I have just blown off my 3rd oil fill cap. Has this happened to anyone else? I know its on tight when i put it on. I was thinking it has something to do with the boost pressure, but not sure.

 

Umm... that's not good, you either don't have adequate crank case ventilation thought the PCV system, or you have a blow by problem. Defiently needs some looking into.

 

There is no blow-by that i can see. And the 8.1L's dont have a PCV valve, they are integral. What should i do? What should i be looking for?

 

IMO, Compression or leak down test not check for bad rings.

 

No't sure what issues your having, probably whats been stated already but I had many issues with the oil cap and even the dipstick blowing out under boost. I finally solved it with a home-made venting system.
I alsoo took my oil fill neck off and attached the cap right to the valve cover, it fits a lot tighter this way. Don't know if the 8.1's fill cap has the same thing though.

 

I would assume if it was a ring/piston issue, i would be seeing some performance problems. I dont have any performance issues at all.

 

Well the 8.1L has the oil tube coming out of the intake manifold, not the valve cover, so i cant go that route. Should this be a serious concern? If it is, i dont want to jeopardize the engine over it. I will pull the blower off and do some N/A mods if thats the case. I was trying to get some ideas why this would be happening, if the only answers i get are the kind that sound like i may be putting the engine at risk....i may have to rethink a few things here. I am not in the position to do any major engine work here, just trying to have a little fun.

 

yea i have the same issue when i get on it on the freeway my oil cap comes off and blow all the oil all over. if it would be ur rings or piston you would notice performance wise and a big miss. have all three oil caps come blow off in the same situation?

 

my oil cap came loose once and oil leaked on my exhaust manifold and i had a fire! Talk about shitting your pants. All i had was my shirt to try and put it out. I got lucky, just melted a plug wire and burnt my hand. I Then bought a Billet oil cap from Blue01 and Never had the problem again but i also had my pvc switch valve wired wrong. I would ask Blue01 for a cap. It will have a 1/4 '' tapping in it, so you could adapt some type of breather on top the cap. good Luck.

 

I'm with above. Get an aftermarket oil cap breather. Then get you an oil catch can. It will catch any excessive oil that will try and build up in the intake manifold. I think these two mods will be your fix.

Jim