15 replies to this topic

[BlackBrick]

I've been trying to diagnose a groaning noise...(and thanks to all who have offered suggestions the last month or so). The noise sounds like it's coming from the transmission/lower back of engine area.

It only groans while in Drive, Reverse, or Low. It groans while driving AND while idling, especially under load. The groan noise goes higher/lower in pitch depending on the RPM. It goes away when put into Park or Neutral. So I am mostly assuming bad transmission. But, it shifts like new. No leaks at all. Noise doesn't seem linked to steering pump.

I've checked the engine joints, and they seem fine.

I've checked the axles, and they seem fine.

I just flushed the transmission, and it didn't make a difference.

Recently, I've located the noise to be just below the turbo area...so now I'm thinking, this could easily be a bad turbo bearing!?

But do our turbos cut out when put into neutral and park?

1997 Volvo GLT w/ 116,000 miles.


Thanks for any help! Otherwise, I'm almost ready to take her in and have a professional diagnose the sound (which can get costly!)

[Rsterns]

BlackBrick, on 22 May 2010 - 05:54 PM, said:

I've been trying to diagnose a groaning noise...(and thanks to all who have offered suggestions the last month or so). The noise sounds like it's coming from the transmission/lower back of engine area.

It only groans while in Drive, Reverse, or Low. It groans while driving AND while idling, especially under load. The groan noise goes higher/lower in pitch depending on the RPM. It goes away when put into Park or Neutral. So I am mostly assuming bad transmission. But, it shifts like new. No leaks at all. Noise doesn't seem linked to steering pump.

I've checked the engine joints, and they seem fine.

I've checked the axles, and they seem fine.

I just flushed the transmission, and it didn't make a difference.

Recently, I've located the noise to be just below the turbo area...so now I'm thinking, this could easily be a bad turbo bearing!?

But do our turbos cut out when put into neutral and park?

1997 Volvo GLT w/ 116,000 miles.


Thanks for any help! Otherwise, I'm almost ready to take her in and have a professional diagnose the sound (which can get costly!)

By stating that it goes away in neutral or park, I have to assume that it only makes the noise while the car is moving? If this is the case, have you ruled out your front hubs? When that bearing starts going bad it can make a variety of sounds.

[rocketman4321]

Any vibration, or just groaning noise? I'm thinking engine mounts or the serp belt idler, but neither is really in the area you cite. (Rear hydraulic mounts don't usually go, per other posts here.) I did chase a groan under acceleration for a long time, and it turned out to be the idler--which seemed fine when spun by hand.

[troyhyde]

When you put the car into gear the engine will shift a little in its placement in the engine bay. Any chance you are getting something physically rubbing? Can you get someone to put the car into gear, keep their foot on the brake, then give the car a little gas. Something out to pop out pretty quickly. Maybe the exhaust is hitting something.

Doesn't sound like a turbo issue to me unless you want to include heat shield to the equation.

[BlackBrick]

I've ruled out the hub and axle or anything suspension related, because it also makes the noise when the car is stationary.

There is no vibration, and it's definitely not a rattle. It sounds like an engine or transmission groan to me, and less bearing sounding.

Because it only happens in gear, even while stationary, I have to assume it's the transmission. And although it's RPM related, I cannot get the noise to happen when in neutral or park. But it shifts sweet, which makes no sense if it's the transmission.

Could the transmission fluid pump be going out?

About the only thing I can relate the groaning sound to is the sound of a hydraulic press.

[Rsterns]

BlackBrick, on 23 May 2010 - 02:39 AM, said:

I've ruled out the hub and axle or anything suspension related, because it also makes the noise when the car is stationary.

There is no vibration, and it's definitely not a rattle. It sounds like an engine or transmission groan to me, and less bearing sounding.

Because it only happens in gear, even while stationary, I have to assume it's the transmission. And although it's RPM related, I cannot get the noise to happen when in neutral or park. But it shifts sweet, which makes no sense if it's the transmission.

Could the transmission fluid pump be going out?

About the only thing I can relate the groaning sound to is the sound of a hydraulic press.

Based on everything you've said and already ruled out, the transmission pump is a logical candidate for being the culprit, and not making the sound in park or neutral falls in line with the scenario.

[BlackBrick]

Rsterns, on 23 May 2010 - 04:11 AM, said:

Based on everything you've said and already ruled out, the transmission pump is a logical candidate for being the culprit, and not making the sound in park or neutral falls in line with the scenario.

Yeah, unfortunately that's becoming my conclusion also. So, what to do? Is this an easy fix without having to yank out the transmission? Do I just run it until the transmission goes? Can the pump run for years at this point?

[Rsterns]

BlackBrick, on 23 May 2010 - 05:24 PM, said:

Yeah, unfortunately that's becoming my conclusion also. So, what to do? Is this an easy fix without having to yank out the transmission? Do I just run it until the transmission goes? Can the pump run for years at this point?

The only answer I can provide to your question is 'Time will Tell'. If you can tolerate the grown, then run it till it fails. Just make sure you have a good road towing service account, because when it fails your not going anywhere. If I'm not mistaken, the transmission will need to be removed to have the pump replaced, at that point I'd get a rebuilt transmission which either way equals a significant reinvestment in your car.

[BlackBrick]

Thanks for the help. You're right...it's one of those wait and see. I first heard a little bit of the groan about a year ago, but dismissed it because it was only under load while driving, and was faint. These 850's are so tough, you can usually push something that's failing for quite a while.

The mileage is low (116,000), and I've maintained this wagon for 7 years now. I won't give up this early, so a transmission swap may be in my future one day. For all I know, it may not even be the transmission.

I have AAA, so thanks for the advice.

Any others with similar sounds, I welcome your experiences.

[BlackBrick]

Latest...now there is a vibration/sound sometimes after driving and coming to a stop (while still in drive). It is not through the steering wheel though, and it sounds like its coming from behind the passenger floorboard. Also, the sound is very pronounced during turning right at slow speeds while accelerating.

My conclusion is that now the right axle is going? (I had the left axle replaced 2 months ago).

Hopefully time has told, and it's just both axles causing all the fuss.

There is 115,000 miles/13 years of wear, which I assume is a good life for an axle? (CV boots never been changed either)

[BlackBrick]

BlackBrick, on 18 June 2010 - 07:34 PM, said:

Latest...now there is a vibration/sound sometimes after driving and coming to a stop (while still in drive). It is not through the steering wheel though, and it sounds like its coming from behind the passenger floorboard. Also, the sound is very pronounced during turning right at slow speeds while accelerating.

My conclusion is that now the right axle is going? (I had the left axle replaced 2 months ago).

Hopefully time has told, and it's just both axles causing all the fuss.

There is 115,000 miles/13 years of wear, which I assume is a good life for an axle? (CV boots never been changed either)

Anyone out there!? Looks like I'm chasing two ghosts. The new axle has eliminated the loud noise and vibration. The light groan is still there, BUT upon closer examination, the OEM upper engine mount (behind dashboard) is torn. (And it's only 2 years old!) Maybe THAT is what has been causing the mild groan? Someone here had mentioned engine movement could cause this noise. Fingers crossed.

[BlackBrick]

10,000 miles later, it died. the groan was a bad transmission.

[survolvo]

Time for a swap!

[BlackBrick]

just put in a used a/t with 118,000 miles. It is shifting rather nice, and groan is of course gone.

And the wagon is my wife's car...she hates manual shift.

[survolvo]

Ha I know how that is. My girl refuses to drive stick. So until I get my own car, I'm stuck with the autotragic. But I told her that the only time I'm gonna mess with the tranny, is if its a m56

[BlackBrick]

most of my cars have been stick, but i am so sick of commuting with one. I welcome the a/t, and especially like the 850's. 1st, 2nd, 3rd, repeat about 40 times a day wears on you!