M62TU timing chain tensioner - which is best?

[andrewwynn]

Originally Posted by Squiggy

Thanks for the clarification. 8mm longer? Wow. I'd wager that is enough to be fairly significant.

Well within the capability of the tensioner but on the 62 with one chain that should be enough to cause a slight difference in bank one vs. two in valve timing.

Vanos should be able to account for intake variation but exhaust timing is set by the chain length so there might have been a 1-2° difference in the exhaust valves timing after 160,000 miles.

The N62 not only has two chains, and far more robust guides, also four vanos so it can adapt to the requested valve timing and account for some chain stretch.

[Squiggy]

As promised, photos of the size difference between the M54 tensioner spring (left) and M62 tensioner spring (right). The M54 spring is a beast but it does actually fit inside the M62 tensioner. However, if people are really putting M54 springs in their M62 tensioners they must be cutting the M54 springs down to make them shorter. The M54 spring is very long, but also very strong. By comparison the M62 spring is an extremely weak spring.

[syncrocrick]

Well I need to replaced mine. 183000 miles and I am pretty sure everything is original. I do have a rattle at start sometimes, and another rattle at idling - also not always there.

At this point I fully expect to have to do the guides in the near future, but if I can last a bit longer that would be great.

btw - no way I would put that M54 spring, that seems like suicide.

[aureliusmax]

A solution I didn't hear anyone discuss was a prime button circuit. This would crank the engine but not deliver power to the fuel pump. Once a reasonable amount of pressure is built, an oil pressure switch is triggered which then enables the fuel pump, starting the engine. Therefore, oil pressure can be built up and produced before starting the engine, so one can never get a chain rattle or dry oil filter cartridge. This is the same theory used in larger industrial diesel engines.

[andrewwynn]

That engines can make it to 300-400,000 or more without the additional harware with more things to break is certainly the why.

A little startup rattle is not the cause of damage just a sign that the tensioner is failing. When the engine is under power and the tensioner doesn't provide enough tension is when the problem actually happens.

[andrewwynn]

Originally Posted by syncrocrick

Well I need to replaced mine. 183000 miles and I am pretty sure everything is original. I do have a rattle at start sometimes, and another rattle at idling - also not always there.

At this point I fully expect to have to do the guides in the near future, but if I can last a bit longer that would be great.

btw - no way I would put that M54 spring, that seems like suicide.

Replace your tensioner immediately if not sooner. I've seen examples of M62 > 300,000 mi. on original guides if the tensioner was replaced often enough.

OEM only and new crush washer is required.