I have a 1995 Bonneville SSEi. yesterday it started making this rattling noise. It'* coming from under the hood. I don't hear it while I'm driving but when I come to a stop the rattling starts. I checked my oil and I was a qt low so I put a qt in. Can anyone give me any info about this?

Check the harmonic balancer.

How is the oil pressure when the car is warmed up and in park?
If it'* super low then you are most likely losing a bearing in the bottom end and should either consider having bearings put in/crank checked or aim toward another motor.

If the pressure is not in the red say 15+psi then pull off the belt for the supercharger and turn it back and forth quickly. Do you feel play or is it solidly connected? Play is usually a supercharger coupler. ZZperformance.com it'* $30 and get two bottles of SC oil. I believe there is a write up in techinfo.

If you have no slop, crawl under and look for cracks in the harmonic balancer rubber. Usually this will make your car run horribly, something you didn't mention.

First guess would be SC coupler though.

With a cold car, not running, pull on each belt in the direction of rotation or opposite. Do you see your Crank Pulley (harmonic balancer with two belt paths) moving at all? If so, change it. If not, remove the SC belt and turn the pulley on the supercharger back and forth. Do you feel slop or wobble? If so, change the coupler. Start a new topic in Forced Induction if that'* the case.

I hope I don't have to buy an engine. I bought this car last october and two weeks after I had it the engine went out. Warranty company replaced the engine it had 56,000 miles on it when they put it in. The original engine had 86,000 miles. Hopefully my warranty is still good.

I'm sure glad I found this web site have some other question to ask about my car

Thanks

HenOra

You don't have to change your engine. Please read our advice and let us know what you find. Your odds are 95% it'* either the harmonic balancer or supercharger coupler.