1996 960 wagon 170,000. Cranked it up yesterday. hit the express way about the time it got up to temp. Running fine. A couple of minutes into the trip it developed a slight miss. Got to distination. Cranked it up to return home and the intermittent miss is now a dead cylinder. Pulled 2 year old V power plugs to find them baddly worn with white deposits. Compression test show ZERO compression on front #1 cylinder.? Pulled cover and cams, all the valves appear to be OK. Not stuck open or anything. Not the timing belt. Haven't pulled head yet, fearing the worst. Any common issues with this engine.?

 

Had a very similar experience several years ago.
Almost the same circumstance, after pulling head found it had a broken exhaust valve on the number five cylinder. My was cause by a huge chunk of carbon coming off the piston and keeping the one valve open for just a moment to get clipped by the piston, a nice little semi circle missing off the valve. The new valve was about $20.00.

Your spark plugs are white, mine were black and sooty. It turned out I was fighting a loosening intake manifold, would torque up to spec and then gradually loosen, which makes the computer enrich the fuel and cause carbon build up. So yours is puzzling, with white normal deposits, maybe a bad lifter?

Do you have access to compressed air? You could find the compression stroke, fill the cylinder with compressed air and then listen for air escaping from either the tail pipe or the intake duct.

Keep us posted.

DanR '94 964 355,000 miles (121,000 on the new engine)

 

Got it apart last night She's got a trashed exhaust valve with a torched out place in the tulip. The remaining good valve shows thermal discoloration also, so it got real hot. Very lean. I think.

Everything else looks really good, suprisingly. head seems ok piston's OK , low wear, not a lot of carbon, etc. I figured it was caused by a bad injector or something. Today, I was told by a reliable source that the intake gasket is the most likely cause. I haven't checked it yet. Its still attached to the head and it came off at about midnight last night. I guess we'll see,tonight

Hey at least its not catistrophic!

 

Wow !! The intake bolts were all very loose. One was gone. I never would have guessed it.

So, If you have a 960, get up and go tighten your inake bolts. Right now before its too late....

 

Maybe the same problem I had. You probably should have those intake bolts repaired, I would bet since the torque value is so low they might be stripped and you will not know it.

It might be worth having the whole head done, just the new valve but have the valves lapped and ground? Have no idea of the cost, new valve seals too?

DanR

 

Finally got it back together last night. 2 exhaust valves, 3 visits to the local VOLVO dealer, 6 trips to other various auto part stores, 4 new homemade tools later and its running better than ever.