First off, I am new to this forum and a new "old" Volvo owner. I really appreciate all the threads out here - highly valuable information. Bought a 1997 Volvo 850, non-turbo from my nephew - he cut me a deal ($500) - problems he was having - battery drain, clicking sound from front end, roaring sound from right tire, check engine light on and ABS/Trac lights on.

Clicking sound I think I have correctly diagnosed - CV boot was all chewed up (no telling how long like that). I am replacing both axles and while I have them apart - am changing both control arms/ball joints (it was only $5 more for the assembly than just the ball joint - so why not). The roaring sound i am guessing is the hub bearing based on the torn boot.

Check engine light code, according to what a Volvo dealer told my nephew is the air pump - will tackle that last - will be necessary to correct in order to get safety sticker.

ABS/Trac light - from reading these threads the Volvo dealer can get me code as to why these are on? Seems the abs module is a common culprit? However, when I was driving it home, I was hearing a hissing sound when I pushed the pedal - like a vacuum leak - are there vacuum lines to the abs system?

The battery drain, I believe is a badly rebuilt alternator. Nephew had it changed not long ago, but it is making noise it shouldnt be making. I fully charged it, but have not driven it and it is holding the charge. I dont think the alternator is fully charging rather than an open circuit draining it.

As to my point for posting - I am hearing a thumping sound while in park, idling. I had a jack under the car (b/c of other work I was doing and when i jacked it up a couple of times the thumping got better - would this be indicative of a motor mount?

Thanks again for this forum, so far I am enjoying working on the car. Easier to work on than my Expedition!

 

I would say motor mounts.

 

Thanks for the response tech - in reading these threads and other articles on the Net, seems to be a common problem with Volvos. Never changed a motor mount on any other vehicle I owned, is this a design problem? Is there a different motor mount I should go with or is oem sufficient?

 

OEM is good.
I have changed motor mounts on almost every car I have ever owned. Most are make of rubber which eventually dries out and pulls apart. The 850's have rubber/hydraulic mounts as well which leak the fluid out.

 

I was reading some articles and it says that the motor mount failure is actually a safety design. They design them to compress and break away so during a front end collision the engine falls down and under the car rather than going into the passenger compartment. Makes sense, lets hope I never have to test that design!!