Question about P2 Engine/Transaxle Mount Failure

Post by **KidsV70** » 21 Aug 2019, 19:20

Folks,

Okay, so here's the deal- when I am driving, and let off on the gas, or (sometimes) accelerate, the V70 makes a popping or "clunk" sound. The sound comes from the front right side of the car (as seen from inside the car). We can replicate the sound while sitting by shifting back and forth into drive and reverse and revving the engine with the brakes applied. In the last thousand miles or so, I've replaced the upper engine mount, the lower torque mount (transmission to subframe), and the "front" engine mount (which attaches the engine to the subframe under the crankshaft pulley). In fact, replacing the last one seemed to fix the problem for a little while. I've checked the other two engine mounts (the cylindrical hydraulic mounts) and while both are clearly old, they don't look too bad. There's no leakage I can see, no torn rubber, etc. They are collapsed somewhat as I can move the wire straps a bit. Maybe a half inch? Oh, and the car has 216,000 miles and there's no indication that these mounts have been replaced. I have repair records,but no idea if the records I have are a complete list or not. Lastly, I had it up on ramps, and I can see that lower mount flex, but it is not collapsed or moving a lot. The original lower mount did the same thing, though it was more loose- I could flex it by hand. Years of leaking oil had softened the rubber, but it too wasn't collapsed in the typical way you see them fail.

So, the questions are these-
- How do I tell if those cylindrical mounts are bad, short of the obvious indications of collapse?

-What else might be wrong with it?

- How problematic is it to drive the car? The sound is unpleasant but it doesn't appear to do any damage.

Thanks in advance, everyone!
Bert

MDK · Post by **MDK** » 21 Aug 2019, 20:23

So, MDK here. Those other 2 I call acorn's. That's what they look like.. big acorn's. 2 me it sounds like sway bar bushings or maybe lower control arm bushings. Have you ever replaced the upper spring seats? Those make a poping noise. Usually the acorn's leak fluid..

Post by **June** » 21 Aug 2019, 20:31

My 2004 P2 it was the subframe bushings. Absolutely drove me crazy enough to replace every suspension part to no avail. Then the rear main seal sprung a leak and I insisted the subframe bushings were to be replaced since the frame was on the ground. To my surprise it cured the problem. So if everything else checks out consider the bushings. June

Post by **vtl** » 21 Aug 2019, 20:36

Almost stripped collar sleeve can do that. Propeller shaft's front CV joint, too.

Post by **KidsV70** » 22 Aug 2019, 17:28

MDK wrote: ↑21 Aug 2019, 20:23 So, MDK here. Those other 2 I call acorn's. That's what they look like.. big acorn's. 2 me it sounds like sway bar bushings or maybe lower control arm bushings. Have you ever replaced the upper spring seats? Those make a poping noise. Usually the acorn's leak fluid..

The upper spring seats look ok from the top , FWIW. Wouldn't the car have to be moving for those to make noise?

Thanks!

Post by **KidsV70** » 22 Aug 2019, 17:30

June wrote: ↑21 Aug 2019, 20:31 My 2004 P2 it was the subframe bushings. Absolutely drove me crazy enough to replace every suspension part to no avail. Then the rear main seal sprung a leak and I insisted the subframe bushings were to be replaced since the frame was on the ground. To my surprise it cured the problem. So if everything else checks out consider the bushings. June

Interesting, June. Can you explain more about what you mean by subframe bushings, though?

Post by **KidsV70** » 22 Aug 2019, 17:34

vtl wrote: ↑21 Aug 2019, 20:36 Almost stripped collar sleeve can do that. Propeller shaft's front CV joint, too.

Oops! It's front wheel drive, so no collar sleeve. I should definitely check the front CV though. Thanks!

Post by **June** » 22 Aug 2019, 18:18

KidsV70 wrote: ↑22 Aug 2019, 17:30
June wrote: ↑21 Aug 2019, 20:31 My 2004 P2 it was the subframe bushings. Absolutely drove me crazy enough to replace every suspension part to no avail. Then the rear main seal sprung a leak and I insisted the subframe bushings were to be replaced since the frame was on the ground. To my surprise it cured the problem. So if everything else checks out consider the bushings. June
Interesting, June. Can you explain more about what you mean by subframe bushings, though?

Here are photos of the subframe and a genuine Volvo new subframe bushing. The subframe is where the lower engine mounts attach the engine/ transmission and suspension to the body of the car. The rubber bushings wear out and make a popping sound with the engine torque. Also when they get really bad the car will pull one way than the other going down the road. June

Post by **KidsV70** » 22 Aug 2019, 18:32

Okay, thanks! I didn't realize there were bushings in there. I imagine they are there for more NVH reductions. *sigh*

Post by **June** » 22 Aug 2019, 18:37

Also the bolts are torque to yield one time use only. So new bolts must be installed. June