Thump on start up. V70 d5 auto
 

Hiya, I have a strange thump or the sound of a loud knock when I start my v70, sometimes when I turn her off.
It’s after the starter runs and as the engines idles.

It’s a 2004 d5 auto.
Runs fine other than that. Gears all good, idles fines. No power loss

You can feel the thump inside the car. It’s like the engines hitting something.
I’ve had the lower mount and top front mounts replaced recently.
Any ideas?

Have you tested the vacuum mounts and checked that the gearbox is clearing the subframe by a good 10-15mm?

I’m going to have a good look tomorrow, how many mounts are there?
Thanks

Have you tried starting it in N, I find (with mine) that I've when parked up that the car is still slightly on the bounce when it goes into park that it seems to catch on something, sounds weird I know, but, if I then drop it in to Neutral, you can feel the tension release and then knock it back in to park, all is well, the same thing when parkin on a hill (up or down), if using Park before the handbrake, the tension is applied to the box, again, N before staring will release this tension and starting is easier too. Perhaps yours it a totally different issue to mine.....

Hi, yes I’ve tried park and neutral. Still the same.
I’m going to check the vacuum system and have a look at the lower right mount today. Hoping that sheds some light.

If you find you need new vacuum mounts,I have a couple brand new good quality ones for sale in the classifieds,significantly cheaper than retail price. Bought them and ended up changing the car before I got round to fit them!