2007 XC70 (P2) - Excessive Vibrations Under Acceleration Topic is solved

[cmayo1]

As the title says, my XC70 is experiencing lots of vibrations when accelerating, but it doesnt happen when at high speeds. I believe it is the engine mounts, but as I've replaced 3 out of 5 (top of engine, bottom near oil pan, passenger side behind wheel well), I haven't noticed much change. When I changed the one ontop of the engine, my steering wheel would no longer shake on startup, and it generally served as a good start, but after replacing the other two I'm not getting the same results. The top one was junk, the bottom one wasn't too bad, but definitely showing age, and the passenger side one was actually in pretty good shape.

Before I order the other two engine mounts, should I be looking at CV axles? Not sure if they've ever been replaced (234k) and I definitely have a power steering leak which is probably one of the axles. My tires were balanced about 5 months ago.

[vtl]

Vibration under acceleration is usually worn tripods in axles. If you're handy, you can add a shim to tripod, so it sits deeper in the housing. Or convert to XC90 2.5T axles.

[Blacklab467]

This sounds like classic CV axle failure, most likely the passenger side. I would ask to confirm; what speed does it vibrate most at, has it been getting worse rapidly, is it worse on heavier acceleration? You mentioned that it goes away under lighter load (ie: cruising or coasting downhill).
Your options are: new GKN Loebro axles or used GKN axles from an auto salvage yard. DO NOT buy aftermarket Chinese axles.
There's countless topics on this forum describing this problem and the symptoms to diagnose. If you're on a budget you might only change the passenger side first to eliminate the most likely culprit.
The good news is they are relatively quick and easy to change.
viewtopic.php?p=632805&hilit=vibration+ ... on#p632805

[cmayo1]

Are there any other symptoms that would point towards CV axles vs engine mounts? $600 is almost how much i paid for the car lol. This symptom is not new, it's existed over the 16k I've had the car for

It doesn't matter the speed, more so the RPMs, probably around 2300 does it get bad, with more it's worse. I'm usually not going above that until I start getting onto the highway so it's hard to differentiate between speed vs acceleration but I will go slower today. Once I'm cruising on the highway at a steady 2700 RPMs it's fine, not noticeable, but when I step on the gas even a little it starts again.

I also feel like I'm not getting a ton of power out of the engine (she's long in the tooth though) which makes me believe the engine vibrating is causing it to not deliver as much power?

[cmayo1]

Oh! It stops vibrating when I turn at higher accelerations

[cn90]

On a flat surface with rear wheels chocked etc...
- Measure tire runout.
- Check axle for any play.
- Check rims for damage.
- Check tie rod play
- Check control arm ball joints

[jonesg]

I put the front end on jackstands, chocked the rear wheels, removed the haldex fuse , remove front wheels , started the engine and put it in D, let the wheels spin at idle ...a $15 stethoscope found the source , it was a front bearing.
https://www.amazon.com/ZKTOOL-Mechanics ... 9idGY&th=1

[Krons]

I know many have not had good results with off brand CV axles but I’ve had decent results with TRQ brand ones.

On engine mounts make sure to go with Volvo or OEM brands like those on FCPEuro. I took a chance on the front and rear round ones and vibration was worse than my old OEM ones.

[ignatz]

Two of my Volvo's went through an acceleration stutter with heavier acceleration, but would always run smooth out on the highway. New spark plugs fixed them both. Also both cars never threw a check engine light. Just a thought in case you might think its coming from the engine.

[cmayo1]

I will get under the car this weekend to check a few things out.