Chattering when cold

[the_dingman]

My engine is making a chattering noise when cold, the best description I can make is that it sounds like a diesel. Once it's warmed up only a minute or two, it stops. I've got new belts, a new timing chain and adjusted my valves, and it did not change before or after. I don't remember this from my old one, but that was years back... Any ideas?

 

[the_dingman]

No ideas?

bump...

 

[turboSR5]

Oil pressure?

Since you just replaced your chain, and used all new good quality parts...I can only assume that you have some low oil pressure in the first couple of minutes after a cold start. Might be worthwhile to peel the valve cover off and take a look at your guides and check your chain tension. While you are in there, double check your valves again, assuming the engine is warm at that point.

 

[the_dingman]

We adjusted the valves twice, and the guy who helped me is a very good mechanic who usually works on BMWs, Lambos and the like, so I very much trust his work.

As for the oil pressure, my gauge reads the same when it's cold, as well as when it's warm.

I am thinking that it may be noise from the exhaust, as I do have a small leak after the cat, but I'm still trying to pinpoint it.

 

[jdmidwest]

Are you using the correct weight oil, 5w-30? Thicker oils have to warm up and thin out to lubricate properly. Sounds like lifter noise, common on older engines on a cold start when they get some wear on them. Keep an eye on it.

 

[the_dingman]

I'm using conventional 5W-30, and I know we inspected everything under the valve cover and didn't find any problems. It's not the same kind of click that my car has with it's sticky lifter, it's a very loud chatter, like I said it sounds just like a diesel engine for the first 2-3 minutes when you accelerate.

 

[turboSR5]

Exhaust leaks can make a wide variety of sounds, it's a possibility. The sound you describe makes me think it's the classic timing chain noise, especially the fact that it goes away after a minute or two. Since your oil pressure is good at start up I guess you can rule out a slack tensioner due to low oil pressure. Even with that, and if it were me, I would take a very good look at that chain and for any evidence of wear on the new guides. Just to be positive that it is not the problem.