Low PSI (55) In 6th Cylinder

[NDLC]

Hey guys having problems with this 95' chevy lumina I have recently have obtain i got it for free because it had been over heated 3 times(Long story guys an moron) Well we broke it down replaced the head and the cylinder is good but the pressure in the 6th cylinder is still only 55 psi only at idle

V6 3100

Engine has been rebuilt pretty much new... Anything but fixing the problem is not an option

Can anyone help..?

[maxwedge]

Welcome to AF. 55 at idle, how was this determined?

[4x4 blazerguy]

Originally Posted by maxwedge

Welcome to AF. 55 at idle, how was this determined?

I was kind of wondering the same thing. Has checking compression changed in modern era?
Craig

[maxwedge]

No it has not.

[NDLC]

Whats AF? um im not really mechanically inclined its my dad and his buddy trying to fix it his buddy is a mechanic they have tried everything they could think of ... the engine was recently rebuilt (Paid for by the former owner).. They used some sort of gauge to detrimen the PSI if thats what you mean.. but as soon as they give it the gas it seals off and the pressure goes back to normal

There next guess is that it was when they rebuilt the engine one of the lobes on the camshaft was off ...

I hope i make sense if you need a more mechanical explanation ill get by dad to write one but his not very good with computers i figured i would ask around on some forums see if anyone had any ideas cause quite frankly they are out of them...

[LMP]

Originally Posted by NDLC

Hey ... the 6th cylinder is still only 55 psi only at idle..

mmm...generally, you test that just on the starter with wide open throttle.
At idle, you have partial vacuum at intake manifold so it will not boost the pressure to the "atmospheric" compression ratio.