My 01 V70 has had a rattling sound along with a vibration that can be felt in the accelerator pedal. It only happens at speeds between 25-35mph and 2,300-2,500 rpm's. The sound does not happen if it's in park or neutral.

I have recently changed the timing belt, tensioners, water pump, flame trap, hoses, and upper torque mount which was totally shot but the issue with the rattle and vibration is still there. I have gone thru and checked all the bolts on the heat shields and they are all tight. I have also looked at all the engine mounts and they look fine except the torque rod which can be twisted very slightly by hand but no where near as bad as when it totally failed last year.

I greatly appreciate any help with this because this has left my friends and I totally stumped.

 

Going to take some big swings here.Grab an assistant, place the car in drive w/hood up and brake torque the engine and observe engine movement. If all is well, check the drive line for issues, such as bad wheel bearing, binding cv joint, bent wheel or tire hop, steering components or ball joints. A lift or jack stands will help at this point.The rattle may be a failing converter or muffler baffle failing. Some additional questions: how many miles and does the vibration go away at what mph?

 

I replaced the cv's about 9 months ago along with the wheel bearing hubs, control arms, endlinks, upper spring seats, and upper strut mount bearings. I did look thru them and they still seem like brand new. I did torque test the mounts and the only one that I can see that had any movement is the passenger side motor mount.

Here are some pictures of it. As you see I still gotta clean up around there from all the work that was just completed due to an oil and water pump leak.




The car has 158k on it. The issue starts at speeds between 25-35 mph and the rpm's have to be between 2,300-2,500 for it to happen. Once it is above or below those rpm's and speeds the sound and vibration totally goes away. I have not noticed any acceleration issues nor any shift flares or slippage. I also checked the transmission fluid level and it is good and the fluid is still nice and red.

 

Well I replaced the mount today. It didn't seem as bad as I thought it was but after everything was back together and I took it for a test drive the noise and rattle is still there starting and stopping at the same points as before. Anyone have any ideas on what it could be and what I should look at?

 

I just got back from taking the car out and think it could be the catalytic converter. The car now has the noise and vibration at any speed as long as it is at 2,300-2,500 rpms. I was told by my friend that she can feel the vibration on the passenger side at her feet near console. I also remembered that about 6-7 months ago the check engine light came on one morning when starting the car and was told that it pointed to a bad catalytic converter. A tech friend of mine said it was probably a fluke since the car showed no signs of a cat going bad
Anyone had any experience with a bad catalytic converter?

 

Have you swapped the wheels from front to back?

 

Well I finally solved what was causing the vibration and rattle. The mesh on the down pipe had broke apart on the inside. Once the down pipe was replaced the rattle and vibration went away. I guess it got tore apart when the engine and torque mounts went bad and caused all excessive engine movement.

 

Thanks for posting this thread. This exact same problem started happening intermittently last week with my 2004 V70. I scheduled an appointment at my local Volvo dealer today to get it checked out and I was told the sound is caused by an internal part failure with my catalytic converter and that it will only get worse and the "check engine" light will eventually come on. They recommended replacing the catalytic converter but said I didn't have to do it right away after I said I hadn't planned on spending $1400 today. After reading your post, I think I'll definitely get a second opinion...

 

Please get a second opinion, My catalytic converter went out on my 01 V70 and I took it to a muffler shop after my local Volvo dealership told me what the problem was. The Muffler shop only charged me $200 for my new catalytic converter but it was an aftermarket one. But it has been on my car for a year now with no issues and the muffler shop was able to get the check engine light off. Good luck