78Vette-SA

(Note: I had an earlier post about discovering a leak and trying to track it down. Well, I have and thanks for the help folks!).

The engine runs great (93 Chevy LT1 w/ Aluminum Heads) but there is a very tiny amount of water seeping out from the head gasket on both sides near the rear. It's barely enough to drip after about an hour of running the engine, but I can see it start to build up a little.

I replaced all the top-end gaskets with new Fel-Pro gaskets. Everything else seems fine.

I figure I have two choices to get rid of it.

1. Pull the headers and valve covers and re-torque the heads. I did it to spec (Haynes Manual) and in the increments and order the book stated. Perhaps my torque wrench is not calibrated correctly.

2. Or should I go the distance and pull the heads and replace the gaskets? I really really hate to do this.

I guess I could try #1 first and see if it solves the problem. But wanted some suggestions and wondered if I should just go the whole way.

The leak is right near the casting numbers in the pic below, right below the #8 cylinder. It's definately water.

bandy123

Like you said. Do 1 and if it doesnt help all you can do is try 2. i wish that was all i had to do to my 82. i have to rebuild the motor.

scottw

I agree, Try #1 first and if it doesn't help you have to go to #2.

zwede

It's been a while since I took the heads off my LT1 (96 Z28), but I remember steam lines bolting the rear of the heads. Do you have these? If you do, they may be leaking and not the head gasket.

Shutdown1

..... I don't know, but if you can't get it fixed how about selling me that engine for $500? Regards


'74 Turbocharged 350 "Molested to Perfection," class of '71

clem zahrobsky

try BARRS LEAK sealer,GM does on all new engines out the door. :chevy

jbroughton

Seems I remember seeing on the Buick GN list that GM sells a tablet that you can put into your cooling system that seals minor leaks like this. I believe some of they guys over there had used them with some success.

Just make sure you're not leaking into the oil - antifreeze will take out your bearings in short order!!

Jeff

clem zahrobsky

that pill is BARRS LEAK in tablet form that can be found at most auto parts.

yellow 72

Mr. zahrobsky is absolutly right, I've seen pro engine builders drop em in the block and then install the freeze plugs.
I use some type of cooling system sealer in every new motor I use :yesnod:

Paul 75 L82

Motor looks great. That re-tear down will never be as easy to do as now.

Tom454

Well guys, I'm going to stray from the pack on this one... and here's why- no flame intended... so don''t get upset with me...

Reason #1-
I just finished a rebuild of a Ford 5.0. The engine had seized due to over-heating. When I tore the block down, I found a huge mass of "stop-leak" built up between the two rear cylinders on one side of the block... and this is where the piston had seized. I had to chisel it out. The rest of the bores were fine. The owner had been dumping "stop-leak" in to solve a leaky heater core problem.

Reason #2-
I repair radiators- I unsolder the end tanks and sandblast the tube frames... "stop-leak" looks at the ends of the tubes as a "hole" and tries to plug them. The build up around the ends of the tubes contributes to over-heating problems.

I admit I have used "stop-leak" in the past... over 25 years ago, but ever since I saw the damage it can do, I avoid it like the plague.

I also build engines (professionally) and I never resort to using "stop leak" as a preventative measure. If the block is prepped properly, it is not needed. The way I prep blocks, there is no chance for a leak... and I never had a problem.

Just another one cents.

MIKER

Joe, I believe that this is the "GM" tablets that Jeff is referring to.
The package says it is a vegetable formula that contains:
Ginger
Almond Shell
Turmeric - CAS 458-37-7
Sal soda



Since it is a VERY slow leak, it may cure itself but I don't think it would hurt to use this stuff. Much easier than your option #1 or #2.



[Modified by MIKER, 8:16 AM 1/6/2002]

78Vette-SA

Thanks to all for the suggestions. I guess I'll start the job and see how easy it goes. If it seems like the heads may not be tight enough (I'll borrow a calibrated torque wrench!) then I may just pull the heads and replace the gaskets and re-torque. I hate to do it but I'm gett ready in the next couple of months to send the car to the body shop for body work and paint. I don't want to deal with this after the work is done.

Thanks again!!!

Shutdown1

...Tom454,


Glad you stayed from the pack on this one and I am glad you don't recommend using the Barr's Stop Leak (especially with an engine like his!). Other than taking the heads back off, I would just hope he tries getting the engine warm and retorqueing the bolts. ....But I have a question for you regarding the Barr's Stop Leak: What if you put it in your cooling system hoping it would stop a small leak or seapage, -then drained all the coolant and put new antifreeze back in? You might stop the leak, and eliminate the build-up problem that Barrs (or similar products) can cause. IN your opinion could Barrs be used in this manner? Not so much as looking for a quick and easy fix, but what a deliema trying to decide whether to tear down a perfectly good motor over minor water leakage! And let's face it, Barrs does work as advertised and there aren't many products like that on the market anymore. I would like to hear what you have to say on this. Regards

'74 Turbocharged 350, "Molested to Perfection," class of '71

clem zahrobsky

those pellets are BARRS LEAK and they only solidify when exposed to air and if you use the proper amount it will never plug up a cooling system :chevy

Shutdown1

Re-posting.....

Tom454

Okay- I'll elaborate- based on my own professional experience.. not literature... not manufacturers claims... and not others opinions...


The products do "work as advertised" for stopping leaks. No disagreement there.
However, based on the work that I do, and seeing the plugged up radiators, heater cores, and engine blocks, I have genuine, warranted doubts about the claims that the product ONLY plugs leaks, and nothing else. I don't believe everything I read... including marketing hype. I base my opinions on what I experience in "real life". My experience shows that use of additives to stop leaks is a risky business, regardless of whose product you use... including Barrs. It is supposed to only solidify when exposed to air... but this is not a 100% truth based on what I have witnessed.

I'm not the worlds greatest radiator repairman, so I make mistakes. After I sandblast and repair the inner portion and resolder the end tanks, I sometimes find that I accidentally heated up one of the tubes (which are not seamless) and after the radiator is re-installed, the tube leaks. These tubes are extremely difficult to re-solder. As soon as you heat up the leaky spot, the tube comes apart further on down the line. So you end up chasing a leak. So I dump in some Barrs Leak. Then I find out that I missed a tube end, so I have to unsolder the tank again. And guess what? The Barrs Leak has started to accumulate around the tube openings. I don't know how or why... and I don't care. I just know that over the years I have developed a solid mis-trust of advertisers claims and my solution is to simply avoid these products... if there is a mechanical failure, causing a leak, I address the problem at its root source and do the repair correctly. This is why I never get "callbacks" that are my own fault.

I don't like tearing down an engine right after I build it either... but if something is not up to par, I jump in and do the job right. It's that extra little measure of motivation that separates winning engines from losing engines, and it USED to separate the USA from other countries. I remember when the first Japanes cars started showing up in the USA... total piles of junk... laughable. Then we taught them about quality control, and now we are playing catch-up. But I digress...

Regarding replacing the coolant immediately after the leaks stops... well... pay yer money, take yer chances.

I'm not saying these procucts do not work. I'm just saying based on the work that I do, and seeing the radiators, heater cores, and engine blocks from the inside rather than just being an outside observer, I have my doubts and I believe they are justified. So I just don't use the products.

Last year, I did a heater core in a Ford Crown Vic- This job (for this particular year) requires you to drop the entire dash out of the car, drop the steering column, and remove the stamped steel dash framing. It is a horrendous job. Hoses, wires, connectors, etc etc. Major, major surgery. If you think a Vette is hard to work on, try one of these. It's a humbling experience. One year later, I had to do it all over again because the new heater core (made in Mexico, bought at CarQuest) was leaking. The leak was caused by a missing crossbar that bridges the two tubes where they go through the firewall. When the hoses are installed, the tubes flex, and the solder joint at the core breaks. So... I could have used "stop leak", but I didn't. I re-did the job using the correctly manufactured part... purchased from Ford. Since the leak was at a stress point, it probably would have re-occured anyways. Now... if this was your car, and you had me do the heater core, which way would you prefer me to fix it? Pour in the "stop-leak" and let you deal with the problem when it breaks again? Sweep the dirt under the carpet, or pick it up with a dust pan?

This is why I don't use "stop leak". Based on my experience, in the long run, it is better to address the problem directly.

If you bought a brand new C5 and paid $50K for it, and the heater core leaked coolant all over the carpet, would you drop in a can of "stop-leak"? Would you return the car to the dealer and demand they add some "stop-leak"? Or, would you demand a new heater core? Why?

I admit that some of this is border-line philosophy, but there just ain't no way that anyone can convince me that "stop-leak" is a "good" thing. Based on the messes I have repaired, it Just ain't gonna happen.

Shutdown1

Tom,


Thanks for your further elaboration and opinion on stop-leak products. I asked for your input because of you experience and open-mindedness which I have witnessed several times on the forum.
You've convinced me to just let some of my water seepage wait till I have the time and mindset to go after the root of the problem (gawd, this engine runs so sweet, I don't want to touch a single bolt!). But no stop-leak for me, not even putting it in, and washing it out.
It's nice to know that there are still people out there who do the job right or not at all -and on their customers cars as well. Nice meeting you on the forum. Kind regards,

'74 Turbocharged 350 "Molested to Perfection," class of '71