We have an '05 XC90 V8 that we recently purchased with about 78k miles\. We've owned it for about 3500 miles and about 1500 miles ago started noticing a clunk (not sure if it just started or we somehow didn't originally notice it) on initial acelleration. Took it to a shop we trust for a general pre-purchase inspection (post-purchase... and after we noticed the clunk, maybe a thousand miles ago). We even mentioned the clunk but they didn't find any drivetrain related issues.

The clunk seems to happen on initial application of torque, like initially pulling out onto the road or hitting the gas after slowing down for a turn. It doesn't seem like a transmission "hard shift" sort of scenario because it will happen if already in first when taking off (either in auto or manual shift mode).

I'm kind of at a loss for what might be causing it. It almost feels like a loose/worn U-joint, but it's pretty noticeable. I'm wondering if it could be an engine or transmission mount, but I don't know how to diagnose it.

We're about to leave on a 3000+ mile trip so I'm concerned that I don't know what it is and how likely it is to leave us stranded! Any ideas or advice would be greatly appreciated!

 

sounds like you have a broken motor mount....I experienced the same type issue and found a broken motor mount...I hope this helps!

 

I have a 2006 XC90 that is of early giving me a similar clunking sound during acceleration. I suspect bad fuel generating a miss-fire. I've added a fuel additive without no positive result. Does anyone have any other suggestions!

 

divide you can check the mounts by doing the following...however you have to be very careful, have a friend fully depress the brake with their left foot and put the car in drive with the hood up...have them slightly depress the gas while your looking at the engine and if you have a broken mount you will see the engine lift, easiest and quickest way to rule in/out a broken mount....again please use caution should you decide to give this a try! The only other way is to take it to a mechanic and let them do it...I hope this helps

 

my clunk was caused cross bar on my front mount on the top i tightened that up and no more clunk

 

Well, we finally solved the problem after all this time. The front suspension bushings were split. After replacing all four bushings the clunk is gone!

We still have a strange creaking noise primarily on braking (seems to occur most often when the front suspension compresses) that neither us or our mechanic can figure out. I will update my thread if we figure that out. The best guesses are replacing the steering rack, which has some play in it, and possibly replacing the struts. The mechanic doesn't think the struts are causing the noise, but they feel like they should be replaced anyway as we have some front end bounce when coming to a stop.

Thanks again for the help!
-Peter

 

Also, forgot to reply to the motor mount suggestion earlier (sorry!). I did the test that patsfn2 suggested. No lifting of the motor, although the motor moves back and forth about an inch within the leeway provided by the V8 motor mount. I'm not sure why it is designed this way, but it does look correct by design not due to wear.

I still feel a small amount of dull "thunk" when the torque changes significantly, so I am wondering if a motor mount has more play than it should. It's hard to tell what's normal and what's not, though, as I've never driven a new XC90

Car feels much better without the loud clunking, though!

Does anyone have advice on the benefits/pitfalls of having the transmission fluid flushed on these? It doesn't seem to be recommended by Volvo, but I was wondering if this might take the edge of the shifting a bit. Anyone seen any real world positive results from the $250 flush???

 

I have notice the same CLUNKING noise on my 2004 XC 90 5T WITH 87,000 k AND THE SOULUTION FOR ME WAS LUBRICATION.