P0011 Code 2001 X5 4.4 M62 V8 -New Owner-

[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.

[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...

[andrewwynn]

All "theories" wrong. Stick with recommended oil. I heard that Mobil 1 recently reformulated, I would possibly switch to Castroil as BMW recommends but I can buy 6 pack of quarts for $28 of Mob 1 so I think I'll stick with that.

The lifters and chain tensioner use oil pressure to function. Some motors like n52 are very sensitive and require a good half hour to get the lifters working properly.

Full synthetic only on BMW motors. You can easily get 7000 miles per change. I change when the computer countdown tells me it's a very reasonable based on liter consumed formula. No chance of getting 200,000 on conventional oil.

I've used oil we took out of a car for the initial break in after replacing guides but maybe 200 miles then full change to get any engine open to the would gunk out of there.

[andrewwynn]

Oil is injected onto the guides under the chain. All that matters is it's slippery and it will do its job. The different viscosity will only change the thickness of that layer a little. If it's 0.003 or 0.005" layer will make no difference.

My conclusion is the most important factor for the chain guide longevity is the main tensioner


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[lebowski9]

Okay, the service engine light came back after about 6 start cycles. Now I have a code P0340! Does this mean it was the sensor after all?

[andrewwynn]

Best thing in rooting out problems is when after you've changed a part the error changes. But yes as initially suspected cam sensor is the primary suspect when anything cam timing related is involved.

It's very rare to actually see the unicorn DTC you reported, the problem is the computer trusts the reading from the sensor and usually the sensor outputs something just at end of life it's no longer and accurate value so the computer is convinced the cam is over or under advanced.

I've never seen a failed CPS error in the wild, always have to sleuth out if it's the cause.

I bought my car with SES lit and random errors having nothing to do with CPS. Google search brought me to xoutpost where somebody mentioned replace CPS and it fixed their problem and it worked for me.

Wife's car was about 15,000 miles younger and sure enough a year after my CPS needed replacing so did hers.

I would expect faikure around 4000 hours; divide your odometer by your average speed. You said an older guy was the previous owner; if he drove a lot of city miles that would make sense. (Failure at earlier if clock)


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[lebowski9]

Alright I have an update. After re-replacing the timing chain tensioner, I attempted to prime the tensioner by cranking the engine with the fuel pump relay fuse removed. Sure enough it wouldn't start.

After replacing the fuse it started and rattled briefly and returned to its quiet operation. Took her out for a 5 min spin and upon returning I was greeted by a horrible loud knocking sound at idle.

The sound seems to go away above 1.5-2k rpm and the vehicle performs normally. No codes.

I cycled the vehicle on-off about 7 times to see if any codes would appear.

So, with the rest of the thread in mind, where does this take me now? VANOS or timing guides??

See link for video of my engine: https://www.youtube.com/watch?v=ZeMMedwZlyY

[lebowski9]

Ok. Found out the problem was the timing chain tensioner--it did not decompress or pump up ! This was due to my incorrect compression and use of locking ring.

The newer design tensioner has 3 grooves as opposed to just 1 and it isn't exactly intuitive which way the clip goes; I slid it up instead of down, nearly permanently locking the tensioner together! OUCH!

After reassembly it runs quiet as ever, but the question now is did I just hasten the demise of the timing guides ? That horrible racket was indeed the timing chain slapping the guides..I even drove it around the neighborhood...Makes me wonder if failure is no imminent.

[andrewwynn]

The only way to determine is if there are bits of plastic in the oil pan. You can use a boroscope up the oil level sensor hole but you can get a fair look through the oil fill hole. If it survived the short drive it likely hasn't shortened the lifespan much.

That said were it my car I would replace the refund my tensioner with an OEM brand now that I determined it's almost certainly the actual cause of the typical failure of the guides


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[lebowski9]

Thanks guys. She runs beautifully now.