New noise

[x_atlas0]

Hello everyone.

First, thanks for everyone who offered to send me a rear window. Dave in NC has already done so, so hats off to him.

When driving the car to get yet another body shop estimate (#10 or so) I noticed a very pronounced and strange noise.

The noise is worse when the car is cold, but is present at all times. It sounds like a chain is being dragged on the ground when I accelerate or let off. It is difficult to tell the source, but it sounds like it is coming from the front. It occurs mostly around 30-40mph. It occurs at all RPMs in that range.

I have yet to replace the chain tensioner, so I suppose that could be it. Any other suggestions?

 

[Philip Slate]

One of the things that all M30 engines have in common is that the chain guides are prone to breakage. This can cause the chain to loose tension and rattle around and even jump teeth on the cam/crank sprockets, a potentially very bad thing. You would most likely hear the chain noise at all times if this were the case. Check the chain tensioner first, though, 'cause it's easy to do. If it's not that, then look for a chain dragging on the ground...darn kids and their stupid pranks.

 

[AndyM]

I had a screwy noise like that once -- it ended up being the big nut on the driveshaft. It came loose and clanked around at certain rpms. You may want to check that -- especially if you had recent work done in the driveline department.

 

[velocewest]

On my car, the clutch on the big York A/C compressor makes that exact noise. It isn't bad, it's a nearly new compressor and clutch, it just does that when not engaged. Or, should I say "did that" -- that boat anchor is in a box in the garage now.

 

[x_atlas0]

Thanks, everyone, for the suggestions.

I'll put the car up on the lift and poke around. I did have driveshaft work done recently, so that sounds like the culprit to me, and it would make sense as to why it happens at speed, rather than RPM. I was worried I was low on diff fluid.

Velo-no AC, so no AC compressor. Something I am attempting to rectify.

I must have gotten the least luxury coupe they made, aside from the CSL- no sunroof, no AC, cloth seats, I don't think it even had a radio.

At least it has power steering.