CRUSIN1

I’m ready to fix the intake manifold leak after many years of “kicking-the-can-down-the-road”. I’ve own this 1992 corvette for sixteen years and only has 25,288 miles on it. I’m sad to say it, but I’ve only put 5,100 miles on it in 12 years. This corvette is UNMOLESTED, garaged kept all its life and looks as if it rolled off the assembly line yesterday. I did a major engine cleaning job with rags, blush and compressed air over the weekend. It’s clear that the intake manifold is leaking oil in the front and some in the back.
I have read & studied many of the posts about replacing the intake gaskets and the do’s & don’ts on doing this project. Please offer any advice as I will post status photos of my repair.

I added pictures of the untouched engine. Please add any & all comments, my fellow LT1 engine folks, please chime in.






1992 LT1 with 25,288 miles, engine unmolested.














driver side intake manifold, note fuel injectors





oil leak, front, above water pump

jmgtp

Advice: when you pull the coolant lines off the throttlebody be sure not to spill any coolant on the optispark. I used the Right Stuff to seal the front/back walls of the intake. Though most gasket kits come with a u be of sealant that will work.

It's not a hard job, just take your time and keep everything clean.

Motor looks great.

WW7

I agree with the suggestion above, use "The Right Stuff" as sealant and you won't have to mess with it again for many many years...Make sure you use the proper torque seqence when bolting down the intake, also take the bolts down in increments going around the bolts 3 times, each time at a higher torque setting...Make sure you place the intake down perfectly square so it lines up on the first try, you don't want to have to shift is around once it's installed..It's imperative that you clean all surfaces completely, anything left on the heads or intake can cause a leak, I use laquer thinners to wipe down all surfaces before installation....Put thread locker or teflon paste on the intake bolt threads to seal against oil leakage, I like the teflon paste best because you can go back a few hours later and retorque the bolts...Don't start the engine until the next day, this gives the sealants enough time to set up completely..My engine is the L98 ,but everything I mentioned above should also apply to the LT1 engine .....If I think of anything else I'll post it later..Good Luck......WW

CRUSIN1

Thanks for the advice WW7, I have read many of your chimes in other threads. What advice for the fuel rack and injector O-rings installation?

CRUSIN1

Hey jmgtp.... I was not going to disconnect the coolant lines from the throttle body, just remove the 4 mount bolts, pull to the right side and zip tie for temp mounting? What's your thoughts'?

WW7

You need to use a lube on the O-rings to stop them from rolling over and sticking while installing them...I use Vaseline on the O-rings to lube them, but a lot of guys on here use motor oil with good results.I also put a little on my finger and wipe it in the injector bores in the manifold just to make sure the O-rings don't stick going in.....Jon at FIC says to install the injectors in the fuel rail first, then push them into the manifold..Those look like the stock injectors.. If your not in to big of a hurry to put the car back together, it might be a good idea to send the injectors off to "Jon at FIC" and have them cleaned and tested...Just a thought........WW

CRUSIN1

Started the project this morning, I removed the throttle body bolts and moved it over to the right side with the coolant lines still attached. Removed the bolts and the complete intake manifold came off and out without ANY resistance. Note the picture of the oil just lying on the china wall area. I must say the front 2 bolts weren’t very tight at all. It took about 4 hours to clean up the gasket areas and fuel rack/ replacing the injector o-rings. I’m letting the “right stuff permatex dry overnight, then put it all back together in the morning. We post the results tomorrow.











backside of engine