M42 Sounds Like a Tractor

[CJackson]

Why does my M42 sound like a tractor?

I recently pulled the M40 out of my E30 318i to swap in an M42 from an e36. The M42 was sitting around in my shed for about a year before installing it into the 318is. I am also unsure on the age/condition of the chain tensioner so that could be the problem but I'm still not sure. The engine runs on an E30 loom/ecu and I'm still using an e36 intake with the DISA valve fixed open, not that it should make a difference to the noise its making (from my knowledge). I can't pinpoint where the noise is coming from but it has to be from the head somewhere.

Below is the link to a short video of the motor running. Please excuse the stupid blue breather hose and incomplete COP.

https://youtu.be/Fn4qr17fWwk

Thanks in advance.

 

[monty23psk]

From the sound it would be your chain tensioner. If you don't know the age of it, I would replace it either way. After the engine warms up, does it go away?

[CJackson]

Righto cheers, will replace ASAP.

The sound remains when the car is warm. If it was to remain what would it be out of curiosity?

[monty23psk]

If it went away after engine was warm, then for sure it is the tensioner. It needs oil and heat to expand. If you replace and still hear, it could be something on front timing case as the guides are plastic. The fact that the car sat for a little without use can mean certain things are dried out, like the tensioner. The cam lifters would be another area to check.

[CJackson]

Thanks heaps for your help.

[pless]

Did you ever found the cause of this problem. My m42 sounds exactly the same... wondering if you have a solution before I start investigating on my side.