no compression

tshaw62 · Post by **tshaw62** » 28 Feb 2013, 00:58

had a machine shop do a valve job after the car got hot. Anyways put it back together and i dont have compression.All the timing marks are lined up. the vvt seems right. The cam cant be 180 out the gear wont line up with the marks . I dont know any suggestion on what I should do? its a 2.8 turbo s80 t6 thanks in advance

Post by **JDS60R** » 28 Feb 2013, 10:22

Time for a leak down test. By offering compressed air into the spark plug hole ( by use of a leak down tester or compression tester with schrader valve remove) you can find out where it is leaking.

The VVT if taken off the cam can be put on incorrectly so you may have a valve timing issue.

If the engine was spun by starter instead of by hand (right after timing belt was put on) and valve timing was off you may have bent the valves.

Do a leak down test ( hundreds of videos on Youtube etc) and let us know what you found

tshaw62 · Post by **tshaw62** » 28 Feb 2013, 14:25

Im trying to do a leak down test and the piston is supposed to be at top dead zero. If this is correct the mark above the crank isnt top dead zero. So now I dont know what to do. Wouldnt the cams be off being I moved the crank if I leave them lined up with the marks on the cover?

Post by **JDS60R** » 28 Feb 2013, 15:28

The crank mark is not top dead center . Volvo calls it "timing position" among other things. Its about 1.5 teeth away from TDC.

You can put a long screwdriver down where the piston is and watch it rise and fall. Anywhere at the top of the compression stroke should work fine.

Post by **boosted5cyl** » 01 Mar 2013, 11:20

So it got hot and blew the head gasket?
As advised, use something to drop into the plughole to find TDC for each cylinder. Apply something smally like PSI to start with and see where it leaks out. Some leakage into the crankcase is normal, if its gushing though you might have a problem.

tshaw62 · Post by **tshaw62** » 07 Apr 2013, 19:23

turns out my friend turned the motor and all the exhaust valves got bent. Ive replaced them and reassembled the motor making sure the cams are lined up with the seam.should one lobe be down on intake and the other lobe up on the exhaust/

manuel53 · Post by **manuel53** » 13 May 2013, 10:10

Hello I had almost same problem, I am the one who have to put togheter this engine , have done replace bent valves, the problem is that the guy who removed the head , remove the cams gear out of the cams , can you tell me how put it in the rigth position ?
it will be very very apreciatted. if you have a diagram it´ll be great thank you.

Eldoninoz · Post by **Eldoninoz** » 13 May 2013, 10:23

Here is a tutorial on replacing the head on a 850, very similar to your motor on procedure.

http://www.tracystruesoaps.com/tutorials/850hg/p8.html

For the VVT here is some information on setting that.

https://www.matthewsvolvosite.com/forums ... hp?t=34642

Hope this helps