Timing Chain Tensioner

[jaredmac11]

I really think something was wrong with that chain tensioner.

[Nairb]

I have replaced 3 chain tensioners on my M42's. I have never replaced them "compressed." I have always "opened" the tensioner to an uncompressed state, and then simply tightened it into place. Start the engine, slight rev to 3k-4k and it's golden. I honestly never experienced any chain-slapping noise after replacing the tensioner in this way.

This is probably one of the easiest maintenance things to do on the m42, other than replacing an air filter.

[ibatic1]

The reason the tools broke was because on the socket wrenches i was using had the adjustment on the top which was where i was pressing on the wrench to create leverage to get that sucker in there. The new one i bought has it lower and it did end up taking me about 10 min to get it on with the new wrench.

[Powling]

BMW built the engine, I'd say their recommended method is in the acceptable category.

Any method that involves breaking tools I'd say is in the unacceptable category.

But you shouldn't need to break tools with either method. Everyone I've talked to that did it with the spring uncompressed said it was a breeze and was done in no time.

[e30davie]

BMW built the engine, I'd say their recommended method is in the acceptable category.

Any method that involves breaking tools I'd say is in the unacceptable category.

[ibatic1]

I put a socket wrench with a 19mm socket on it then used a big ass 22mm wrench to create leverage on the socket against the rack that holds the washer fluid. The pressure from pushing on the socket wrench broke the paws in the socket wrench. I went and got a better socket wrench and one of the big 19mm wrench that ratchets and knocked it out about 15 min later. Honestly not sure why it took me so long. Originally I thought it would take about 10 min.

[jdt10768]

I installed uncompressed and revved, no issues

[bmwman91]

As much as it is more difficult to install uncompressed, it is absolutely the right way to do it. I cannot believe that BMW thought it was a good idea to let the chain whip around until it popped the thing open after installation!

Also, how in earth did you break 2 socket wrenches?

[Powling]

Odd that it took you 3 hours to do it, I did mine in 15 minutes. Mine came compressed but I uncompressed it on purpose before installing because the other method made me nervous with the revving to activate the spring.

[ibatic1]

I installed a new tensioner from ECS and it took me about 3 hours to find the right tools to get it threaded on while compressing the spring since mine came uncompressed. I also broke 2 socket wrenches. By far the best maintenance I have done on a my m42 in a while. Very noticeable difference. My car runs like it came off the showroom floor. This should be changed on every car that doesn't show records of it being replaced.