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Discussion Starter · #1 · (Edited)
Hi all!

So, now it's my turn (again..) to have some mysterious issues with the M. Have searched forums and google for answers for a long time now, and now appeal to the expert group in here :)

Symptoms: Loud ticking from engine from 1500 rpm and upwards ~20-70% throttle, no noise on full or no throttle, but on full throttle it seems only 4-6 cylinders are active. If I should describe the sounds, it sound like the valves are on a wrong timing and is getting beat up in there. Runs very rough on idle, but no distinct rattle/noise until throttle under load.

What have I done so far ? :
- Workshop checked for error codes, only came up with faulty Lambda, which turned out to be a loose wire, some of the other lambda sensors seemed broken (loose where the cable comes out) have baught new, but not replaced yet.
- Have taken off both solenoid banks and cheked o-rings and soldering (soldered some more to be on the safe side)
- Replaced oil and run the engine with oil cleanser first
- Vanos timing chain tensioner on bank 1 seems fine, have not checked bank 2 yet.

Engine was replaced with a factory new one in 2005 (rod bearing failure), and has 190.000km on it since then. Had a gasket leak 2 years ago, wich was replaced, along with 32 vales(!) when they mounted the timing chain wrongly upon assembly. Car has 318.000km on it now, hopefully it will live to see some more km's :)

Considering to take the covers off myself to check timing/tensioners/vanos, have read some excellent DIY here.

So to my questions, any ideas what I could check, or is removing the top covers best step forward ?
 

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I know you said error codes have been checked, but with 2 cylinders misfiring or similar i would expect to see some codes relating to such, or perhaps CPS codes because of duff sensors which also sound like misfires.

Is the garage using BMW specific diagnostics? Perhaps a GT1 vanos test would tell you a little more before opening up the engine, however, the DIY's on here to check cam timing are pretty easy to follow if you fancy a lazy afternoon checking the mechanicals before returning
 

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Discussion Starter · #3 ·
Was a auth BMW garage, largest in Oslo, should think they used proper tools/diagnose test.

Had the same thoughts myself. They said there where a lot of errors, but only lambda came up after reset. Don't know if they run the test on idle or during a variations of revs.

Probably will open it up and check for myself before asking for another test, don't quite trust the BMW M experience of the mechanics, and a timing/tensioner etc check is easy 1000£, better off with a cold beer in my own garage during the weekend :)
 

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- Workshop checked for error codes, only came up with faulty Lambda, which turned out to be a loose wire, some of the other lambda sensors seemed broken (loose where the cable comes out) have baught new, but not replaced yet.
You need to change those O2 sensors first and see if it helps, or at least the pre-cat ones. It's unusual to have a loose wire and it's certainly unusual for them to be loose where the cable comes out.
 

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Beyond what's said above, consider posting an audio/video recording of the sound, and/or sending member vantaam5 a message.
 

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Well, if they reset the codes, did they log what they were? If they ran them before, I would certainly wonder what they were and if any were pertinent, not just the one that came back up. I suppose I am just curious if they tested well enough and allowed for the codes to come back.
 

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Discussion Starter · #7 ·
Changed both lambda sensors yesterday, did not solve the problem. Allthough they were due for replacement, noted considerably better response in the engine after change, so not completely waste of time.

Not sure if going back to the garage for a new code check or taking both "top covers" off for inspection is the best way forward, probably the latter ?

Might post a vid tomorrow, see if any of you recognize the sound.

Anyway, thanks for input so far!
 

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If you're so inclined, and have the time, removing the valve covers could give you an early indication of possible symptoms. For starters you will be removing the plenum, which will denote any oil in you intake tract.

Once the covers are off, you will perhaps be able to view the vanos hub bolts to see if they are still secure, and even if you don't remove the timing covers (unlikely at this point) then a poke around with a good strong pen torch would allow you to view at least some of the chain guides, all of which could attribute to ticking type sounds.

Might be worth checking your main tensioner on bank 1 by removing that and at least seeing if its all still inact
 

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Discussion Starter · #9 ·
Most covers are off now, a lot of dirt in the plenum but no oil floating around.

Noticed that the main chain/timing chain is a bit loose, can move it about 5mm and enough to make a ticking noice. Is it supposed to be a little slack, or should it really tight ? Have not loosened Vanos pressure yet.
 

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I'm not 100% sure, but i know that your main tensioner in bank 1 is operated hydraulically off engine oil pressure. If the car has sat and pressure has drained from it then i suppose it could be down to the fact the tensioner is not full of oil and holding pressure.

Perhaps, it could also be attributed to the fact hthe tensioner is failing anyways, but one step at a time, as the main reason for this small teardown and check is the fct you are complaining of rough engine running which shouldn't be down to a failing tensioner.


Ideally i would be checking over vanos solenoids/orings, cam timing and a re read of codes. It seems odd at this stage that what you say sounds like misfires are not actually registering on the car in the form of codes etc.

Also remember however small an amount you can see of them, try to inspect the visible portions of the chain guides for any damage.

Perhaps with a check of the above, if all is well, if you still experience the tick noise, you could either buy a new tensioner, or do an oil change but remove the lower oil pan to do this, this will allow inspection of the pan to see if any of the hidden parts of the guides have broken off and settled in the pan before embarking on a more comprehensive stripdown
 

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What covers are off?

Where in the chain are you feeling the slack, at arrow 1 or 2 or somewhere else. Maybe post a photo.

It's common to see some slack at arrow 1 on bank 1. The tensioner tensions the lower chain run and the tension on the upper run just depends on what way the valve springs are loading the cams when the engine stops.

Auto part Engine Bicycle part Metal Gear

It is possible that pistons hitting valves 2 years ago did some deeper damage than what they repaired, like rod brgs or lifters or chains and it is showing up now.

Are you going to change the CPS's while you have it apart?

I agree with jamie - pull the lower pan to rule out serious guide damage.

If after checking all this stuff, you put it back together and it's still ticking and misfiring, please post a sound clip, and read the codes again.
 

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Discussion Starter · #12 ·
I am amazed by the knowledge and helpfullness in here! :)

Sorry about the late reply, car has been left by itself the last days (not as if it's going anywhere...)

Timing checks out fine, but when comparing your picture to mine regarding chain guides, well, something is missing :/ (see attached pictures) and the chain has made some trails in the metal part of the guide. No plastic left, guess that's in the oil pan, which i've not opened, yet. So guess I need to order and replace more than the main chain tensioner (arrives tomorrow).
 

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The plastic guide has departed from the steel backing.

Next course of action would be to strip off both vanos units, both top timing covers and the lower oil pan and bottom timing cover to inspect any other damage to the other guides.

However, if it were me, i would be doing this and replacing all guides regardless if the other 2 showed no damage, which i doubt given your tensioner rail

Malcolm, AKA 68FB has performed this and done an extensive write up for a DIY.

Looks like its time to get reading, but at least you have determined the cause
 

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Discussion Starter · #14 ·
Thanks for your quick reply!

Guess it's the only sensible thing to do at this point, as you say. Have done a lot of reading so far, so understand that I have a huge job in front of me.

Do you reccon the timing chain has been so loose that it can explain loss of power and "yerky" acceleration ? I noticed that I could move the cams quite a bit back and forward before main chain was able to start pulling the other bank.

Anyway, when I take of all the timing covers and oil pan, I should be able to inspect a lot more.

Again thanks all that have contributed so far! :)
 

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Your guide looks like mine did. I also had a performance loss below full throttle. I think the issue was the slack in the chain causes a slight timing mismatch. Definitely replace the guides at the very least but if you have the time it would be a good idea to time the engine as well. I have some references to other threads, pictures and video in my old thread. Hope this helps and GL. Let us know how it works out
http://www.m5board.com/vbulletin/e3...-thread-only-when-warm-between-2k-3k-rpm.html
 

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Oh, dear.

Here are some relevant DIY's.

http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/169099-cam-timing-diy.html

http://www.m5board.com/vbulletin/e3...k1-upper-timing-cover-my-progress-so-far.html

http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/143123-timing-chain-guide-removal-3.html

TIS is mandatory.

And remember to change your oil filter. It's storing all that worn-off aluminum.

I didn't replace any chains because my guides were still OK but think it would be a good idea for you.
 

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Discussion Starter · #17 · (Edited)
Update, finnaly removed most relevant parts and soon ready to mount the new parts when they arrive later this week. Have to order som more parts aswell (oil chain + tensioner, main chain, vanos spring plate, fan belt and some gaskets)

It's really clear that this job was needed, as you can see from the pictures below, there is quite significant amount of wear on guides, and the main chain tensioner was stuck in "closed" position, meaning no tensioning of the belt at all, as I understand it.

In addtion, tensioner on oil chain is bust too, so that chain have left marks on the block :/ On saturday, I bought a air pressure tool to make unscrewing the gadzillion number of bolts, good investment :)

Sorry for poor picture quality; couldn't find the charger for my "real" camera, so had to use the phone.

The good things:
1st bonus:Found a new water pump in my garage, think I bought it for my 540 some years ago, but did never get around to replace it, surprise, same part nr as for the M5, complete with gaskets :) so will be mounted with new pump.

Attached pictures:
2nd "Bonus", belt looked fine until I took it off, no sign of wear except the "split" odd:

Wear on the lower cover:

A lot of slack on the chain even with the guides still in place:

Wear on the oil chain, the tensioner is _really_ loose, and does barely touch the chain

Wear on the "U shaped guide"

Will take som hours before the sweet noise of this engine is heard again:


I guess I'm lucky after all, seeing the wear, It can't have been far away from a disaster.
 

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Wow, man, that pic that shows how much of the teeth are exposed on that sprocket is frightening! Glad your engine is still in one piece!
 

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I've always wondered how the main chain tensioner fails. The piston part that bears on the chain guide (opposite end to red arrow) should pop out smoothly under spring pressure. Is it stuck in the bore?

There's a spring-loaded ball that acts as an oil pressure relief valve to prevent over-tensioning the chain. You can see it looking in the small hole in the photo. Is the ball still being held down securely by the spring? If that spring fails, the tensioner leaks oil through the relief valve and wont extend to tension the chain.

Auto part Cylinder Nozzle

My oil pump chain had been hitting the chain cover and I assumed it was because the tensioner was very weak. But I found the new tensioner was hardly any better. So I assumed my chain was worn. But then jamiepeers replaced the chain and tensioner and said his chain was still almost hitting the cover. So you may not find the new chain and tensioner much of an improvement.
 
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