back the coils, so it doesnt look like its that.

Hi all

My reapcement ECU, EWS, Ignition barrel, key etc turned up so when working hours permit, it shall fit them.

There is one characteristic that i forgot to mention in my earlier post and that concerns the MAF. When i initially got the car, and replacing the coils and plugs had no effect on the rough running, i suspected the MAF could be at fault as it was not a VDO one. I changed it for another (again not VDO) and as you expect, nothing changed. Then i got a used VDO one, thinking that using an "original" would maybe help and no, it didnt. But even now, if i disconnect the MAF, even though there is still a very slight wobble there, it runs near enough perfect. However, upon doing this i get a message on the dash saying "TRANS FAILSAFE PROG" and the gearchange is all weird.

So just to summarise, i have replaced the MAF 3 times and it never changed anything but if i unplug it, it is 100 times better.

Any further ideas peeps?

Hope all are well
Phil

Are you getting any warning codes showing when doing a code scan? If so what ones? Note - if possible use a tool that can scan the proper BMW codes rather than the generic ‘P’ codes. It makes decoding them easier.

This website will help with understanding them: https://bmwfault.codes/

If your getting the failsafe for trans, that points to a low battery voltage in most cases, as for the maf if it runs near perfect with it disconnected thats because its running on default settings, sounds to me like you need a new genuine Bosch maf (non oem mafs are a waste of time),, they are supposed to be changed every 50 to 60k.....however as x5sport has mentioned BMW codes would be handy..

Well, the replacement ECU, EWS and all the bits has been installed, and i suspected that the MAF could have been damaged by all the backfiring that was going on previously, so i borrowed a known working VDO unit from a friend and low and behold.....the car runs perfectly. No wobbling, missfiring and no more numerous warning lights about anything and everything.

Looks like my gamble regarding the ECU paid off, on this occasion anyway. Just ordered a new VDO unit from AUTODOC in germany and itll be here in a few days, then hopefully thats my m54 Headache over.....for a while anyway.

Glad to see that you’re getting somewhere now.