I recently replaced the intake gaskets on a 1995 3.1l Corsica. I used the improved Fel-pro intake gasket set and the supplied black RTV for the space between the heads. I used a pushrod removal tool to compress the valve springs without removing the rockers. The car started back up without issue and idled fine, got the air burped out of the coolant system, brought it up to temp, let it cool down, rechecked fluid levels, everything seemed fine. Took it for a test drive, everything seemed good, even took it on the interstate and got it up to 70mph without issue. When I got it back home, I turned off the engine and checked fluid levels again. When I started it back up I gave it some gas and let off the throttle, that's when I heard four pops coming from the exhaust. It seems to idle fine and revs up fine, but pops four times when the throttle is released. Any idea what I could have screwed up? I can't seem to figure out why it ran fine for 20 minutes then started this. The noise is very clearly coming from the tailpipe, the valvetrain isn't noisy or anything like that.

Additional info: The car had been running fine for the most part, I discovered low coolant when the heat stopped working, the oil was contaminated, but still mostly resembled oil. When I did this job I also replaced the o-rings on the dummy distributor shaft and used RTV to seal it at the block. I put new fuel injector o-rings on as well. I did use a torque wrench when installing the manifolds. Everything seemed to go together without a hitch. The only mistake I know I made was when using the pushrod removal tool, I did slip off of one of the rockers, which slammed shut at near full spring compression.

 

Just took the car out after letting it sit overnight and the issue when away? I'm wondering if some carbon deposits broke free and were causing problems. Gonna run some seafoam through the intake tonight for the hell of it. I'm stumped.

 

The issue did show back up, it seems the engine has to be warm for it to occur, which just confuses me even more. It does seem less pronounce than it did last night.

 

Aren’t you supposed to re-torque the heads after a warm up?

 

I didn't do the heads, just the upper and lower intake manifolds.

 

Sorry misread.

but maybe you need to.

 

You probably need to re-torque the rocker arms. I've done this twice now on my 3.1 lumina. Since I read you have experience with this, just "run " the rocker arms with each valve on top, then give the rocker arm about .010" inch clearance.

 

What I do with rocker arms, with the valve fully closed, I take the rocker arm, and "shake it". If it moves side to side without a lot of slack, I call it good.

 

No worries, I appreciate the input nonetheless. I considered pulling the heads since I had already done the hard part ( getting to them) but didn't want the car to be down long enough to send them to the machine shop. I should also add that the cylinders all seemed good when I did a compression check, which is another reason why I left the heads alone.

 

Two questions. Do you think the rockers could need adjustment even though I did not remove them? Can you adjust the rockers with just the valve covers off or does this involve pulling the intake?