Ok so I was driving tonight and was WOT in 4th gear.. Black smoke started going everywhere but not from my tail pipes. The smoke was coming from the engine bay where there was a breather in the passenger side valve cover. Oil was shooting out pretty nicely.. Any how as soon as I saw the smoke I turned it off and turned into a parking lot. I called a tow truck and brought the car home.. added some oil back to the right level and started it up.. starts up and sounds perfect.. vacume is good, fuel pressure, ETC. I pulled the breather out and held my hand over the hole and there was no pressure against my hand. I dont get it. the car seems fine now.. I think its boost related.. WOT i was at about 7PSI and rising when the smoke started.. free revving I dont see that much boost.. Im thinking I blew my intake gasket. A few people have told me it highly unlikely.. The oil looks perfect and the coolant level is normal and the color is fine.. I dont get it.. anyone have any ideas????


Thanks
Nick

 

If it only acts crazy when the engine is under boost, take the blower off. ROFL.

Nah, I don't know, bro, because I have very limited knowledge about troubleshooting blown cars, but maybe it has something to do with excessive crankcase pressure from bad rings?

Mike

 

Anyone think it could be a blown intake gasket.. the bottom end is fully built and has forged everything..

 

Might wanna post this in the Forced Inducton section.

 

Is the vent hose that goes to the passenger side valve cover still connected to the throttle body? If so then it will presurize the crank case under boost.

Ben

 

No.. that hose is not connected.. there is a breather on the valve cover...

 

Well, pressure is getting in there somehow. It's going to be either past the intake gasket, or past the rings. I would go ahead and pull the intake and check it since it's so easy to do. I would also recommend doinga compression check to see if you have a potential broken ring land or ring.

Just off the cuff, I would bet on pushing out the center portion of the intake gasket between the siameased center runners.

Get wrenching and let us know what it is!

Dave C.

 

I started it up today since yesterday I didnt even want to look at it.. well it seems like a ring or something.. at idle I cant feel air blowing out of the filler neck but when I revv it up I can feel small puffs.. I dont think thats its very normal.. I dont know.. How could a piston ring have broken? or a ring land? Im only pushing like 10psi and the pistons are forged with some pretty good rings.. ugh...

 

Oh yea.. and when I held the RPMs at like 3k so I could feel the air I also noticed all of the headers turned orange... thats some serious heat.

 

Well, that isn't good.. I still say pull that intake manifold off and see if the gasket let go. I tend to be an optimist though

As tot he ring land.. Could be any of a number of things. If you lose a ring land on one piston and all the others look good, and you arent detonating, then I would tend to think it had a problem before it was installed. Something like a tiny crack in the piston top at the land or something like that. Or, if they are dished for the low compression, the valve reliefs cut into the top can make the material at the edge pretty thin with big valves. Also, you could have had a piston ring expand too much and butt ends which would be very bad to the life of the piston. Like said, any number of things..

Pull that manifold and do a leakdown! Only way to know for sure man..

Dave C.

 

Im going to do the compression test and leak down test before I pull the manifold.. Is it normal to feel a bit of air out of the crank case? I dont feel any air at idle...

 

 

Cars fine.. I made the PCV valve go crooked and let boost in the oil system.. Cars fine.. drives normal and all. No air coming out of the valve cover or anything. Still doing a compression test tomorrow..

 

Pull it down and bore,pistons,and rings. If a ring is broke(more likely a ring land on the piston) and you keep runing it it will TEAR up a cyl wall. There is probably more than 1 cyl hurt.