Noise

[kknobl]

All,

 

When the car is running and in Park, every once in a while, I'll hear what sounds to be a almost a grinding rattle (very difficult to describe) coming from somewhere in the engine bay.

 

The car runs fine, and this only seems to happen when one of the cooling fans turns on. It will also do it when I first start the car up and accelerate up until it hits 2k RPM. It seems to stop at anything past 2k RPM and the noise seems to stop after a while.

 

I'm thinking one of the belts might be going...Any thoughts?

 

Thanks,

Kevin

[3pt1lumina]

maybe a pulley is starting to go? .. whats the car/motor?

[Supreme Cutlass]

Might take a look at the tensioner too. Using a long, large screwdriver is a cheap substitute for a mechanic's stethoscope to help you pinpoint the noise.

[kknobl]

maybe a pulley is starting to go? .. whats the car/motor?

 

Forgot to include motor info - 3.1 MPFI - 93 Grand Prix. It sounds as if the noise is coming from near the Power Steering fluid fill.

 

Thanks!

 

Kevin

[Supreme Cutlass]

Look very carefully to see if you see anything vibrating that's attached to the S-Belt. My guess is still the tensioner.

[kknobl]

Thanks for the feedback.

 

Assuming for a minute that it is in fact the tensioner, in your opinion, is it urgent that I get it fixed right away (I don't do that much driving with the car)? Would the car be OK on, let's say, a 60 mile round trip (mostly highway)?

 

I'll get it fixed, don't misunderstand me, but I'd like to hold off on it for a month or so.

 

Let me know your thoughts!

 

Thanks,

Kevin

[Supreme Cutlass]

It would be fine in my mind, but you might wat to wait for more experienced advice just to be sure. It's kind of hard to judge where that sound is coming from, ( I forgot to mention that I think I have the same problem) as there are so many places it could be, and it's almost impossible to tell without a stethoscope. But since it's only in park, and doesn't get louder as the engine speed increases. I wouldn't think it's that serious.

[DaveFromColorado]

ya know, someone was just asking about their timing chain - that's one of the noises you can expect to hear, and under the same kinds of conditions - I'm sure it's not beacuse the fan came on that you hear the noise, but more of the load on the engine from the alternator turning the fan that causes the slack in the chain to rattle.

 

I had an 88 Buick Regal that went through 3 timing sets before I got one that wasn't super noisey and cause all sorts of timing cover slapping issues.

 

--Dave.

[kknobl]

ya know, someone was just asking about their timing chain - that's one of the noises you can expect to hear, and under the same kinds of conditions - I'm sure it's not beacuse the fan came on that you hear the noise, but more of the load on the engine from the alternator turning the fan that causes the slack in the chain to rattle.

 

I had an 88 Buick Regal that went through 3 timing sets before I got one that wasn't super noisey and cause all sorts of timing cover slapping issues.

 

--Dave.

 

I had given some thought to the idea that it might be a timing belt/chain (not sure which the 3.1 has) but it doesn't stay constant, plus the engine seems to run fine - no misses or anything like that. I've heard Saturns where timing chains have become loose and there is a constant noise, even in higher engine speeds.

 

Kevin

[kknobl]

It would be fine in my mind, but you might wat to wait for more experienced advice just to be sure. It's kind of hard to judge where that sound is coming from, ( I forgot to mention that I think I have the same problem) as there are so many places it could be, and it's almost impossible to tell without a stethoscope. But since it's only in park, and doesn't get louder as the engine speed increases. I wouldn't think it's that serious.

 

Thanks for the advice. I wasn't thinking it was the type of thing that needed to be addressed right away, for the simple fact that the noise doesn't get worse as the engine revs past 1.5k RPM and in fact goes away. Plus its an intermittent noise and not a constant and the car runs fine.

 

Thanks,

Kevin

[Supreme Cutlass]

There's a pretty good chance Dave is right though. My timing chain is very suspectable to be worn. I've been doing alot of research on it lately, after all, I was the one who wrote that post You have to remove most of the belt driven acessories, so it's a PITA to even check. If you're going to fix it in a month, I wouldn't worry about it now, but as I said that's just my personal opinion. If you could I would inspect it ASAP at a qualified repair shop and see if they can tell what it is. If you have to replace the chain, It'll be cheaper to replace now (especially if you are a do-it-yourselfer) than if it goes while you are on the road-- then you'll be worrying about towing, probably bent valves, etc.

[DaveFromColorado]

The reason the Saturns, and pretty much all the Quad-4 engines, the ford 4.6 single, and dual over head cam engines, and the 5.4 engines are so noisey (sounds like a power-steering whine) when the chain is startin' to die is because the chains are SO long, on the 3.1 that you have (which does have a timing chain) there's not a whole lot of room for it to build up the vibration to create the type of noise you may expect from something like a saturn.

 

Anyhow, when the timing chain gets a little sloppy, you usually won't notice much difference in power, or in the way it runs, after all, it's only losing, and picking up a few degrees of timing with every revolution, but if you change the timing set, you may feel the car being a bit faster, and better gas milage, but nothing beyond maybe 1 or 2 MPG, and 5 - 10 (flywheel) horsepower.

 

--Dave.

[kknobl]

Thanks for all the feedback. Any idea how much the timing set would cost - I'm not really a do-it yourselfer so I would be taking it to someone. Any ballpark figures would be great.

 

Also, if anyone is from the Levittown/Langhorne area of PA, and know a good trustworthy mechanic, please let me know.

 

Thanks!

 

Kevin