#4 misfire and oil on spark plugs

[00yukon]

can anyone help me out #4 cylinder is misfire and there is some oil on the almost all the spark plugs. 5.7 vortec 97 tahoe

can someone tell me what this might be.
it might be time to replace this tired 5.7 with a 5.3

 

[SunlitComet]

Either you have worn valve guides and/or seals or you rings are giving out. A compression test is in order.

---------- Post added at 03:30 PM ---------- Previous post was at 03:28 PM ----------

A NEW tinned long block is only $1800 at jegs. Stock replacement with all new parts.

 

[blueflamed03]

yup, oil on plugs, not good.

 

[99Yuk]

Oil on two of my plugs are what pushed me into buying my crate motor from a GM dealer in the first place.
I was consuming a litre a week of oil, replacing those two plugs once a week, and had a bad misfire.


Valve seals are cheap. I tried replacing all of mine to see if the problem would go away. It didn't. But it may work for you. And it's a less $$$ item to try.


Good Luck!