Low compression questions and problems

[Ecomike]

Well the last 4 weeks of December 2008, the rough idle came back, worse than before, and the CEL misfire Cyl 1 came back and stayed. So we pulled the heads over the Christmas holidays. Machine shop found hairline cracks in both heads. So we replaced the heads. Found some pitted spots here and there in the cylinder walls of the #3 cylinder near the top, suspect there may have been more lower down in other cylinders which might explain why the Restore helped out. Head gasket was OK. The rockers and tappets looked brand new, so someone had done a prior engine job before he bought the beast.

The worst head crack was at the valve seat area. The oil seal and valve guide on Cyl #1 finally gave out and fouled the #1 spark plug and cylinder. In summary, he got 20,000 miles out of it before we finally changed the heads.

 

[Ecomike]

One final update to this story. After replacing the heads last week, and getting the most unpleasant and persistent # 5 cyl missfire code, trying a different fuel injector, checking for spark....then finally In one last desperate cheap attempt I replaced the spark plug. Bingo! No more more worries. I was just about to pull the heads, or at least dig into the rockers and lifters again.

The old Spark plug looked great, it was a Motorcraft single platinum tip, so were the rest as well as the new one. Must be something internally out of whack with the bad plug.

Long story short, it's a 200,000 miles and back on the road.