N62 misfire

[murmansken]

Well seems like the guide has snapped or a chunk came loose from it. Look at the tensioner it´s on the backside of the guide therefor it was possible for it to chew threw the solenoid. Interesting fault acctually. This could have been a lot worse with broken valves and severe damage on pistons.

[andrewwynn]

Wow I was prepared to see much much worse. Looks very recoverable.



I was surprised to see any of part #7 at all.



Looking at the reference photos looks like you just had the ala M62 chain guide self destruct where the plastic shoe portion shattered and went into the oil sump.

I would be willing to bet the tensioner was the cause though.

Do you know if the tensioner was replaced with the chain/guides? Havimg done a couple guide replacements, I'm betting if you aren't changing the chain you could probably change the guides without redoing the timing. (if vanos left cogged to the chain you shouldn't need to re-set the timing) just thinking out loud.

Keep posting I'm rooting for you I am quite sure you caught this just in time to save the engine and it's not a huge fix from this point.

[murmansken]

Originally Posted by andrewwynn

Wow I was prepared to see much much worse. Looks very recoverable.



I was surprised to see any of part #7 at all.



Looking at the reference photos looks like you just had the ala M62 chain guide self destruct where the plastic shoe portion shattered and went into the oil sump.

I would be willing to bet the tensioner was the cause though.

Do you know if the tensioner was replaced with the chain/guides? Havimg done a couple guide replacements, I'm betting if you aren't changing the chain you could probably change the guides without redoing the timing. (if vanos left cogged to the chain you shouldn't need to re-set the timing) just thinking out loud.

Keep posting I'm rooting for you I am quite sure you caught this just in time to save the engine and it's not a huge fix from this point.

Well I think I need to change the chains and guides and tensioners, i guess I have to redo the timing to. I have the tools so not a big problem.

[murmansken]

Finally I have some stuff loose to see what has happened on drivers side I actually found the piece that was missing and im wondering if I could have broken it when I took the valve cover apart.

On the passenger side the timing chain seems to have streched. Propably faulty tensioners to and has started to chew about 1 mm on the solenoid not that much but enough make me wonder if there has been cheep china shit chains in this beamer. Both tensioners are bmw oem. I don´t know if they changed the tensioners but the spring in them has verry little pressure.

Im taking down the oil pan another day and has to do a pick list of parts I could need. Did a leakdown and I dont have any bent valves, but it was hard do do because the timing is a bit off...

I sure as hell caught this just in time.

[JeffC]

In your pic above, the alternator bracket is in place. Don't you have to remove it to get the cover off?

That looks like a lot of chain stretching.

[murmansken]

Originally Posted by JeffC

In your pic above, the alternator bracket is in place. Don't you have to remove it to get the cover off?

That looks like a lot of chain stretching.

The alternator bracket is loose had to pry it a little to get the chaincover loose. But you need to dissasemble subframe & front diff to remove the oil pan. Yes the chains are stretched a lot. Had a huge amount of luck that the valves didnt get bent.

[JeffC]

OK. So you do have to loosen the front diff and release the bolts on the side of the engine mount bracket. I was hoping you found a better trick

FYI.
The old timing guide have been superseded by newer and longer ones on CYL5-8. So is the lower plastic one in CYL1-4.

I am wondering if the "stretch" is because the material that the chain is sliding on has broken off or is it really the chain.

Also saw the the lower timing guide on CYL5-8 has its tip broken off. This is the 4th N62 with the old style timing guide I've seen that has the tip broken off.

Removing and replacing guides on CYL1-4 is a pain as they do not fit without surgery.

[murmansken]

Originally Posted by JeffC

OK. So you do have to loosen the front diff and release the bolts on the side of the engine mount bracket. I was hoping you found a better trick

FYI.
The old timing guide have been superseded by newer and longer ones on CYL5-8. So is the lower plastic one in CYL1-4.

I am wondering if the "stretch" is because the material that the chain is sliding on has broken off or is it really the chain.

Also saw the the lower timing guide on CYL5-8 has its tip broken off. This is the 4th N62 with the old style timing guide I've seen that has the tip broken off.

Removing and replacing guides on CYL1-4 is a pain as they do not fit without surgery.

I did find a better trick Removed all bolts except one, the one behind the front diff I released until it touched the diff then I gently pryed the alternator bracked a bit to get the cover out. Going to change both timing chains guides and tensioners. I have found more plastic pieces in the oil pan probably from a previous breakdown. It´s a serious amount of work to do on this v8:s... If I ever do this again im pulling the engine out. Or atleast remove the subframe directly.

[JeffC]

Since you are this far deep into this teardown, if they have not been changed before, I would suggest you consider changing the alternator bracket gasket (12317507808) and the coolant pipe (11141439975).

After all this, you'll have a bullet proof X5.

[EODguy]

Originally Posted by JeffC

Since you are this far deep into this teardown, if they have not been changed before, I would suggest you consider changing the alternator bracket gasket (12317507808) and the coolant pipe (11141439975).



After all this, you'll have a bullet proof X5.

+1
Great idea to do now.

Enjoy that mouse eared bastard, I did

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