Noise--please tell me it's not serious!

volvo
exhaustsystems
noises

#1

I’ve been avoiding a trip to the mechanic because I don’t want to be told that my 1988 Volvo GL needs yet another repair. When the car is running, I hear a noise like something metal vibrating, as if a piece is missing somewhere or even like a hubcap is loose (but that doesn’t seem to be the problem). I’m completely clueless when it comes to cars. Could it be something as easy as a muffler or exhaust part? I’d appreciate any insight into this! Thanks!


#2

need lots more details. Does the sound occur when the car is idling, or just when it is moving. Does it change as you go faster, or as you increase engine RPMs? Does it seem to come from the front or rear of the car?


#3

It occurs when the car is idling and moving. It doesn’t change. It seems to be coming from the front passenger side.


#4

Take off the hub cap on the front passenger’s side and see if all the nuts are on the studs that hold the wheel onto the hubs. You can use the pry bar end of the jack lever in the trunk to do this. Then you might open the hood and see if anything metal is loose. Be sure that the engine is off when you do this (you said you are clueless). Find the drive belt and push/pull on the pulleys it rolls over. You are looking for a loose pulley. What about the brackets? once again, push and pull to make sure that everything is tight. The suspension is on the underside of the car. If you are feeling adventurous, turn the steering wheel fully to one side. Then look at the suspension parts you can see on both sides. Again, push and pull to see if anything is loose. Turn the steering wheel fully to the other side and repeat. If you have a friend or two who know something about cars you might invite them over to help you.


#5

so with the car in neutral, if you step on the gas, the sound does NOT change? odd!


#6

What you might be hearing is a loose heat shield.

The exhaust system has various thin metal parts called heat shields. These can be welded, crimped, or clamped to the exhaust system. If one breaks from the exhaust system, it can cause all sorts of noises.

You just need to bring it to a muffler shop and ask if they can locate a loose heat shield.

Tester


#7

If the rattle is indeed from a loose heat shield, then it is not serious. You can even ignore it until the next time your car needs to go on the rack. But one never knows, does one? You would like to know. Try poking under the parked and idling car with a broomstick. See if there’s anything you can do to quell the noise.


#8

If the sound does not change with speed or rpm, it could be in the ventilation fan. I know this seems rather simple, but I’ve seen it happen. good luck.


#9

I like this one. It would be so easy to diagnose if you could hear it…

But it stops if you turn off the fan, kinda obvious test. Chicago skater, check this and let us know.

Actually, for some cars the fan is always on at low speed. So Chicago skater turn the fan speed up and see if it changes.


#10

hope they let us know when they find it. Could be almost anything. I too thought the test would be obvious. Just turn on the key…


#11

Thank you for all the feedback! I will definitely let you know when I figure it out! --Elizabeth


#12

Noises are often difficult to diagnose even when you think that you know what you are doing and it’s your own car right there in front of you. Have someone with a gloved hand push the exhaust tailpipe to one side and the other to see if it affects the noise.


#13

Exactly. I have to go with the loose heat shield too.
The vehicle doesn’t need to be running to check this out.

Simply shake the exhaust pipe.


#14

If it does turn out to be a loose heat shield, it can be secured with a large worm-type hose clamp from the hardware store. That’s a permanent fix that works for under $2 in parts.