Mud-club

Vehicle & Technical => Discovery => Topic started by: stevepage3 on September 03, 2008, 09:52:37

Title: Engine compression test
Post by: stevepage3 on September 03, 2008, 09:52:37

Hi

I have a 3.5v8 and am trying to do an engine compression test.

I am getting about 160 psi in each cylinder the haynes manual says 150 minimum for low compresssion engine and 170 psi min for high compression engine.

Not sure what mine comes under is 160 psi ok ?

Thanks

Steve

Title: Re: Engine compression test
Post by: andyb on September 03, 2008, 10:14:23

160 sounds fine. I guess it's a high compression engine that is a little worn.....but still only 5% shy of the 'new' figure.

Your compression readings should also be with 10% of each other as well or else this is an indication of a problem.

HTH

Title: Re: Engine compression test
Post by: stevepage3 on September 03, 2008, 10:28:15

Hi

Thanks for the prompt response, The car has just turned 100,000 miles so 5% doesn.t sound to bad.

Thanks

Title: Re: Engine compression test
Post by: Range Rover Blues on September 05, 2008, 19:05:39

If they are all reasonably even then I'd be happy with that.

Did you remove all 8 plugs first or each one as you tested that cylinder?

Did you have the throttle wide open?

Cranking speed and throttle onening can make a difference to the pressure you register.

Now, my LSE reads 205 psi on all 8, but it is 'tweaked' a bit.