General: Vibration in Drive with brakes on

[bluecube50]

Hi All,
I recently purchased a pristine V70 D5 sports auto on an 04 plate. to join my 96 850 petrol auto estate. Full history and loads spent on it 127,000 miles
I have found that when the car is in drive and I am holding it on the brake (at a junction for example) there is VERY noticeable vibration through the drivers seat and it feels like a massage chair on slow setting.
If I slip her into neutral or P the vibration is not so noticeable but still there.
I had her serviced recently and asked them to check mountings, they said all ok and that five cylinder diesels do vibrate !! Im not convinced, it just doesnt feel right.
Problem is my petrol auto is as smooth as silk on tickover so maybe im just over cautious.

[R-P]

You say the mounts have been checked, but reading the title, that was my first suspect.

I recently blocked off the leaking front pad and the indeed always present vibration got much worse.

They are very easy to check: just disconnect the horizontal output of the small valve in front of the airbox and suck hard. Then seal it off with your tongue. If it comes loose within 5 seconds, there is a problem with the engine mounts.

You may need the vertical-bottom-side output, but I think I remember the thing to be very counter intuitive:
- the vacuum comes from above/the_left_side and is inputted on the bottom connector
- the output goes to the bottom of the engine but is attached on the valve on the side-output.

Volvo logic...

[bluecube50]

Originally Posted by R-P

You say the mounts have been checked, but reading the title, that was my first suspect.

I recently blocked off the leaking front pad and the indeed always present vibration got much worse.


They are very easy to check: just disconnect the horizontal output of the small valve in front of the airbox and suck hard. Then seal it off with your tongue. If it comes loose within 5 seconds, there is a problem with the engine mounts.

You may need the vertical-bottom-side output, but I think I remember the thing to be very counter intuitive:
- the vacuum comes from above/the_left_side and is inputted on the bottom connector
- the output goes to the bottom of the engine but is attached on the valve on the side-output.

Volvo logic...

Dumb, I know, but do I do this suction test with the engine running ??

[R-P]

No. You create the vacuum by sucking. Normally this is created by the vacuum pump on the top/left side of the engine. But now you are testing if there is a leak in the engine pads. So you disconnect the tube leading to them after the valve that controls them (on the airfilter-box) and apply a (partial) vacuum to it by sucking. I used 5 seconds as a rule of thumb, but if sealed properly, it should (in theory) keep your tongue sticking to the tube-opening for minutes or even hours.

There may be some grease/dirt on the tube, so check your face before going out in public again afterwards

[weedeno belfast]

Check top engine mount is away or been replaced with a pollybush if been poly bushed its were the noise is prob coming from try replacing it with one from frf gd luck