P0011 Code 2001 X5 4.4 M62 V8 -New Owner-

[lebowski9]

Originally Posted by andrewwynn

I have a theory on the guides after replacing on two M62tu: they are very brittle after time so they only need some impact to cause the initial shatter.

The chain is in more or less a large "V" doubled over and the upper V part is guided around the water pump by the chain guide. If the chain is not held tight you just need a combination of off throttle to slack the chain and hit a bump, the chain will come off the chain guide from momentum and then snap back up into the brittle plastic chain guide and shatter.

Probably the most important factor to avoid this is periodic replacement of the chain tensioner. Second, regular oil changes to make sure the viscosity is correct to build the right pressure in the chain tensioner.

Don't know what the proper replacement schedule is but "less than 160,000" for sure. I've found recommended 100,000 mile replace interval but not official BMW. I'm quite confident based on some M62 over 200,000 miles on original guides and the case above less than 100,000 that the tensioner is a huge deal at preventive maintenance to keep your guides from self destuction.

If I had an M62 motor with over 100,000 miles I would buy a new OE/OEM chain tensioner literally today I wouldn't wait one day.

@OP: if I think you may have stumbled into saving your guides by accident.

If your codes return the next thing is either CPS or vanos. You would need to plot a graph like I did above to compare the requested vs actual cam position. If the vanos seals have worn enough they can't keep up or hold steady.

The first M62 I redid the guides, I got the same codes and it was just the CPS in my case.

I would definitely get a scan of the graph of your cam position so you know more info. Eg worn vanos but not enough to set MIL.

Interesting, If I do keep it I will look into getting a laptop with INPA.

About the oil, would a higher or lower viscosity prolong the guides?

Two schools of thought, higher viscosity could provide more "cushion" and keep the pressure up

On the other hand, heavier oil might take too long to build pressure in the tensioner?

I have Semi-syn high-mileage 10w-40 in there. I figured it would hold pressure between the vanos seals better if they are worn as well as protect the plastic guides. Part of me also thinks the lower weight oils were spec'd for fuel economy/ environmental reasons...