Compression on 5 and 6 way high

[burge31]

Did a compression test on all the cylinders, 1-4 were up to specs but 5 and 6 were reading 180....any suggestions on what this could be?

 

[SupraMan1987]

What was the next closest reading? Could be leaky injectors or something similar leading to a carbon build up.

 

[IJ.]

Sure the other 4 aren't just way low?

 

[burge31]

the other cylinders were 130 which is up to specs, im just trying to figure out what could cause the 50 psi difference

 

[IJ.]

Ummm where did you get 130 as a spec?

most GTE's are around the 150 mark 128 is the minimum and is indicating a very tired engine, more importantly is the 14psi variation allowance between cylinders.

Is this a GTE or an NA/t?

 

[paradox616]

yeah, 150psi is around 8.5:1

id say carbon build up on the pistons, maybe not igniting the fuel properly?

 

[hvyman]

130 is low and shitty power. either you got bad rings, leaky valves, or a bhg.

 

[burge31]

its a gte

 

[Jeff Lange]

Really the most important part is the difference between cylinders.

I'd say it sounds like you have 4 low, not 2 high.

Jeff

 

[paradox616]

its a gte

gte should sit round 150 accross all 6, ge should sit around 160-165? (not exactly sure but its higher than the gte)

Really the most important part is the difference between cylinders.

I'd say it sounds like you have 4 low, not 2 high.

Jeff

+1

 

[burge31]

the car has been sitting for a little while so today i went to the store and got some top end cleaner, after i run that through and redo a compression test what conclusions can be drawn if the 5 and 6 cylinders compression comes down?