Mystery Grinding Noise

cavalier
chevrolet

#1

I have a 1998 Cavalier (147,000 miles) that has made a ticking noise when I start it. However, revving the engine will quiet the noise before driving. Recently, it began making a extremely loud grinding noise when starting, that too will quiet when the engine is revved, but comes back when I accelerate. It does not lose power when I accelerate, but it feels horrible.


#2

New, strange car noises should always be investigated promptly, lest they become expensive repair issues.

While the “ticking” noise that you describe is likely to be sticky valve lifters, I would strongly suggest that you stop revving the engine when it is cold. The usual cause of sticky valve lifters is a build-up of varnish, dirt, and sludge from oil changes that are not done frequently enough. The build-up of these deposits leads to lubrication problems such as sticking valves lifters, but it can also lead to MUCH more serious issues. By revving the engine when it is cold, you are drastically increasing the odds of causing problems since the cold oil is not yet circulating properly in the engine.

The grinding noise could be something as simple as a loose heat shield on the exhaust system, or it could be something much more serious, such as engine-related issues resulting from the likely sludge in the engine and from your practice of revving your lubrication-starved cold engine.

I strongly suggest that you get the car to a qualified mechanic sooner, rather than later, if you want to limit your potential repair expenses.


#3

Thank you so much for your help.

OK, that makes sense. I keep up with the oil changes, however I have only had the car for three years and it made the noise when I got it, so who knows. Being that my funds are limited, I had my friends father, who has been a certified mechanic for longer than I have been alive, look at it and he said it doesn’t seem to be coming from the engine but also had no idea of what it could be. Is there a way to clean the sticky valve lifters?


#4

are you sure that this engine even has lifters? Most engines since the early 90s do not. But you will get a clicking noise with loosely adjusted valves on an OHC engine too, but not as a result of varnish buidup, rather as a result of wear from revving it cold, with no oil on the cam lobes. The grinding sound could be any number of things from a starter stuck in the throw out position, to a bad wheel bearing or other bearing such as alternator, water pump, a/c compressor, power steering etc. Or if not from the engine, a transmission bearing, even a u-joint can rumble when failing.