what is the minimum allowance on a compression test on a uk z tt

 

tis for bird he is doing a compression test and needs to know what the minimum is-that is ok

his results are

9

8

9

8.75

9

7.5

 

is this bad or ok

wot are the readings in psi.

not sure but 3.5 = 50 psi if that helps

 

im getting texts from bird and relaying them on here, so bear with me

the very minimum you want reading on a cylinder is 125psi.hope for 145psi on a healthy engine.on the lower cylinders add oil and do test again.if the readings come up then it indicates rings.did you find the lowest reading on one of the rear cylinders?

if the 7.5 is for cylinder 6 then thats a tad low

 

7.5bar=approx 110psi v low

8.0bar=approx 115psi v low

9.0bar=approx 130psi low

 

10bar would based on an engine in new/very good condition roughly 150-155psi

 

id double check the readings and make sure either the gauge/procedure was correct

if the procedure and everything checks out the same,then it will explain poor running/performance :(

if the procedure and everything checks out the same,then it will explain poor running/performance :(

cheers bud you got pm, are we talking rebuild here, or something a little less drastic (fingers crossed for bird) :bow:

he allso needs his throttle bodies wide open and his readings will be higher and true

if the 7.5 is for cylinder 6 then thats a tad low

 

7.5bar=approx 110psi v low

8.0bar=approx 115psi v low

9.0bar=approx 130psi low

 

10bar would based on an engine in new/very good condition roughly 150-155psi

 

id double check the readings and make sure either the gauge/procedure was correct

 

1 bar is 14.2 psi so that should be 142 for a new engine?

 

Or did you mean 11 bar mate?

1 bar = 14.5psi ;)

did he test it wet(oil) and dry to check if low compression is rings or valves ?, and with all plugs out at the same time.

OK, firstly the test was done dry (throttle bodies open on all tests done)

and the figures above are the dry ones.

 

7.5 was on cylinder number 6 or the one at the back on the passenger side!

i then done it wet and it went up to 9.

Now this basically points straight to the rings and an engine rebuild (bottom end).

 

I dont know if its worth it though :(

 

i could cry after spending so much on everything else and then finding this :cry: :cry: :cry:

1 bar is 14.2 psi so that should be 142 for a new engine?

 

Or did you mean 11 bar mate?

 

i did not use a calculator :wack: i was just saying approx 150 is a good healthy figure so for example 1bar=14.5psi 10x14.5=145 :cool:

 

7.5 isent lol

Nae problem mate, just wanted to clear up the little inconsistency for future ref, as I'm planning to do a compression test myself shortly, a bit scared to though lol even though car seems healthy and strong.

Your all wrong 1 bar = 14.5037738 pounds per square inch.

Your all wrong 1 bar = 14.5037738 pounds per square inch.

 

lmao and! so 14.5 it is then :rolleyes: :tongue:

lmao and! so 14.5 it is then :rolleyes: :tongue:

 

yeah, dont think my compression gauge goes up in 0.001 of a PSI LOL :rolleyes:

yeah, dont think my compression gauge goes up in 0.001 of a PSI LOL :rolleyes:

 

 

you know that,i dont know! these taffs,they have to be so perfect :smash: :)