After the road trip, BIG coolant leak

[vetteboy86]

I have noticed coolant on top of the intake manifold a few times. Each time I dried it all up with a rag, and it never came back. Well the trip down all was well, car ran great. The next day, I got it out in stop and go traffic, and the car got way hotter then usual. My bro was thinking water pump, but when we opened the hood, my greatest fear became a reality. There was puddles of coolant in almost every hole on the passenger side of the intake manifold. It was burning it off as well. Well in a trip that was 760 miles, I used about 3/4 of a gallon of antifreeze. I dried it all up, started the car and no leaks, took it for a short drive and no leaks.

I have been informed that it is probably my intake manifold gasket leaking. Well, I am going to look for a leak the next few days. I have checked the oil regularly, and there is no problem there.

I am not opposed to pulling the intake gasket, and putting a new one in, and putting everything back together. I will probably do it myself, but need info from the guys who have done it. What are the problems, and what are the special things to do. I have a factory repair manual, does anyone have page numbers that helped.

Lastly I have heard nightmares about people doing this and it leaking still. I only want to do this once. What usually goes wrong. Is there a wrong type of gasket or permatex to use.

If I pull the manifold, is there one I can put on to increase performance. For now the engine internals will remain stock. In the future I do plan on making a few more ponies with the motor. Is there an intake manifold that will achieve the best of both worlds, working on a stock motor, and a slightly modified motor?

Thanks,
Craig

 

[cash's90]

There are many posts discussing intake manifold gasket replacement. You should also hear many more suggestions in response to your post. My suggestions are; 1) Make note of every step of the disassembly with particular attention to vacuum hose runs and connections. 2) Clean all gasket surfaces thoroughly. 3) Don't skimp on the silicone sealant (Permatex Black, The Right Stuff, etc. that you use for the "china wall" seals at the front and rear of your manifold). 4) I applied Permatex "Hi Tack" gasket maker to both sides of the new gasket water passages. 5) I replaced the Torx type manifold bolts with grade 8 flange head bolts after one of the original Torx bolt heads stripped during the torquing sequence. The factory manual is a good guide. Good luck.

 

[tigmaned]

check the heater hose that runs into the throttle body on the right side, mine was all drie rotted, and the way the enigne seats any leak up there would send the coolant back onto the intake. also check the thermostat house mine was leaking there too and also sent coolant to the left side of the intake. i changed both and no more coolant seating on the intake.

 

[SPANISHVETTS]

check the heater hose that runs into the throttle body on the right side, .

Yelp you need to pinpoint the leak before you rip her apart. Buy, beg, borrow or steal a cooling system pressure tester and gently take the pressure up until you find the leak.
I had the intake leak last year. It is no big deal – just a bunch of time taking the manifold off and putting it back on. Be sure to use enough of the RightStuff.
If your intake is not ported now is the perfect time to do it. What else are you ever going to use that Dremal that you got for Christmas ´01* for?:eyerole You might as well burn up the bits cleaning up the intake and make the Vette breath better. *Any man who has not received the dreaded Dremal for Christmas or Father’s Day has not been married long enough.:W

 

[Moonunit 451]

Ever see this :confused http://www.corvetteactioncenter.com/forums/showthread.php?t=67617 or this?
http://www.corvetteactioncenter.com/forums/showthread.php?t=69485
They aren't that old

 

[vetteboy86]

Sorry if I have overlooked any threads lately. I haven't read as much as I should, and I was so upset I just made a new thread. I will read up on what I need.

I did try to pin point the leak, and now I cant find one. I cleaned the engine really good. Dried the best I could, especially where the coolant was last seen. Started the car up, and let it idle for a good while, well past operating temp. I even took it for a ride, and no leak. I checked the thermostat housing, and the coolant lines.

What exactly does this pressure tester do? Can I buy it at autozone?

 

[tomtom72]

The cooling system preasure tester looks like a pump with a hose attached to a radiator cap. The test is you take off your cap and put the tester in it's place and pump up some preasure...slowly to what ever your system is rated for. Then you look for any leaks. I would expect any good auto parts store would have it, maybe even Sears. I'm not sure about this but I think there is a dye you can use in the coolant sys. to trace a leak. I could be wrong about that, it might be wishful thinking on my part. It's been a long time between me turn'in wrenches.


Good luck, Tom

 

[I_R_DA_ONE]

The cooling system preasure tester looks like a pump with a hose attached to a radiator cap. The test is you take off your cap and put the tester in it's place and pump up some preasure...slowly to what ever your system is rated for. Then you look for any leaks. I would expect any good auto parts store would have it, maybe even Sears. I'm not sure about this but I think there is a dye you can use in the coolant sys. to trace a leak. I could be wrong about that, it might be wishful thinking on my part. It's been a long time between me turn'in wrenches.


Good luck, Tom

When you do this test ,,,attach the tester to the radiator , then bring the engine up to running temp. and leave it running while you do the test....the different metals expand at differant rates and this could be the cause of your leak.... Put sealent around your bolts when you replace them....also check for a leak in the radiator on the passengers side that may be spraying back on the motor.....Mike R

 

[RedZR]

I went through this with my old 91 L98. The dealer did a repair twice (failed both times) and I did it the last time (fixed it for good). I utilized some advice that Hib had provided and as usual his advice was spot on.


First, use FelPro gaskets and a GOOD rtv sealant on the front and rears of the block. Make darn sure everything is very clean.

Next, use High Tack gasket sealer (spay can from NAPA worked) on the arears around the water jackets.

Finally- use Lock-Tite on the intake bolts- not the teflon sealer the dealership uses. Also, let the car sit overnight befre adding any fluids after you assemble it, the RTV needs time to set

It worked for me

 

[Toms007]

Man Craig, so sorry to hear of your problems, I can't offer any advice just glad to hear you are making headway with the fix. It was good to see you at BG. Good luck with the fix.

 

[vetteboy86]

From what everyone is saying "the right stuff works" what other kind of sealant is out there. I just figured all the rtv stuff was created equal.

 

[SPANISHVETTS]

From what everyone is saying "the right stuff works" what other kind of sealant is out there. I just figured all the rtv stuff was created equal.

To sum it up in a single word; NO. Use TRS the first time and be done with it.

 

[Don Rich]

Coolant leaks

There are many posts discussing intake manifold gasket replacement. You should also hear many more suggestions in response to your post. My suggestions are; 1) Make note of every step of the disassembly with particular attention to vacuum hose runs and connections. 2) Clean all gasket surfaces thoroughly. 3) Don't skimp on the silicone sealant (Permatex Black, The Right Stuff, etc. that you use for the "china wall" seals at the front and rear of your manifold). 4) I applied Permatex "Hi Tack" gasket maker to both sides of the new gasket water passages. 5) I replaced the Torx type manifold bolts with grade 8 flange head bolts after one of the original Torx bolt heads stripped during the torquing sequence. The factory manual is a good guide. Good luck.

Take several digital photos of the engines manifold and load them into your computer. You will have an accurate record of all the vacumn hoses, wires,clips etc.

I took several pictures of my 1966 Chevy Chevelles brakes before I took them apart. Spring, clips, shoes etc. It was invaluable when I went to reassemble the brakes.

 

[Vettefan87]

Luckily his brother has an 87, so he will be able to use that as a hands on guide to be able to put it back together, since I know he will forget how to .