2004 Cayenne s 8 cylinder 5 of 8 plugs wet with gas

[Renzo511]

Checked compression this morning with car cold (65 degrees outside)

 

I had 120 across each cylinder ... compression seems low but I'm getting feedback Because it wasn't a warm engine but the same reading across all 8 is stable.. could my misfiring and unburned fuel be a valve issue at this point.

[JFP in PA]

A bad valve should have shown up in the compression test.

[Renzo511]

Is 120 psi across all 8 cylinders  ( 1 or 2 psi variable ) on a cold engine bad ?

[JFP in PA]

No idea, we never check them cold, so I have no reference point.  Do you have access to a leak down tester?

[Renzo511]

I do not have leak down test equipment. 

Is the fact that each cylinder compression is almost identical to each other a good thing ?

[JFP in PA]

12 minutes ago, Renzo511 said:

I do not have leak down test equipment. 

Is the fact that each cylinder compression is almost identical to each other a good thing ?

 

They are equal, but lower than I would expect.

[lewisweller]

On 30/04/2017 at 6:03 AM, Renzo511 said:

Is 120 psi across all 8 cylinders  ( 1 or 2 psi variable ) on a cold engine bad ?

Don't seem right to me. I thought 180 was more like it. 

Other cayenne S owners recorded 180-200! 

 

You stated you had 170 before and number 8 was lower at 158! 

 

I'm confused now? 

Edited May 1, 2017 by lewisweller

[wizard]

You earlier stated compression at 170 on all but one cylinder. Hot engine?

 

Unlike others, I'm no expert by any means, however, if compression is more or less equal across all cylinders but the problem affects only 5 cylinders, then perhaps it's something else.

 

As both banks are affected (but not all cylinders on at least one bank), then it still suggests injectors to me. You have replaced and checked all coils and spark plugs presumably?

 

If you're still on the original injectors at 140,000 miles, then I'd suggest running a good injector cleaner through the system, after cleaning all your new plugs. Cheap and easy.

 

If that doesn't do anything to resolve the situation, then at least it will shut me up (-;