hi

I did an compression test on my escort rs turbo and it read:

128 highest and 120 lowest all four running about the same compression

is it time for an engine rebuild?

i did the test when the engine was cold

regards gray

 

do it when warm and do a wet test and see if it improves mate, should do

 

As said do it hot, and also if they are still low it'd be worth trying another tester.......

I had numerous cars i compression tested with the tester from my mates work........which apparently had been calibrated regularly yet according to the figures it produced all my previous cars had knackered engines.....(it was wrong )

 

as above,


hot engine,
Good battery, if not have another car boosting.
all plugs removed,
throttle fully open,
do comp test on each cyclinder twice for 5-10 seconds till pressure has maxed,
Then do a wet test.

Try another tester for accuracy, or pressure test your one with a accurate gauge and compressor.

 

the tester was from halfords?

 

the tester in quetion is mine brand new from halfords so no probs there. think its just a tired engine but as said we can try it at the weekend when warm and do a wet test and see what happens

 

Sorry, but that does mean the tester is correct.


i have 2 Clark unit, both brought together, one was accurate, the other under reads by 20 psi.

 

yes i know it doesnt mean they all read the same. But it reads in the 150s on my car so even if it is out his is still low

 

Fair enough,

What cam is fitted, and is it timed correctly? as this will change the compressions alot.

 

sorry mate i have just read back that last post and to read it it looks like im being a bit of a div didnt mean it like that. anyway i dont know what cam is fitted to his car think its standard also not sure if it is timed correctly. does it usually mean that something is up when comp is that low i just thought it would be a tired engine its just had new big end bearings if that makes any difference.

 

Starter compressions Change so easierly

with stuff like.

comp tester,
testing it correctly,
cam timing,
cam,
battery charge,
starter motor condition,
Engine Compression ratio,
Engine wear, bore, rings, valve seatings.

Before you go about rebuilding the engine, do a re test hot, and get a Leak test done, as this will show more up than a compression test.