Knocking,tapping,clanking sound coming from motor. Increases with higher rpm

Title pretty much says it all, here’s some finer details.

The car is a 1997 pontiac sunfire 4 cyl 2.4L.
When the car is turned on it makes a sound like the one in the mp3 file that I’ve attached. Some other symptoms I’ve noticed is a very slight loss of power while accelerating, and whenever I pull up to a stop and the engine gets into the idle rpm range (800-1000) the oil light comes on and the rpm dips to about 400 and sometimes the engine dies. The engine is also running very very hot, although I haven’t driven the car in about 2 months and it’s 100 degrees outside, not sure if that’s related.

What I have tried so far is replacing the oil and filter, and adding 2/5 a pint of seafoam engine additive for 4 quarts of oil as per the instructions on the bottle. I did this because I suspected it was a stuck lifter, but after driving it for 30 miles with no improvement I’m starting to think otherwise.

As some of you may know I’m not entirely mechanically inclined and that’s why I’m here, sometimes I get posts from people who insist I shouldn’t be anywhere near an engine but let’s try to keep those negative posts off my thread.

You need to have someone to remove the valve cover and check to see if something is amiss in the valve train.

Something like a loose rocker arm, broken valve spring, or a bent push rod.


it s hard to be positive about the symptoms you ve described. I don’t know how to open anMP3 file but… it sounds bad from your description.

on the bright side, you have all of us to help you keep your new car in better shape.

@wesw just double click on MP3 then click on “open” to hear the noise. @Tester hit the nail on the head.

I’m putting my money on bottom end. Spun rod bearing.

When you say the engine is “running very, very hot”, do you mean the temp gauge is all the way into the danger zone? Severely overheating could well be what caused the damage to your engine, and even if the mechanical noise proves fixable, if you’ve overheated the engine several times, it’s likely the whole thing is cooked.

Between the noise, the oil light coming on, and the overheating, If the car is worth keeping, I see a salvage yard engine in your future.

I am usually in agreement with Tester, but–like PvtPublic–I think that this ominous noise is more likely to be coming from the bottom end of the engine. A rod bearing or a main bearing are the possibilities as I see it.

Instead of revving the engine, I would suggest that the OP have the car towed to an indy mechanic’s shop in order to have the oil pan dropped and the bottom end inspected. For the OP’s sake, I hope that I am wrong, but I believe that the inspection will find a badly-worn engine that is beyond any additives, and that is ready for automotive heaven.

The age of the car precludes rebuilding the engine, but there should be boneyard engines available–if the condition of the transmission and the body/chassis warrant spending any money on repairing the car.

Make mine another vote for the engine’s bottom end being the source of the noises.