When my car is idle at stop lights(but engine is running) I can hear a loud whinning noise. It's not coming from the engine, it sounds like it is coming from the bottom of the car right before the engine compartment. It stops whining when I give it gas, so only when it's idle. Any ideas what this could be?

 

bad U-joint?

 

Near the fuel pump?

 

Naw, I beleive the fuel pump is in the back. This is coming more from the area where the u joint is...maybe more towards the front a little. I had the rubber ring replaced that holds the drive shaft because the old one was bad. I thought that was the problem but the noise didn't go away, instead it seems a little worse now.

 

i had a u-joint go bad on my wagon that sounded the same way....

 

I thought the car was stopped hence not the u-joint. Is it an auto?

 

Yes, you are right.... this happens when the car is idle. For instance, at a red light the sound will be there. Then when I start driving off the sound will go away. Here's a better break down of the symptoms:

1) Sound will be there but will disappear instantly if I place the car in park.
2) Sound will not start when I first/initially place it in drive
3) Sound will be there after driving a little and stopped to a red light(car being idle)
4) Sound will disappear instantly after I start driving again or if I give the car gas
5) Whining is very loud and can be heard from inside the car.

 

Hmm...not sure what the flex joint does. I have to work 7 days straight before I get a day off. Will I be hurting anything(or the transmission) driving it like this? If the u joint breaks will it cause me to wreck? Is this something that is hard to see if it bad? Because I am surprised the mechanic didn't notice when he replaced the rubber ring that holds the drive shaft.

 

Maybe someone can explain how the u-joint could be making noise when the car (and the wheels, and the drive line) is not moving.

The noise is coming from the transmission. Maybe thats the problem?

 

dman777....

I have an '88 245 (auto) that makes the same noise. Sounds like a jet taxiing down a runway. I suspect the u-joint or a coupling in the trans? Trans shifts fine and car runs great otherwise.

After I come to a complete stop, sometimes the sound "spools down" to a lower tone before stopping altogether. It does sound like something is rotating freely, but I'm unsure as to what it is.

I'll post back if I narrow it down further....

cmoore

 

good point.....I can't explain why fixing my U-joint got rid of the noise at the stop lights. It could be that taking the stupid thing apart and installing a new one fixed an unrelated problem.
could be the clutch plate needs some attention.

 

Hello all. I'm new to this forum, but would like to reply to this thread. Dman777, lemme point you in a different direction. Check your Harmonic Balancer/Crankshaft Pulley. I had a similar whining noise with my 1991 240 (B230) coming from my engine compartment. It was loud enough to hear it when the windows were up and I could only hear it at idle. Also like yours, it would take a minute to start whining after I put the car in drive. Sometimes sitting at a light, it would go away, but eventually it would return.

Try this. Loosen your alternator belt, start the car and see if the noise goes away. Loosening this belt takes some stress off the crank pulley. Try this with the A/C compressor belt too. In my case, loosening and tightening these belts would cause the noise to go away and return respectively. The alternator and A/C compressor both have the crank pulley in common.

When I removed my crank pulley I saw that the two "halves", if you will, were no longer fused. The metal center piece that the 24mm bolt goes through and the outer portion with the belt channels are separated by a rubber ring secured with a bonding agent of some sort. Over time this bond degrades allowing the two metal portions to spin independently of one another. This can cause a loud whining and sometimes a periodic grunting noise (as it was with my car).

If tinkering with the alternator and A/C compressor belts don’t give a clear clue toward the balancer/crank pulley, you may have to take the pulley off (use tool 5284) and see if you can spin the two pieces by hand. My pulley was degraded enough that I could but it may be that only the power of the engine will be able to spin yours, so it might look like your pulley is fine when it’s really not. If you can’t spin it by hand to diagnose it for sure as a bad pulley, and if you happen to have one lying around, install it and see if this solves your problem. I just did this about two weeks ago and it’s an easy fix. Let us know how you make out. Hope this helps. Good luck!

 

What kind of car? My 1987 740 had a low rumbling noise. Turned out to be the fan on the intercooler. Go to www.stepbystepvolvo.com, click on "Noises, Poor Performance . . ."

 

Some auto transmissions can make some pump noise if they are low/high on fluid. Some autos just have noisy pumps too.
I would check trans fluid level.
It has to be engine or trans if it happens when car is stationary.

Regards, Andrew.

 

I'm about to buy an 86 volvo with a similar problem, the seller told me it needs a new fuel pressure regulator...maybe try that. (the sound was coming from almost right under the driver's side seat)

 

I had the exact same issue with my 81 240 and I mean exactly the same issue you are describing. It was the transfer/fuel pump the one in the fuel tank. It started with just the noise then a couple of weeks later it would hesitate and stumble when taking off from a stop. I replaced the in tank pump with one from a local salvage yard and the issue went away completely. It can be accessed from the trunk on a sedan and under the carpet in the rear compartment of a wagon.

Be warned the retaining ring or lock ring holding the pump assembly in place was nice and rusted it took some penetrating oil and alot of patience to get it off and back on.

 

As I stated my 81 240 had the same issue it started with the noise then a couple fo weks later it began hesitating when taking off from a stop.

The transfer pump was going bad the one in the tank, I replaced it and the issue is resolved,

It can be accessed from the trunk on sedans and under the carpeting in the rear compartment on wagons.

One word of advise the retaining ring holding the pump assembly in place was nice and rusted it took alot of patience not to damage it and work it off slowly I replaced it with a new ring when I reinstalled the pump assembly.

 

What's weird this noise has stopped completely. Since then the modifications I have done were new rear coil springs and new oxygen sensor. I hope it doesn't come back because I replied to this thread with an update.

 

Hopefully that solved it. Since my last post about the harmonic balancer, I’ve had another whining noise to pop up. I started to wonder if this one was more like yours to begin with, Dman777. I think this one is in the transmission. It only happens when the car is moving and it’s sometimes intermittent. The faster I go, the higher the pitch, and sometimes it comes and goes every 5 to 10 seconds or so. When it’s intermittent, it sounds like a mosquito buzzing around your ear. It also seems that as the engine or transmission warms up, the noise decreases and is heard less and less.

I drained the tranny fluid and replaced it with new to no avail. I’m gonna check the level to be sure it’s right. I don’t know much about transmissions, but I think I’ve either got some bad bearings or something, or she’s on her last leg. No shifting or driving problems though. Drives and shifts perfectly and consistently.

 

IBCMoore...

Did you ever find out what this noise was?

My car does the exact thing...my son thinks it's great...sounds like we're taxiing for take off!