I have a cylinder 7 misfire and it happened a month ago then went away, now its back and the truck is running rough. I made sure the coil pack and plug were fine and brought it to the local mechanic who told me there was no compression in cylinder 7. I brought the truck home today and pulled the valve cover and noticed everything was coated in burnt oil. when i pulled the lifters and rods out of #7 there was caked up burnt oil on the rods. Any ideas?Vehicle has 120,000mls

 

depending on the year and engine type...cylinder 7 is a afm cylinder. crank it over and see if the rocker arms moving for that cylinder. if not, the afm lifter has collapsed.

 

After tearing it down I found the collapsed lifter. Ty very much

 

After I pulled the suspect lifter I could compress it a half inch. After working it a bit it won't compress much. Any ideas why? Was it just gunked up?

 

did you run it low on oil?
what is your oil change interval?


install all new afm lifter on that bank, do both is you have both sides apart.

 

I change my oil religiously and always check it. What I did notice when I tore the top end apart was the driver Side of the valves were caked with burnt oil and the passenger side was golden. I believe I just had a stuck lifter which sucks because I could of just done an engine flush instead of a rebuild. Live and learn I guess.