Question for the motor smart guys? or anyone else!

6uldv8 · Dec 19, 2007

Friends truck 99' Chevrolet 5.7 Vortec ran hot last night.....he shut it down quick and got it home. We were expecting the usual water pump or hose or radiator etc..... to be the problem but it wasn't. If you are facing the front of the motor....the seam(on the drivers side) where the intake and block meet together almost at the edge where the head joins them is leaking like a mofo! It blows out instantly when you crank the motor I assume from just direct water pump pressure because it doesn't even have to heat up to start pumping out. I'm only slightly familiar with the old style 350 block and intake but I would think in that area if water were pumping out the front that it would also be pumping into the inside and into the oil...BUT.....there is no water in the oil YET.....I haven't a clue where all the water paths on this thing are but it just seems odd to be coming out that seam. Anybody familiar with this motor....does it sound like just a pull the intake and add gooey gasket fix or does it sound more serious? We'll be pulling the intake tonight but just wondered if any of you had encountered this before.

P · Dec 19, 2007

All I know is intake gaskets are very comin issue's with those motors. I think your on the right path.

Did this motor blow any kinda smoke or anything ? ( burning off the water in the cylinder / cylinders were the intake would be leaking ?)

6uldv8 · Dec 19, 2007

hmmmm....dunno about the smoke...I know it hasn't up til now....but I'm not sure what happened last night when this thing drained itself.

Jeep CJ · Dec 19, 2007

Should just be a gasket problem have seen the same thing several times. Like P said common problem on those motors

6uldv8 · Dec 19, 2007

We hope so.....just can't figure out how the water is getting to where it's pumping out....it's actually coming from between the intake and block but very close to where the head gasket starts. We'll see soon enough I guess.

87yjtoy · Dec 19, 2007

I'm not positive but that motor has a two piece intake manifold. The top half is plastic and the bottom half is aluminum. Bottom torques just like the old style and the top half torque spec is about 25 inch pounds IIRC. I replaced a few of these but it has been several years ago.
Good luck, just dont over torque the top part.

6uldv8 · Dec 20, 2007

You are exactly right! Top half is plastic! I'm thinking he won't allow me to help with that part! lol

blacksheep10 · Dec 20, 2007

extremely common. the intake (bottom half) has 5/16" bolts, not teh 3/8" the old ones had. this means that the spec isn't 30 ft/lbs anymore. ask cash talks how he knows laughing

. I'm talking like 8 or 10 pounds at most. the water passage that goes to the tstat housing is on front of the intake, so it is going towards the front and down towards the block. lucky its coming out, not going in the lifter valley.

funny thing is that I've had the intake off my vortec 8 times now from head swaps (musical vortecs on my motors) and have never had a leak ???

6uldv8 · Dec 20, 2007

Thanks Kelly....that water path was what had me wondering. Guess we'll be pulling this thing this weekend. Thanks guys.....I knew yall would know what was happening!