I want a quiet engine!

[mamzak]

Alright...my M42 is in great health, pulls hard and strong, never had an issue, but it has the classic valve tick at idle. Sounds like a diesel (not that loud, but you get the idea...)

What does it take to make it run as quiet as it did brand new from the factory? Just a valve adjustment?

[SpoolnDaapex]

m42 has hydraulic lifters so no need to adjust the valves.

Chances are its the plastic timing chain guides. Do a search its well documented. And i'd recommend not driving it until you get it fixed.

[Dj Buttchug]

timing guides... pull your oil pan and check for black pieces of plastic. run a bit thicker oil.
15/40 20/50

[Eecen]

m42 has hydraulic lifters so no need to adjust the valves.

Chances are its the plastic timing chain guides. Do a search its well documented. And i'd recommend not driving it until you get it fixed.

I thought the tell tale rattle was at like 3k rpm?


Noisy at idle is probably just aging tappets. You could replace them, but I don't think its crucial. Besides, its a noisy engine to begin with.

[///digitalme]

the m42 engine is loud...my m42 was louder, i changed the oil to 5w30 and
my iddle is alot smoother, i was told to use 5w30 on the m42 engine..but first thing is first like someone posted check your oil pan for bits of plastic...

[SpoolnDaapex]

I thought the tell tale rattle was at like 3k rpm?


Noisy at idle is probably just aging tappets. You could replace them, but I don't think its crucial. Besides, its a noisy engine to begin with.

tbh, I'm not sure. I haven't read into it much, i just know its common.

[mamzak]

It's not a bad noise at all...not like a really noticeable tick or anything, just loud. Was the M42 ever a quiet engine, even brand new from the factory? I just replaced the oil pan, and timing chain tensioner. I guess it's just natural M42 noise then?

[KenC]

Might be the chain tensioner.

[vegaskyle]

I'd be worried about the chain guides. I think M42 is just loud, but it should be a good loud not making ticking or knocking noises.

[KenC]

Post a video.

[quillbro]

Keep us up to date, id like to know what happens.

[M42Technik]

I'm currently having similar symptoms, didn't want to start another thread. Just recently started running rough from idle to 2,200 then seems to smooth out. From reading here and there I gathered its usually the chain tensioner if it is at lower RPM's. New timing chain tensioner is on the way, but I'm gearing up to replace the guide rails, it sounds like a diesel. I'll post a video soon...

[gearheadE30]

Running rough sounds like a completely different problem, although I could see blown guides causing it.

My car doesn't sound like a diesel, but it does tick rather loudly, almost like a rattle. I just replaced the chain/tensioner/gears/guides about 40k miles ago, so that shouldn't be it. I think it may be lifter noise, and some of it is just that this is an inherently loud engine. Modern engines don't sound this way because they are covered in layers of acoustic plastic, so you don't hear the mechanical noise. Granted, if it is really bad, or if the car is running rough, you have a problem.

[G-Man]

My M42 timing chain tensioner failed at 129K and my engine suddenly became good for only a boat anchor. The new timing chain tensioner is a M44 tensioner if I'm not mistaken.

G-Man

[M42Technik]

Running rough sounds like a completely different problem, although I could see blown guides causing it.

Well it was running quite smoothly until this, now it sounds like a diesel. Anyways hopefully the new one will arrive soon as I don't have another car and I need to get to work, though it is only 3 miles away. I'm just praying its rectified with a new tensioner, rather than being a more serious problem.

Here is a soundclip, this was after warming it up a bit. You can hear where the rattle or noise dissipates at 2200-2400, when the revs are coming down:

Soundclip