While I am at idle (not moving), I have noticed a rattle similar to the noise a bearing makes when starting to go bad only while transmission is engaged in gear (reverse or forward gears). When shifter is placed in park or neutral the noise stops. The noise is certainly noticable, but only when radio and air are turned off, it is not as noticable as if a pulley were to be going out.

Any known causes? Where should I look? Possible fix?

Thanks

116000 mi.

 

Most likely bad engine mounts.

 

2 questions:

1) is it typical for it only to be a noticable rattle why engaged in gear? why?

2) what is the best way to inspect for a bad engine mount, where?

Thanks

 

You need to isolate where the noise is coming from. For instance, I had a car with a nasty loud rattle in idle. What I found was a rock stuck between exhaust pipes and a heat guard. The rock somehow got into a very small space and made the nastiest rattle but was really harmless.

 

1.More noticable when in gear because the motor is torqued.
2.If you look at the mounts you can see if they are bad.
There is 4 mounts. One on the passenger side between the engine and body. One drivers side under the air filter box.
2 under the car between the engine and cross bar. The lower ones are easiest to see if bad. They will crack then break.

 

You know it's funny I've noticed a similar sound in my car. It sounds like an old coffee percolator or a Mercedes diesel engine. Only happens when the car is in reverse or drive. The sound goes away as soon as you put it into park or neutral. Every time my wife drives the car into the garage I noticed it but on the open road it's not as noticeable. I don't notice a lot of engine shaking when in park and the hood is opened.

 

Allright, just bought a 2008 Xc90 with a similar sound--only in drive/reverse. How did your situations get resolved? At first I was very worried this might be the terrible issue with the Rear Engine Accessory Drive. However, a noise from that problem would be noticeable any time the engine was turned on, right?

 

best to repost a new thread in the XC90 vehicle forum (commenting on an 8 year old thread for a different model is somewhat confusing). Still the comment on the motor mounts/torque rods is valid an worth a look see.

 

I have an 2006 S40 (145k miles) and I am also hearing that rattle/grinding noise while stopped in gear... as soon as I hit the gas it goes away. I originally thought it was my broken radiator fan vibrating but the fan came on the other day. Was this issue ever resolved? My car is still under the ext. warranty.
Thanks!

 

auto or manual transmission?

 

Automatic w/ the speed shift option

 

All, I figured out the rattle (with the help of a friend). The plastic hose connection between the radiator and the air filter is rattling while in gear, after putting the car in drive it looks like the engine shifts a tad causing the separation. Thought you might like to know. Marshall