2000 Volvo V70R Motor has Zero compression

Jason1102 · Post by **Jason1102** » 07 Oct 2013, 19:36

Good evening,

I recently blew a head gasket in my car. (I felt a loss of power pulling away from a stop light, shut the motor off, and towed the car home.) Anyway, the mechanic pulled and machined the head. I had every gasket replaced during the rebuild i possibly could. The guy mentioned early he had the cams spin during reassembly, but fixed the timing. However, for the last few weeks he has told me he couldn't get the timing correct, then he has said I needed all new coil packs and plugs because I had no spark. Now after three weeks of saying the timing was messed up, he has now said that I have zero compression on all five cylinders and the issue is now in the lower end of the motor...does this seem legit considering when the head was off he commented on how clean the cylinder walls were and how there was no composite build-up anywhere?

difflock54 · Post by **difflock54** » 07 Oct 2013, 20:02

Has your mechanic had any previous experience on INTERFERENCE Volvo motors?
If all looked 'Rosy' when the head was reconditioned and he has admitted not aligning the cams properly for the timing at rebuild, then I suspect the valves have been bent when the engine was subsequently turned over in the attempt to start her.
That might explain the Zero compressions and it could also have caused damage to pistons also.
The camshaft pulleys timing marks and the crankshaft pulley marks must be aligned correctly and must not be rotated until the timing belt is fitted and tensioned correctly otherwise the valves will interfere with the pistons resulting in damage.
Sometimes a belt may slip a tooth but that will normally only affect the timing slightly.

Try repeating compression test with a teaspoon of oil in each cylinder as the dry bores may be giving falsely low readings. The oil helps to reseal the rings and reinstate the true compressions.
If strange knocking sounds are heard, cease turning her over immediately as that confirms the valves and pistons making direct contact.

Volvoman176 · Post by **Volvoman176** » 08 Oct 2013, 00:39

I agree with diff lock, if he couldn't set the timing properly and was rotating either the crank or the cams to try and re-align (when re assembled) he could've bent valves. It really doesn't take much to bend a valve so it doesn't seat properly

Volvoman176 · Post by **Volvoman176** » 08 Oct 2013, 01:08

Jason1102 · Post by **Jason1102** » 08 Oct 2013, 06:00

So does bending the valves mean I'm looking at another tear-down?

Post by **rmmagow** » 08 Oct 2013, 08:55

At the very least. You need a much better mechanic. You shouldn't have to pay for this as it sounds like he totally trashed your engine.

Jason1102 · Post by **Jason1102** » 08 Oct 2013, 10:08

You were all right. I went back and asked him if he was absolutely sure he had the timing correct and if he wanted to go back and double check only to get a response of...and I quote..."I don't know what to do."

bugeye · Post by **bugeye** » 08 Oct 2013, 11:22

I hope you did not pay him anything! Find a known quality independent Volvo mechanic or take to a Volvo dealer. Be prepared for big $ if no compression. Let the new mechanic know of what was done and let them come to their own conclusions. If the first mechanic is a responsible person (?) his insurance should cover any documented screwups. The first mechanics insurance may want to directly interface with the dealer/new mechanic. Let us know how it works out.

Volvoman176 · Post by **Volvoman176** » 09 Oct 2013, 04:15

If valves bent at the very least it will be head off again, the full extent of damage can't be found till that's done, however no compression on any cylinders would indicate a big screw up. Valves replaced, seals replaced, potential piston damage. Again, that's speculation, but make sure you get him to pay for this because it will not be cheap.

Best of luck

vulvu · Post by **vulvu** » 09 Oct 2013, 15:37

I'm sorry to hear about yout bad luck.

One option to look for damage due to wrong timing would be to use an endoscope (or a 'snake camera') to look inside the cylinders. If the valves have made contact with the pistons, I suppose you would see some marks on piston heads.

Jani