hmmmmmmmmm HELP!!!!!!

[paul and sam]

can anyone help me with some advice. i have compression tested my V8 today and have come up with the following results 1=140  2=132  3-145  4=136  5=135  6=105 7=138  8=118  this is on a low compression engine and its a k reg is this in need of  rebuilding or is it about right for the age of the engine  any help would be very helpfull many thanks

[wheeler]

i think they should be about 135
whats wrong with the engine is it playing up
or did you just fancy doing a compresion test lol

[paul and sam]

just decided to do a compression test (the book says 150 mim but i assume that this is a new engine)

[bigant]

squirt abit of oil down onto the piston and do the test again if the readings go up its new rings time ^^

[Sharpshooter]

Was the engine cold or warm??

[paul and sam]

the engine was warm at the time of the test

[Tommo]

its fine. if it starts ok in a morning they your ok. only a worry if one is significantly down really.

[skip]

Being that these V8s suffer from worn cams etc, I wouldn't be surprised if the valves were not opening sufficiently to allow enough air in to get a good reading,  Try the oil down the hole trick as it will give you more of an idea.

Number 6 does look to be down about  22%, if oil doesn't make any difference it gonna be valve train related.

[Rich_P]

You also did do the test with the throttle fully open, right?

[bigant]

sorry if i was abit vague :)
do the test with the engine warm and the loud pedal all the way down to get as much fuel and air into the engine, once you have been round all 8 do it again but squirt abit of oil down the bores first if the readings go up its a good bet you need new rings if not its probs a valve problem :)
hope it helps Ant.

[paul and sam]

ok i will do this over the weekend and post the results