94adam89

Hi everyone! I recently purchased a 95 z28 with a blown drivers side head gasket. Long story short, one head and a hole bunch of gaskets later I had her running again. Ive been driving the car for about 4 days and have developed a MAJOR oil leak! The leak is definetly on the passenger side. I pukked the balve cover tonight and it was clearly not the leak. After looking some more it appears the leak is coming from under or near the #6 cylinder headgasket area. The whole side of the block is soaked. At an idle there is no leak, but if free reving at 3k rpm, will begin to leak a steady stream in as little as 5 seconds. But after returning to idle the leak slowly dies off. What te hecks up with that? The is a serious leak. Not a few drops but enough to fill about a half an inch in the bottom of a soda bottle in maybe 15-20 seconds? Btw, I also replaced the intake throttle body, headgaskets, exhaust gaskets. Intake seals, valve job. Heads surfaced and pressure tested. Any help would be great thanks!!!!!

Camaro350z28

dipstick tube in all the way?

94adam89

Yeah its in all the way. Anyone know how its sealed from the factory? I assume it had an o ring, but it didnt have one when I pulled it out. I used rtv on reassembly.


Doing what I like and not what I should!

Injuneer

Sounds like you may have excessive piston ring blowby pressuring the crankcase, and blowing oil out of the dipstick. Check the PCV valve.

94adam89

I put a new pcv valve in it also. I can tell that its not leaking around the dipstick, although I wish it was. It honestly looks like its shooting right out of the passenger rear corner of the head.


Doing what I like and not what I should!

pizzi-man

Could be coming from the back of the intake manifold down the side of the head and all over the starter

94adam89

That crossed my mind too, but I cant imagine that it is now. I took a paper towel and rubbed around behind the intake and around the top part of the bellhousing and there was nothing! Plus, the way I see it I cant see how that much oil could run out when the intake is that high. Even if the crankcase was holding alot of pressure im sure it could never push the amount im leaking.


Doing what I like and not what I should!

pizzi-man

The head has no oil pressure or oil passages where it meets the block. The head is oiled through the push rods.

94adam89

I understand there is no pressurized oil, but arent there passages in the corners of each head to drain some of the oil too? I know some drains back down into the valley.


Doing what I like and not what I should!

pizzi-man

yes there are and they drain back to the valley not to the side of the block and yes you can loose a bunch of oil with a leak in the back at the china wall where the manifold, head and block meet. did you run sealant behind and on top of the intake gaskets at that point?

94adam89

I ran a bead along that wall in the back and slightly onto the narrow part of the bottom of the intake gasket where it meets that wall. Tomorrow I plan to pull the passenger exhaust manifold of and clean and inspect the area where the block meets head. Also going to retorque all headbolts. Its so hard to see around the back to check for leaks!


Doing what I like and not what I should!

Scrub88

I no you said you checked dipstick tube .. . But I had a massive leak in the same area bought a new tube . That was were it was coming from .. Got it seated pretty well down to the little lip around the tube . Still had to get rtv on my finger and wipe all around the flange on the tube stopped its leak ...this was a new gm part

slick1hunting

if you havent tried an inspection mirror would be worth the money probably. I would eliminate intake leak(rear) dipstick and even the oil sender(yes its on the wrong side but if its squirting under higher revs could shoot to passenger side).Then I would clean and dry areas from every angle then start it up and run it for a few looking with mirror and everything I could see.Then before got hot I would shut it down and wipe for oil and see if that helped determine a location to focus on


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94adam89

Thanks everyone for the help. Tonight I bought dye for my oil and a uv light. I ran it till I saw the leak develop and then checked with the light. Clearly it was running down the bell housing. So I pulled the intake and found that I had nowhere near enough rtv in the back. I will be going much heavier with my next bead! Thanks again everyone!


Doing what I like and not what I should!

pizzi-man

do your self a favor and clean the intake seal area with lacquer thinner along with the china wall. let the RTV sealant sit for like 10 minutes before you set the manifold and let it sit for a day before you drive it.