Compression Test

Post by **Dubstar** » 02 Apr 2008, 19:21

I did a compression test on mine this morning and dry, both left hand cylinders are reading 140 PSI, and wet 152 PSI. The right hand bank however reads dry 121 PSI for the front cylinder and 110 PSI for the rear. Wet reads 160 PSI and 110 PSI respectively. The Autodata manual I have says it could be the cylinder head, either the seats gone or burnt out etc. Does this sound about right form anybody elses experience?
2ltr CU engine, all the left hand right hand and front is as looking at it in the engine bay from the reaer of the vehicle.
PS Can you change the head on the van?

Post by **andysimpson** » 02 Apr 2008, 19:39

From your results that sounds like a piston ring problem and not a head problem.

Post by **T'Onion** » 02 Apr 2008, 19:43

Wot Andy said ,
and yes you can remove the head whilst the engine is still in , but it will be easier to remove it , thats if you have the room etc to do it ,

I'd pull the head off and the weak barrel , replace the rings, then re-assemble and then retest , should only take a couple of hours

Post by **Dubstar** » 02 Apr 2008, 19:47

According to the Autodata book, if you do the compression test wet the second time, the results are - compression goes up then it's the rings, compression stays the same, it' the head. Or a hole in the piston. Wet by the way, means putting a capful of engine oil into the cylinder to do the test again, once you've got the dry results to compare them too.

Post by **andysimpson** » 02 Apr 2008, 19:49

Dubstar wrote:According to the Autodata book, if you do the compression test wet the second time, the results are - compression goes up then it's the rings, compression stays the same, it' the head. Or a hole in the piston. Wet by the way, means putting a capful of engine oil into the cylinder to do the test again, once you've got the dry results to compare them too.

Yes sorry did not read properly, you have one with a head problem and one with a ring problem.

Post by **T'Onion** » 02 Apr 2008, 19:54

Pull the head , its not a big job , could be that the rings are furbarred and in turn carbonned up the valves causing them to leak down , you can guess as much as like , but taking it off will be the only way you will truly find the answer

Post by **Dubstar** » 02 Apr 2008, 22:36

So can you take the head off in situ then, or is it a right pain?

Post by **T'Onion** » 03 Apr 2008, 06:40

Dubstar wrote:So can you take the head off in situ then, or is it a right pain?

yes you can , and yes it can be , depends if the tin-ware has been off in the last year or so