Very noisy engine at idle Rattles like cam chain. Noise goes away as you rev the engine. What do you think it could be?

SOURCE: 1989 Dodge Raider timing chain worn out

I doubt it is the timing chain. More than likely it is the valves themselves, the seats wear out, and the lifters wear, so eventually the lifters don't pump up as full as they should, so it causes a gap between it and the valve, so it slaps the valve, also the seats wear, so the valve is kinda loose, so that causes a gap between it and the rocker shaft, so you get another slap. If the chain wore out enough to be hitting the block or front cover, you would be having timing issues because it would have to be pretty loose. You may also have a failing oil pump, so it is not suppling the right pressure, which is why you hear it at idle, because under load the pressure goes up and as I said it pumps up the lifter. This guy is a joke if he told you just to drive it till it blows, which would cause significant damage, Then you have to buy a what? use motor for $600 that is no better off than what you got? Then pay someone like this idiot $500 to install it? Right now you could probably rebuild the engine for about $600, and have a brand new fresh motor for your truck. The chain is not too difficult, you can do it in the car, but would be much easier out of it. The head doesn't have to be removed to do it, but you do have to take off the timing cover, which can be a pain, and possibly the water pump, all the engine pulleys, alternator, etc. So thats why I suggested pulling the motor. And, when it is pulled, it would be a great time to freshin it up with new pistons, rings, bearings, have the block done and rebuild the head.

SOURCE: mazda cx7 engine noise

Does the engine have hydraulic lifters? If so air can get into the chamber under the lifter and cause lifter noise.

Diagnosis and repair requires removing the Valve Cover. A fairly easy job for your local shop.

SOURCE: engine noise

Could be chain slack until it warms up. Check your tensioner, and possibly needs valve adjustment if it hasn't been done. On a worse note, could be oil pump taking time to get oil to the top end.

ROBERT GARCIA

• 926 Answers
• Posted on Apr 20, 2009

SOURCE: Nissan Timing Chain still rattling

and the lower chain guides?

SOURCE: noise in trans or in primary chain

It sounds like the primary drive chain is loose. The way I adjust mine is to take off the upper left inspection cover, start the bike and slowly tighten the adjuster until it starts to wine, then back off until it stops. Rev it slowly and listen for a wine. No wine good to go.