ahritchie

iTrader: (1)

So I'm on my 2nd LT1 and just my luck, my brand new 383 has the classic LT1 rear intake manifold oil leak This is not my first time dealing with this as my old LT1 did the same thing until we pulled the intake and replaced the gaskets/rtv. I'm planning on pulling the intake and putting in new gaskets this weekend. Are there any helpful tips/suggestions to ensure it does not leak again Or is it just a hit or miss type deal?

BTC

Arc welding?

wrd1972

iTrader: (12)

Just use the RIGHT STUFF RTV.
Done.

ahritchie

iTrader: (1)

lol good idea

ahritchie

iTrader: (1)

Last time I used Permatex "ultra black" gasket maker.....is "Right Stuff" a better formula RTV or something?

Z28Roxy

iTrader: (4)

Yes. I used the right stuff and mine never leaked after.

RamAir95TA

iTrader: (2)

I've always used Ultra Black but next time I might give The Right Stuff a shot. Seems to be pretty popular nowadays.

whytryz28

iTrader: (28)

This stuff is close to impossible to get off once it dries. Have to cut it off then sand it down.

SilverSS07

iTrader: (1)

I used the ultra copper RTV and haven't had a problem yet.

defaultexistence

iTrader: (11)

Ultra grey by permatex (reccomended by Lloyd elliott) , make a bead front and back, let it get tacky,set intake straight down,torque, let sit over night, retorque, after a week retorque.. Best results IMO

nitrous2fast

iTrader: (2)

The right way to make it not leak is to put the manifold on and see how high the sealant needs to be to make a seal. Not all manifolds have the same size gap to fill. Any kind of change to the heads/intake/deck will make the size change.

ahritchie

iTrader: (1)

Good suggestions here....will try "test fitting" the intake and see how big a gap there is and re-torquing the bolts overnight and maybe a week later; I don't think I did that last time.

BALLSS

FWIW I have always used the black "ultra" RTV. Surface mating and really cleaning it are important so as suggested confirm the intake manifold sits right. On 383 builds the heads, block have been machined and this effects how the intake manifold sits.

also let the rtv cure overnight before starting motor

Badazz 97 TA

iTrader: (18)

Clean the surfaces real well and set the manifold straight down on the bolt holes. Dont let it move around. Its nice to have another person there to help set it in place. Torque it down and Let it dry over night. I run the sealant up on the head about an inch to where it overlaps the actual intake gasket.

Ive used the permatex copper and just the normal black stuff with good luck. no leaks.

ahritchie

iTrader: (1)

I'm about to burn this car to the ground After pulling the intake TWICE this weekend I STILL have an oil leak. I do know however the causes of failure of a couple intake leaks though; the first time Saturday me and my mechanic friend pulled the intake, after scraping the old RTV off the back, there was damn plastic tape of some sort taped to the edge of the block where the intake seals to it...maybe the engine builder left it WTF So the oil was leaking under the tape/RTV.

Then, once we were ready to put the intake back on with new RTV, I was fumbling get the wiring harness, and EGR pipe out of the way my finger touched the fresh RTV....I told my buddy we need to pull the intake back out and re-check the bead because I touched it...he assures me he put a BIG bead of "Right stuff" and not worry....LMAO...MISTAKE.

So we pulled it again (taking only 2 hrs this time lol) and CAREFULLY placed the intake down after pulling the whole wiring harness out of the way.

Today I had two small oil puddles on my driveway I put my hand on the back of the motor and felt the oil pressure sensor fitting the sensor screws into is coated in fresh oil....I did replace the oil pressure sensor a couple weeks ago, it had a little white thread sealant tape on the end that screws in, but I didn't use any pipe dope...could me NOT using pipe dope on that cause a bad leak? It's a pretty decent leak as I could see it dripping on my driveway as the car idled at operating temp

RamAir95TA

iTrader: (2)

The oil pressure fittings are both subject to 60+psi of oil pressure so applying NEW thread sealant is highly recommended. Personally I prefer a non-hardening paste - not thread tape.

SS RRR

iTrader: (2)

Did you use any kind of thread sealant? Did you let the sealant for the manifold completely cure before starting the engine?

ahritchie

iTrader: (1)

Nope....there was just 2-3mm of white thread "tape" already on the autozone oil pressure sensor, I just screwed it in as is; now that I think about it it took a couple minutes to position it to thread correctly trying to screw it in the fitting...maybe it rubbed off. I will get some pipe dope and dope the crap out of it tonight and see what happens.

Believe it or not, the directions for the "right stuff" say you can put the vehicle right back into service after it cures in less than 1 hour....the regular "ultra black" does say 24 hrs. We waited 24hrs the first time....but that was botched due to my finger lol. 2nd time we put it on just waited 2 hrs.....it didn't leak after a 30 mile drive, but now it is all over my driveway the following day.

ahritchie

iTrader: (1)

Are you saying it's recommended to take both fittings off completely and put new sealant on them (not just the oil pressure sending unit?)

Is this possible to do without removing the intake AGAIN lol?

BTC

I did not use any additional sealant when I replaced my oil pressure sensor, and it did not leak. I used an AC/Delco sensor. I'm not sure whether that might make a difference.