X5, E53 3.0i missfire problem

[selkent1]

Just an update all, but i decided to umplug the MAF and lo and behold, all backfiring into the manifold and really rough idling has stopped, with just the slightest amount of rough running, but barely noticable. So went and bought a Boasch unit at around 160 quid, and the result.....running lovely with no backfiring!

How can a faulty or cheap MAF cause backfiring into the inlet manifold?

Hope all are well

[dworthy]

Cheap parts can fail right out of the box, so good to see you have figured it out!

[bmwdirtracer]

I'm quite confused at this point. You had a BMW MAF, and returned it because that didn't fix anything. I'm not sure what part you put back on. But then you found the head was cracked, which you replaced, and with NGK plugs and I'm sure all new gaskets in the intake, everything was aok, except for a metallic noise. Now it's making the misfires and backfires again....or it's not, since you bought a new MAF?

If you have any further intake-type issues, I really have to (again!) recommend that you find someone with a smoke machine and do a smoke test, for 10 minutes. (Ebay has smoke machines for much less than the cost of a BMW MAF)

[selkent1]

I'm quite confused at this point. You had a BMW MAF, and returned it because that didn't fix anything. I'm not sure what part you put back on. But then you found the head was cracked, which you replaced, and with NGK plugs and I'm sure all new gaskets in the intake, everything was aok, except for a metallic noise. Now it's making the misfires and backfires again....or it's not, since you bought a new MAF?

If you have any further intake-type issues, I really have to (again!) recommend that you find someone with a smoke machine and do a smoke test, for 10 minutes. (Ebay has smoke machines for much less than the cost of a BMW MAF)

Hi all and apologies, ill make myself clearer.

I acquired the car with what the seller described as a missfire, and so whent through the process of effectively starting at the bottom with parts, and moving my weay up. The rough and very lumping running was there from the go, but the back firing into the inlet manifold wasnt. The MAF sensor was just one of the many things that i replaced upon trying to diagnose the rough running. The unit i took off was a VDO unit, which i made a mistake of throwing away, only to replaced it with a 30 quid one i got from ebay. It was my only ebay part, apart from the head, and it was obviouslyt faulty from the word go. Either that or these cars dont like cheap chinese parts.

Done about 100 miles or so at the moment and all it well. And i cannot explain how much of a benefit it is rebuilding the vanos unit. My other X5, same model as this needed it and i wish i had done it at the time.

Mental note, DONT BUY CHEAP CHINESE PARTS.

But how can a faulty MAF cause backfiring into the inlet manifold.

Phil

[selkent1]

Hi all

Just thought id bump this with an update.

Lets just say that because of this im very much on the virge of just scraaping the car. In all the years ive been driving and engines/cars ive rebuilt, none have beaten me quite like this.

I took everyones advice and finally got a smoke test done and nothing, no apparent leaks. So i decided to go all out and on top of everything else i have done i replaced the inlet manifold with a good used one, together with new gaskets, fuel rail, injectors and idle valve, together with a new set of vacum hoses and the result.......still the same. I even changed out the engine wiring loom just in case it was electrical and maybe i had a split wire or something similar, and it made no difference.

Again, when driving it seems fine most of the time. Start it from cold and its all over the place, backfiring into the inlet manifold, then once warmed up it kind of sorts itself out but idles like it has a missfire, but it doesnt. Sometimes the revs drop when idling to the point were you think its going to stall and evey now and again you get the "trans failsafe Prog" message, which normally goes away. This message also appears when i unplug the MAF, which incidentally is a genuine unit.

I am at a comcplete loss now. I was thinking that maybe it could be a fuel issue, so was thinking to throw a new fuel pump at it but im really thinking of giving up on this car. Abou the only thing i havent replaced is the block.

Oh yes and i forgot to mention but the weird muted whining noise still hasnt gone away, so i guess that noise wasnt anything to do with vacum.

Any Ideas Peeps?

Hope all are well

[dworthy]

Are you watching live data? There seems to be plenty of clues as to what's going on, just won't know for sure until you can see what the DME is seeing.

[selkent1]

Hi

thanks for another response. No im not looking at live data and have no acces to that kind of kit. You mention plenty of clues, what do you think given your experiance?

Regards

phil

[dworthy]

Back-firing into the intake tends to point towards timing issues, running rough cold, ect. So what I would recommend is getting a 20-pin OBD-II cable and INPA for your laptop. This is a cheap and effective way of watching live data, for you will see a green = good and red = bad. Also INPA is a dealership level diagnostic tool that is pretty much free, all you will need to purchase is a cable like this: NiceCheck K+DCAN cable USB Interface/Ediabas OBD CAN Diagnostic Cable with Switch : Amazon.co.uk: Automotive

[selkent1]

Hi again

Many thanks for all your responses so far, and thus i thought i would i would update whats been happening.

I havent been able to get the software and hardware mentioned by dworthy however, i did manage to find a colleague who had one of the Icarsoft devices and upon clearing the multitude of codes that popped up, everything from lean codes to missfires etc, which had presumably appeared as a result of the work i had been undertaking, one code/comment kep re emerging and that was the one for something concering the vanos. VANOS INLET CAMSHAFT END POSITION NOT REACHED.

Any ideas peeps?

I rebuilt the vanos when i changed the head, and everything was very carefully locked in place using the correct locking kit so nothing moved while the head was off, and just in case i replaced the inlet soleniod thinking that maybe that was causing the problem and it made no difference at all. I will not be able to use the other software mentioned, so apart from either setting fire to the car, or giving it over to a garage, which i know will involve me parting with tons of cash and probrably getting nowere, anyone else got any ideas ?

Someone out there has to have encountered a similar problem as mine. I did come accross someone who had the backfiring into the inlet amnifold provblem that i have and it was on youtube but the video and discussion has dissappeared.

Any help would be ideally appreciated. Ill just run through what i have done.



I got the car with what was described as a "missfire", and i knew the car so i took a chance on it and got it, then started with the basics.


New Spark Plugs NKG
New Coils BOSCH
New MAF SIEMENS
New cam position sensor (inlet and outlet)
Replacement Inlet Manifold (in case there was a crack i couldnt see on the old one)
New inlet manifold gasket
New Vacum Lines
New PCV and valve
New fuel filter
New Fuel pump ( ive seen examples of fuel pumps going bad throwing up codes etc)
New hard engine coolant hoses (yes nothing to do with the problem but did it while the manifold was off just as good maintenance)

I havent replaced the crank position sensor as i forgot.

Im really running out of ideas now. Someone at work suggested that i should get an EWS delete ECU as most of the problems occur during cold start.

Like is said peeps, any help appreciated.

Phil

[selkent1]

Just bumping this.

Anyone got any ideas or leads?

Phil

[bmwdirtracer]

I just read the above, and one thing spooks me greatly:

You took the vanos and the head off, an "had everything locked down so nothing moved"? But to take the head off, you took the timing chains loose... you cannot do all that, and bolt it back together, and put the vanos on, and assume nothing changed. In fact, you're not supposed to join the head and block with the engine in TDC position.

Sorry, none of that makes sense to me - do you have the factory directions for this job?

You're going to need to go back in and retime the engine by factory directions and hope nothing got tweaked.

[selkent1]

Hi and thanks for the info.

I have built and rebuilt many engines over the years and have never come across anything that says that an engine cannot go back together in TDC position, indeed that is the position they spend al their lives. I also rechecked the timing after i had fitted the replacement head and i am assuming that the problem is not timing based chiefly becuase when driving normally the engine is fine its only upon idle, and especially cold idle, that the problems of extreme lumpy running and backfiring into the inlet manifold occur.

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[selkent1]

Hi all

Just thought id bump this as i havent managed to sort things. Was thinking about putting in a replacement engine as im lost.

Any ideas peeps

[bmwdirtracer]

Without a bmw diag computer giving live data, there's no way to see where the trouble lies.

And, sorry, but it seems you rebuilt the vanos and timing and engine without using the instructions. Backfires into the intake indicate timing issues; certainly these misfires/backfires could be caused by other items too; but "VANOS end position not reached" tells me the timing/vanos is incorrect. I have also rebuilt many engines...and I always follow the directions.

If you could see live data, you could watch the smooth running values for each cylinder; you could watch the misfire count for each cylinder, if any; you could see the temp sensor values for IAT and ECT, and the O2 sensor values and long term fuel trims.

Without data, you're pretty much going to keep throwing parts; which has proven to be far more expensive than setting up INPA (free) on a laptop, and buying an adapter cable.

Sorry, but between not using the directions when setting up your vanos, and not having live data, you're shooting in the dark.

[selkent1]

Hi all

when assembling the engine i followed evey bit of literature i could find in the absence of there being no haynes manual for these cars and i did order a bently manual, but that never arrived.

So given that for some reason it is now no longer back firing into the inlet manifold, but is still running lumpy, but not consistantly. Ie, runs lumpy, turn it off then back on and it is better and so on, so can someome point me in the direction of some instructions, from start to finish, regarding the re timing of the engine including the vanos.

Regards

[bmwdirtracer]

Sure. PM me with your email address.

Click on "bmwdirtracer" in blue at the top of this post, click on "send PM".

[selkent1]

Chris,

Its not letting me pm you. Its not giving me the option. Anywere.

[selkent1]

Hi all

Well it would appear that after much head scratching and doubting myself it would appear that upon installing the replacement head and rebuilding the vanos unit i had indeed timed the engine correctly, thanks to lots of help from Chris on here. However thats good in one respect but it doesnt get me any closer to curing the issue.

I gave up trying to get INPA to work, instead i opted to use ISTA-D and it seems to be pointing to an issue with the ECU or (DME) as bmw call it, but its not being any more specific than this. Plus its also worth mentioning that the issue with what appears to be miss firing is very speradic. It never completely stops but sometimes its only just noticable and other times its so bad its barely drivable. Also, im getting a lot of error messages that turn out to be fake. I get messages telling me that lights are out when they are not, especially number plate lights. I get messages telling me that the air suspensions in not working when it is. I get messages telling me that the oil and coolant levels are low, when the levels are actually fine and i getg another one telling me to check oil pressure. The pump has been inspected and is fine. And just for good measure i still get the occasional message telling me that its in "TRANS FAILSAFE MODE", and that normally go out either after a few mins or upon next restart. I just drove it this morning for roughly an hour and even though the sensation of "mising" was still there it was barely noticable and it was behaving like a normal car. Then upon restartng it behaved like a pig for a bit then sorted itself out.

I was just going to get an EWS deleted ECU and throw that at it to see if makes any difference but i thought id get the info on here first. Any ideas peeps?

Regards

Phil

[selkent1]

Hi again

Further to my earlier post. I have a few additional symptoms which include, hazard lights flashing for no reason after the ingine is switched off and hazard switch has no effect. And earlier i started the car and had no instruments at all, and it took a restart for them to return to normal. This all seems to be pointing to something electrical. I ran ISTA-D again and again the same results.

https://hosting.photobucket.com/images








Each time i run it, the program tells me there is an issue with the ECU but nothing more specific.

Any ideas Peeps?


Regards
Phil

[328 Power 04]

It's more likely you're not using the correct diagnostic interface or your setup for the interface isn't correct.

Basically there's no communication to the car as far as I see. No need to blame the car yet.

We need details on what cable you're using, what settings, and what setup.

[selkent1]

Hi all

Thanks for the information regarding the setup of my software, it wuld appear that it was not up correctly regardint the ports, but i think there is still a communication problem. I got the K+DCAN cable switch set to the right position and the drivers are correct, but i think things are still not well. Upon running a test for errors the tree i see is this...



Sorry sbout the quality of the pic


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The other screens are similar to this..







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So while i set about scratching my head regarding the isues im having with the software i decided to put my little basic reader on the car again and it just gave me the same errors it has done all alone and they are

Missfire Cylinder 2 with low fuel
various missfires detected
missfire cylinder 4 with low fuel

Cleared them and they came straight back. Not sure how relevant it is but i have never had an EML light on. Not once.

I was talking about this at work with someone and they suggested, given all the work that has been done on the engine, and the fact that it appeared to make no difference, that it could be the ECU (or whatever it is that BMW call it), and so i removed it from the car and had a look inside and the top seemed fine...



And while taking a photo of the other side....





If you look closely at the nottom right hand corner there seems to be some discolouration on one of the solders. Could this be the problem?





Anyone think this could be the problem?

Hope all are well
Phil

[selkent1]

Hi all

Well i thought i was starting to get to the borrom of things and finally sorting my m54 lump out but as ever, no. I recently did two trips to luton airport, which is a journey of around 100 or so miles and the car ran better than it was donrsince i have had it. Barely noticable rough running and and quite happily sitting at 80 or so mph for extended periods of time. Then about a week or so after it got really bad again. I noticed that there was a small split in the intake boot and so put the increased rough running down to that. I got a repalcement boot and it made no diference. Strangely, it seemed worse. This morning i finally got a compression tester and did a test and it looks like cyl 2, the one that has consistanty reported miss fires, is dead with less than half the compression it should have.

Ran test on 1,3,4,5,6 and got results around this mark



However cylinder 2 gave me this score...



And using the old trick of adding oil to the cylinder the score went up to this..







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So peeps

Am i to assume from those results that its replacement engine time?

I gather trying to replace piston rings etc, while the engine is in situ is a no go????

As usual, any help is appreciated.

Phil

[selkent1]

Was thinking about maybe pouring some kind of solvent or maybe seafoam into the bores and leaving it to soak. Thinking that maybe the oil scraper ring is all shitted up and not gripping the walls. When i added the oil the pressure went up by just over double!

Ive seen a few videos on this but not sure of the results.

Phil

[selkent1]

Hi all

Been a while since i was trying the kind of "easy" ways to get to the bottom of the problem and even though the running of the engine seemed to be consistent, and i did get to the bottom the various vacum leaks, i decided to go belt and braces and take the lump out. So i found a decent 70k engine (M54B30), together will the service book from the car it came from, videos of them taking it ouit etc, and after a few days, plenty of rain, and a few new swear words its in and running just like a BMW should. It just purrs!!

However, and you knew there had to be a however!!!!

I am waiting on a new top and bottom radiator hose as the o rings were perished and trying to get replacements that actually fit is a mission. Thats not a problem, the problem i have however is what appears to be the gearbox. The car goes into gear fine, just like it always did, and goes backwards fine but put it into drive and its very slow, almost like its moving off in second or third. Also, the PNRD indicator on the dash is not showing what is selected like it did before i replaced the engine. As far as i know, i havent touched trhe gearbox. Never even removed the torque converter as i know they can be a pig to get back in.

The only other problem i had was a flat battery which i charged and nearly flattened again trying to start it, but it eventually strated with a jump and seems to be charging fine as i have started it daily with no probs.

Any ideas peeps???

Hope all are awake and well"!!

Phil

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Oh

I forgot, just an update on the old engine. The reason for bad running was a hole in number 2 piston. Must have been about 1,, in size, maybe even smaller. No amount of marvel mystery fluid was going to sort that out!!