When I took my valve cover off I thought it was on awfully tight, but when I finally got around to retightening them I get to the very last bolt and hand tighten it then turn it with the wrench and SNAP. Its the bolt closest to the firewall. Its sticking out enough to where I can get some needle nosenose pliars on it but not enough to get grip to turn it.

I had extra valve cover bolts and replaced the other 3 (they both had marks on them that looks like they were over torqued at some point.) Now I have that broken one. I drove the car around to test if the rocker arm was repaired and the car ran ok but at idle it sometimes would huff and puff like it had a vacuum leak (the valve cover I assume.) Am I ok to drive it around until I can find a way to get this stupid bolt out? Was the last damn bolt!!!

 

Took the car for another drive and it stalls sometimes. I'm guessing vacuum leak

 

it shouldn't be stalling

Lots of guys drive around with cracked/broken pcv lines, which is essentially the same thing

It shouldn't cause stalling, especially from a small hole like that

 

It runs well and then it sputters and tries to stall like there is a huge vacuum leak. The only thing I did was installed a new rocker and that was pretty straight forward. What I am thinking is the screw that bolts into the valve cover has a grommet around it and perhaps its not sealing now that the screw has been snapped? There is a small amount of oil leaking out the valve cover too so I am sure its not sealing well. Other than that the car feels great now that the new rocker is installed. Nice and smooth but like I said it tries to stall when the RPM's drop like it has a huge leak.

 

LS1 Corvette FYI.

 

Yeah, but a vacuum leak would be the intake manifold which would be letting unmetered air into the engine.

A small hole in the valve cover is not creating the same thing as a hole in the Intake..

Many people put breather filters, homemade catch cans without a pcv valve etc on the valve covers, Which is the same as an open hole to atmosphere

It shouldn't cause it to stall out though since all you are doing is venting the crankcase pressure by having a hole..

 

I would try cleaning your maf sensor, it will cause poor idling and it will stall the car out if it's dirty..

Auto parts stores sell a can of maf cleaner and its a good place to start, also check the brake booster line and all lines going into the intake manifold.. Make sure everything is connected

 

The car ran fine other than a tick before this though. It was a bad rocker but the car idled perfectly fine. The nasty idle started only when the valve cover was taken off. Short of the rocker arm install going bad, but again when on the throttle the car runs fine, I haven't hit boost yet though. Its idling like it has a major vacuum leak. Nothing on the intake was touched. The only hose unplugged was the top hose going into the valve cover, the second hose is capped off, and my oil cap is a modified cap used by an A&A Supercharger. The only thing that makes sense to me is there is a crappy seal somewhere. FYI this is passenger side. From what I am gathering here a bad valve cover seal shouldn't impact vacuum?

 

My setup looks exactly like this.

 

Why replace a rocker? Maybe deeper damage..

 

Something is wrong. What caused the rocker damage? Is the push-rod bent? Is the lifter damaged? Did the damage crack the head/ damage spring? These are the things you need to be looking for before driving the car around.

 

Weld a nut to the end of the broken bolt. Or, grip it with Vice-Grip pliers.

As for the poor running, that's a different issue. You probably left a vacuum line unplugged, or an old one cracked.

 

Yea, not sure about the bad running issue, but I guarantee you its not the broken bolt. There is NO vacuum in an internal combustion engine. It would run fine without the valve cover on the engine at all. It would splash some oil around and make a mess but it will run fine. Engines actually create positive pressure due to piston ring blow by. All engines leak a little pressure past the rings due to the rings are never set to zero gap. They need room to expand and move. This is what a PCV valve does. Its stands for positive crankcase ventilation. Meaning the intake actually pulls a vacuum against the engine at the valve cover to relieve this positive pressure inside the engine and takes the oil vapor that is created and puts into the cylinders to be fired and sent out the exhaust.

So, you have another issue. A hose could have cracked or split. You could have moved something when working with that head. Or just a complete coincidence that something went bad when you worked on another part. It happens.

 

I had a bad bearing in the rocker arm.

Ill give it a once over again and see what I can find!

 

Corvette Gremlins strike again! Took it back apart and put it back together. Drove it around and she's driving great. Idling around 500-750RPM with a slight gurgle (from my cam I am assuming.) The only thing I can think of is maybe I didn't push the coil plug in all the way somewhere? Anyways! Thanks everyone for the help.

 

Idk a loose coil would of triggered a check engine light.. Or maybe not

Anyway glad you fixed it

 

yup. just make sure to disconnect the pcm and bcm first.

 

Could it possibly have taken a few heat cycles for the rocker to settle? I am just super baffled by this and since I am going back to do the trunion update I am just looking to avoid any foolish mistakes.

Also I am getting a lot of oil blow through on the engine worth a catch can????

Thanks guys you rock.

 

once the rocker is torqued to 22 ft lbs making sure the lifter is on the base of the cam then you are done..

No heat cycles needed

Yes a catch can is a good idea

 

I will look into that! I am going to do the Trunion upgrade and grab some push rods also at the same time.

Once again guys life savers!