Well Ive been chasing a cylinder 4 misfire for a couple weeks. Last night i borrowed a compression tool from a freind only had time to check #2 and #4

#2 Pumped up to 150 but then bled down

#4 Pumped up to 55 but bled down to 0 in 10 seconds

I dont think i had a good seal on the comp tool couldnt get down the spark plug sleeves to tighten it. wonder if thats why it was leaking down so fast

gonna check all cyl this weekend

 

Could be cracked valve seats, which are common on stock heads. The aftermarket replacements are much beefier.

 

Think im about to get a set of rhs x heads

 

I guess ive been one of the lucky ones. Ive got 300,000 miles on my stock 5.9l heads and hit 150 across all cylinders on my compression test last week.

 

Well thats just special J/p congrats man i think i hurt mine when i blew the head gasket last month. Like a MORON I didnt check the head (was in a hurry to get back to vacation)

 

I think that just means you drive like my grandma.