Commpression test numbers hurt my feelings!

[ju015dd]

well, found this sitting under the valve cover next to the low (295psi) number 4 cylinder. Any ideas of what monster I have going on here? Numbers on driver side were 370, 295, 390, 355.








I looked best I could with a flashlight and couldn't see anywhere this piece could have come from.

[B4SouthernMiss22]

what ever it is thats not good

[ju015dd]

oh , and truck runs fine and strong as I can tell just smokes

[highraven99]

looks like one of the washer things(dont know what they are called) from the top of a valve spring

[countryraised]

Originally Posted by highraven99

looks like one of the washer things(dont know what they are called) from the top of a valve spring

check the valve spring retainers, one of them might be missing a chunk. which could allow the spring to kick over a little extra, and allow the valve to leak? giving a lower compression, unlikely but possible

[ju015dd]

hmmmmmmm, anyone have a pic of where it goes.. I have never done any engine work what so ever and not really sure where to look. Also, how do you go about fixing this to see if compression gets better?

[roccodart440]

Looks like a valve spring shim to me. VS retainers are like a half moon wedge type of thing. It definitly isn't one of them not to mention you would have dropped a valve.

A shim on the other hand would give you less seat pressure and thus lower compression.

[harley1rocker]

the valve spring retainers are fairly thick,doubt its that.my truck had broke rings,im not sayin thats a ring,but if your smokin,got low compression,then you deff got sumthin going on there..did you run contribution??? get you a cherry picker and pull the heads..i did mine.thinkin it was a valve,and thinkin i would get away with just reworkin the heads,not a chance.pulled the heads and piston was all chewed up from a peice of ring.

[ju015dd]

Originally Posted by harley1rocker

the valve spring retainers are fairly thick,doubt its that.my truck had broke rings,im not sayin thats a ring,but if your smokin,got low compression,then you deff got sumthin going on there..did you run contribution??? get you a cherry picker and pull the heads..i did mine.thinkin it was a valve,and thinkin i would get away with just reworkin the heads,not a chance.pulled the heads and piston was all chewed up from a peice of ring.

yeah I did a contribution test and just came back with 3 and 8 cylinders but they had compression about 360psi when I did the check. I was hoping to find out what this thing is and crossing my fingers I have a head issue and not a ring issue. What does a head on these things weigh, 100lbs or so? Also, how much harder is it to getting the driver side head off, I have pulling injectors down to an art now......
Also, anyone have a diagram of where this shim would be in the head, looked all over but don't really know where I need to look either.

[justinlogue5_0]

Originally Posted by roccodart440

Looks like a valve spring shim to me. VS retainers are like a half moon wedge type of thing. It definitly isn't one of them not to mention you would have dropped a valve.

A shim on the other hand would give you less seat pressure and thus lower compression.