(92 LT-1)I have been told by the GM dealer that I need to replace my intake manifold gasket. It appears from what I can see that is what it needs done. Its leaking oil all over the back of my engine, exhaust, and clutch. They want $125 for the gasket and $750 in labor to to this. Im going to opt to do it my self. I just have a couple questions.

1: How much does a GOOD gasket actually cost and what is a good site to order from?

1 and 1/2: is the the gasket a gasket set or just one gasket?

2:Is there any site that offers some assistance maybe with some pics and steps just for some extra confidence in doing this?

3:What are the torque specs or where can I find them to torque properly?

4: Will there be any SURPRISE items I should be aware of? (I don't need to be there again

Please any help would be greatly appreciated.

 

You don't want to do this job unless you have the factory manual, which will answer your torque questions. Any gasket from the local chains should be fine, it isn't the gasket that is causing the oil leak. It is the goop they put on the front and rear of the intake that gets blown out and leaks oil from the galley. Make sure these surfaces are thorougly clean, and use "The Right Stuff". NAPA carries it, so do many others no doubt. I think you should let it set for 24 hours before starting the engine.

 

A Hayne's manual is adequate for this job IMO.

 

This is where the FSM will more than pay for itself; order one from HELM before you start.

Pick up a top end Fel Pro gasket set at AutoZone (~$35 for my L98) and go for it.

On my L98 the set provides all gaskets needed to remove/replace the intake including the base. It even comes with a small tube of black RTV.

Lotta guys here prefer the Right Stuff instead of RTV though the latter has worked well for me.

I can't help with the top end details of the LT1 but can with properly sealing between the base & engine lands as well as heads.

 

Maybe so but the FSM is the real deal and this is but one example of the payback from it...

 

Here is a good thread. There are lots in the archives

http://forums.corvetteforum.com/show...et+replacement

Good Luck

 

I just completed this job on my 92. I do not feel that you need the mannual as there is plenty of info on the net. I found a complete write up with pics on a camaro site. Just google lt1 intake manifold gasket replacement. After doing mine, 125 for gaskets and 750 for labor sounds like a major ripoff its not that hard to do.

 

Definately the wrong suggestion.... Haynes are only good for door stops, not corvettes

 

Like I said, it's just my opinion. The Haynes has worked out fine for me for intake, heads, cam, etc. The FSM is obviously a better choice.

 

Do not for any reason crank the car until at least 24 hours after you bolt the intake back on. That is, unless you can't wait to do the job all over again. I learned this years ago the hard way, and had to pull a Super Ram twice.

 

Its far easier than you think...and it gets easier everytime you work on an engine.The L98 TPI is more complicated but got so easy after the 2nd time I did some work on other engines.

One thing that gets me...you said 750 for labor...wow,whats the labor rate and how many hours for the job?Im just curious.

It does not take that long for a experienced tech to do the job and I cant imagine why 7 hours is required,unless they are using book labor quotes.

 

Once the manifold is off plug up the intake ports with shop towels to keep old gasket material from falling in. Scotchbrite pad on a die grinder works great and is quick on gasket removal. The FSM was a must, more specific specs, and diagrams. Go slow, mark every intake bolt with masking tape and numbers. Draw a hole diagram on paper with corresponding numbers. My L98 bolts were all differant lengths, this was crucial. Hand start all bolts so as not strip them. Good Luck !

 

BTW, you should also blow the crud off the intake above where it meets the block with compressed air before removing the manifold and exposing the engine galley. Otherwise, any collected debris will fall into the oil and likely compound your problems.

 

Good Lord, those prices are criminal

1) By the GM or Felpro gasket kit. ~$35 from Chris May at Superior Chevrolet (forum sponsor, be sure to tell them) for the GM kit or about the same for the Fel Pro kit from Summit, Jegs, etc. FWIW I like the GM stuff The "kit" will come with the two gaskets (one/side) that fit between the intake and the cylinder heads. The end seals are RTV. The Right Stuff is good, as is the FelPro brand of RTV.

2) Not that I'm aware of, but it's not a big deal to do. The LT1 intake is dry, so you don't need to drain the coolant (there is coolant that runs thru the throttle body, but those lines are easy to cap as you remove them). Book time is ~4 hours.

3) On my '96 it's 35 Lb/ft as I recall. Your '92 may be different. This is where a real service manual pays for itself. You also have to torque the bolts in sequence.

4) No need to remove the fuel injectors from the fuel rail. Just unbolt the rail from the intake and then lay the whole assembly on the windshield on a towel. Be sure to clean/vacuum around the edges of the intake before pulling it off to keep debris from falling into the ports or lifter valley. Use ****new**** razor blades (I typically use 1/side) to remove the old RTV and gasket material...it makes it soooooo much easier.

If it's never been apart, you'll need a new throttle body to intake gasket, as well as a gasket for the EGR valve and the AIR tube. Should also probably replace the o-rings that go around the injector tips (this is why it's easier to just order all the stuff from Superior versus trying to source it all over the place) Good time to replace the pcv valve. Be careful with the plastic vacuum lines and check valves...they get old and brittle.

 

Parts needed:
Intake manifold gasket set, EGR valve gasket, AIR tube gasket, Valve cover seals (gaskets), Throttle body gasket, Injector "O" rings.

The success of this job will depend on the quality of the bead of silicone you apply to each "china" rail before the manifold is set in place. It is extremely important that the block and manifold end surfaces and the corner crevices are very clean and dry before applying silicone. Acetone, lacquer thinner or brake cleaner works well for this. Try to run a continuous even bead of silicone about .200 diameter with a small additional amount in each corner. I usually put a dab in the corners first before running the bead. Let it cure for 24 hours before starting the engine.

 

I did mine after having the car for 2 weeks and not knowing squat about it. You really don't need any manual to tell you to unbolt all the sh** in the way.

 

Wow some good responses. I feel a hell of a lot better now about doing this job. Ill definatily take all of this info into consideration. I will probably get a manual for proper specs and stuff as well just to have one to have one. Its something any do it your selfer should have anyway.

Some one asked about how the dealer priced me for $125 and $750. Well Im in Germany and Everything here is expensive. It would be even mor if i wasnt in the military. They save me from the 19% tax. YA 19%.They quoted me for 100 Euro for the gasket and (ABOUT) 600 Euro for Labor. They charge 80 Euro an Hour. So I guess they figured 7 hours and some change. I have already payed up the wazzoo for having a new clutch and Flywheel put it, I would be embarrassed to tell you what I payed for that. I have learned now to buy my parts from back in the states and ship them here. Its kind of like how Porsche would pay up the wazzoo for stuff done to his car in the states. Trust me though its all worth the while when you can go out on the autobahn as fast as you want for as long as you want. I took a ride to a town about 40 mins away I was able to keep it at about 120mph most of the way and occasionally hit 150mph+ I love this place. Keep up the good work. Thanks for your help

 

Also, just before you apply the silicone bead it might help to place the manifold back on and line the bolt holes up to see precisely where to lay the silicone bead. It is easy to get the bead a little off where it needs to be especially on the rear "china" rail.

 

On the LT1/4 you can leave the valve covers in place to do the intake gaskets, so no need to replace those gaskets unless they're leaking

 

Technically you are correct but I mentioned it because if they are leaking along with the intake gaskets it would be a good time to replace them also. I started out to do intake gaskets on my 96 and after getting it apart and got a better look in there I also found a leaking waterpump drive shaft seal, front crankshaft seal, oil pan gasket and oil filter adapter. I ended up stripping the engine down to just a block with heads and I also replaced timing chain set and plastic oil pump drive shaft coupling sleeve in addition to everything else mentioned.