Torre

I have the common problem of the leaking intake manifold gasket on my '94.
My question is if I simply replace the gasket, is that enough? Is it likely that the manifold is warped?

Also, it appears as though I am passing water into my combustion chamber (water comming out the exhaust). Can this be caused by the intake manifold gasket? I sure hope that its not the head gasket.

Any ideas?
Thanks,
Mark

FSTRNU

If you pull your oil cap and/or your valve covers and find white foam. You have a water leak.

GlockLT4

Yup.. :(

Torre

No signs of water in the oil. None on the dipstick and none (that I can see) under the valve cover. I know for a fact that a head gasket can be blown without ever sending water into the oil passages. There just has to be a breach between the water jackets and the cylinder and you'll burn water.

I guess my question is more of looking for past experiences with Corvette owners.

Has anyone with a leaky intake manifold gasket been successful by just replacing the gasket (i.e. no warpage)? And does anyone have experience with water leaking into the intake valve through a leaking intake manifold gasket?

Thanks again,

Mark

Torre

I just read somewhere that the LT1 intake does not have a water cross-over. If this is true, surely the heads still have the water jacket hole up against the intake right? I am trying to see how likely it is that the water is entering into the actual intake valve at No. 7 through a blown intake manifold gasket and NOT the head gasket.
I may be in denial here :)

Mark

flubuyu2

I have the same thing on a '93 and I like your idea about the hole around #7.when I shut her down after she's hot getting the drip from -off the bell housing.thought head gasket too but no white in oil cap or stick looks very dirty around back of intake as well.runs like a raped ape ....so any ideas you come up with please share....I'll do the same

KLLRVET

The intake on all LT1/LT4's is dry. The heads have no water passages intended to pass through an intake manifold.
Tony

Torre

Yes, mine is very wet at the bell housing also.
I just noticed something else though. When I let the car get hot (at idle) the water starts to drip out of the tailpipes but I also get steam coming from the back of the engine. When I rev it up, the steam comes out faster.

Bummer, I just bought the car and have not even driven it yet (it was delivered to me). I guess I deserve to be screwed since it was idiodic on my part, but I had a family emergency and I could not go get the car. I hope the punk who sold it to me gets his some day :mad

flubuyu2

I went out to check I do have some moisture coming from the pipes as well.I did see in the manual that when ever you flush the coolant you must also add sealer(gm part #3634621)I have flushed the system and am going to try these.maybe the former owner did this too!yes...yes I'd be smokin mad as well!

vettedan

Do a block test, which will tell you if you’re getting any exhaust/oil in your coolant. Are you sure the water you’re seeing is coolant? This time of year is notorious for condensation in your exhaust system, especially if your not driving far enough to heat the exhaust to burn it off. An internal combustion engine exhaust will produce water from the nitrogen in the air. LT1 do not have water jackets in the manifold.
Dan

Torre

Dan, thats a beautiful ride you've got!!!
I hope you are right about the condensation. I'd feel pretty stupid though.
Here is the latest. I forgot to mention that the car has been driven a total of 5 miles since I bought it 3 weeks ago. I let it sit in the driveway at idle until the temp got to 220. And water started coming out of the tail pipes. Well, I jumped in it today and drove it down the interstate at about 80 mph to the next exit, filled her up with premium and came back. Total run of about 15 miles. I got-on-it a couple of times too. It sure feels healthy. So when I got back to my driveway, I let it idle until the temp got to about 230. This whole time I reved the motor and watched for the water drip and steam from the tail pipes. There was none!!!
Oh, could it be that simple? I sure hope so. I plan on flushing the radiator as the existing coolant looks spent.

I will also try to get this exhaust in the coolant tester kit too.

As for the wetness on the bell housing and the steam (it is actually burning oil. I do have a decent oil leak back there that I need to get fixed.

Mark

Aggravated4life

My Corvette Steams alot when warming up,especially on cold days.
ALot of condensation builds upin these xhaust systems and Im not suprised because alot of times, we corvette owners dont drive the car everyday.
ALso, I once bought a used car that ran fine but a few days later it let a cloud of thick white smoke all down the road as i drove along.
I thought the headgasket was gone...but I remembered the car sat for many months outside and I realized I had alot of water in the oil.
I replaced the oil and the smoking stop.
I also think I had some water in the gas tank as well from condesation...filled the car up a few times and it ran better and better.
Just wanted to share that...its not uncommon for these cars to steam alot at times and as long as theres no coolant loss and smell,it should be fine.
:)

AquaMetallic94LT1

Has anybody tried to check the torque on the head bolts. The intake bolts eventually get loose because of thermal cycling of the motor. I wonder if the same thing happens to the heads.

vettedan

The oil you’re seeing on the bell housing is probably coming from the rear of the manifold. Chevrolet had this great idea of using RTV to seal the valley of the manifold. Camaro LT1 has the same problem. My isn't bad yet! When I build an engine I never do the RTV seal. I've been burned on it.
Dan



[Modified by vettedan, 3:58 PM 2/16/2002]

Goody

I had the leaky intake problem on the back side as most have had with the LT1 engine. I pulled the intake and replaced the gaskets, except for the end seals. I didn't use the included rubber parts. I sealed it with good high quality sealant and haven't had a problem since. I did the whole tune-up thing at that time since you have to take so much off the car. PITA!! :smash:

Torre

Thanks Goody,
I read some of your past posts. So, you did not need to do any work to the intake manifold right?
Just new gaskets and it was fixed?

Mark

cire96

Mark:
Take a couple of deep breaths. It's going to be fine. First, an engine with a coolant leak (into the combustion chamber) will almost never emit liquid from the exhaust. If it's "drinking" coolant (with anti freeze in it) it will however smoke like a MI tank smoke screen!
The tailpipe water is almost certainly harmless condensation that a good drive will cure. The Chevy 350 is known to occasionally develop mysterious and very small water leaks at the intersection of the head and manifold. Such leaks are often only observable with the engine warm (but not hot) because they'll expand shut at full operating temperature. If you can find water leaking off the back of the bell housing after it's been running a few minutes and it can't be found after an hour of use, that's likely your problem.
My advise is get a can of GM stop leak and put er in! That's what the dealer will do if you have the intake gaskets replaced. He'll even put it on the bill (in addition to the grand or so for the gasket replacement)! Good luck. Cire96 :)

SPD DMN

Replace the intake gasket, use good Permatex RTV instead of what comes with the replacement gaskets, and button it back up. Let the RTV cure for 12 hours or more and start the car up. The condensation sounds like the normal condensation that all C4's get. It is about a 4 hours job, but not difficult to do if you are somewhat handy with tools.

Torre

Thanks for some of these later responses.
Here is a follow-up. Not a blown head gasket, just a lot of condensation.
I replaced the intake manifold gasket last weekend. I used Permetex Copper at the front and rear. It appears to be a success, No more leaks. The intake was so filthy when I pulled it off that I literally hosed it down.

The entire job with coolant change, oil change, etc. took me 8 hrs.
I read an old post where somebody suggested that it was a 1 hour job for somebody who knows what they are doing. I don't know who the poster was, but I will bet him the title to my car (for his) that not even a NASCAR mechanic can do this job in 1 hour! That is, do it right. Heck, it took me over an hour just to clean and prep. the parts after I got them off!

GlockLT4

yeah, you can't pull an intake, replace seals, put an intake back on and refill fluids in one hour.... :crazy: :crazy: :crazy:


[Modified by Glock'94, 1:01 PM 3/1/2002]