I have a 99 malibu 3.1 engine :banghead: ,I did a head gasket job on it ,# 1 and # 3 cylinders have no compression due to the lifters on the exhaust side not releasing the oil from them (if I swap a lifter from another cylinder it will work fine and the one that I put on the # 1 or # 3 cylinder will not work)
I tried putting a washer under the rocker arm and the compression is over 150 psi,the machine shop couldn't figure it out,,may be someone out there have had this problem,,,if so please let me know ,,thanks in advance :banghead:

Aren't the pushrods different lengths? I read somewhere it was easy to mix up the pushrods due to the length difference's.

I agree with wymi, check the pushrods, also does everything look o.k. withthe heads? Are they assembled correctly?

the push rods are in the right place long for exhaust and short for intake,the problem is with the lifters not purging the oil ,, in the # 1 and # 3 cylinders only,tus becoming hard and always pushing the valve in the open position, if I unscrew the rocker arm screw just a couple of turns I will have high compression but the engine will have hard missfire and i will get a multiple cylinder missfire on my scanner.:banghead:

So if you put a lifter from #1 or #3 in another location that lifter works fine? If so, maybe something in the lifter hole's on #1 & #3 won't let the oil drain out, blocked oil passage maybe?

I spray all of them with carb cleaner - every hole.