Question: Head Gasket repair in a bottle? Do any really work?

[chris123]

On my 1986 Convertible that I just purchased used, it seems like it may be using a little coolant. I have used the Bar's Head Gasket Repair/Stop Leak in the past, but don't really want to gunk up the cooling system, etc. on something that really won't do much good anyway. Has anyone had any positive experiences with any of the products out there on the market? I thought I saw one thread that someone posted that they has some success, but can't remember what brand it was. I'm hoping that if it is a small enough breach, maybe one of the higher end quality products may do just enough to seal whatever portion may have developed the small leak, and save me some $$$ on a head gasket(s) repair.........
Thanks

 

[Hib Halverson]

On my 1986 Convertible that I just purchased used, it seems like it may be using a little coolant. I have used the Bar's Head Gasket Repair/Stop Leak in the past, but don't really want to gunk up the cooling system, etc. on something that really won't do much good anyway. Has anyone had any positive experiences with any of the products out there on the market? I thought I saw one thread that someone posted that they has some success, but can't remember what brand it was. I'm hoping that if it is a small enough breach, maybe one of the higher end quality products may do just enough to seal whatever portion may have developed the small leak, and save me some $$$ on a head gasket(s) repair.........
Thanks

Bars Leak will "gunk up" your cooling system. That's how the stuff works.

It coats the entire inside of the cooling jacket with a pliable substance that is said to flow or weep into and plug small leaks. The problem with that is, the coating also interfers with the cooling process by slowing the transfer of heat from the engine's hot metal parts to the coolant. Even if Bars Leak can fix a leak from the cooling system into the engine, if it's a leak into a cylinder, Bars Leak will not seal the other way, ie: it won't seal compression that leaks out.

If the engine is using coolant, the first step is to see where it's going...one of three places: 1) to the atmosphere via a leak to outside the system, 2) to the atmosphere via head gasket leak from the cooling system to the combustion chambers or to the oil via a head gasket leak into the oiling system.

If you determine the problem is a bad head gasket, fix the engine. Also, your car has aluminum heads and coolant leaks from head gaskets can also eventually damage cylinder heads.

 

[John Robinson]

As Hib said there are only so many places it could go. A bad radiator cap is one. A leaking water pump. A small hole in a hose. A leaking heater core or radiator. Is the overflow tank empty? The first thing you should do is get a pressure check of the system including the cap. Look carefully for signs of a stain on or around any connections that would indicate a small leak. Unless there is obvious evidence of water in the oil don't do anything to the heads. You are a long way from that decision.

 

[chris123]

Hib/John - Thanks for the replies, that's what I figured, I just had hoped that the technology had improved over the past 20 years or so beyond just dumping sludge into the radiator and hoping for the best............

So far, no visible leaks on the ground, but will pressure test to be sure; haven't had the car long enough to make an exact determination, so I will continue to investigate further; it blows a little smoke during the first few minutes of warm-up, then it goes away; my concern was when I was working on the A/C system last weekend, the fan came on at 223F as normal, however the coolant was bubbling/boiling back into the overflow tank; not sure I've seen that before; it has a new AC Delco 195F thermostat and all new hoses; the bubbling stopped when the temp went back down to around 200F; I just purchased one of the low fan temp switches from Corvette Central to turn the fan(s) on at 200F and off at 185F; also ordered a new AC Delco radiator cap (RC-27), so we'll see how that goes; need to drive it and put some additional miles on it to see if it is really losing any siginificant amount of coolant; just changed the oil, and it still looks great, so I'm hoping it's nothing major; just curious, how much should a shop charge (both parts and labor) to replace both head gaskets on these L98's?

 

[FForward]

I had a similar problem, coolant loss and no visible signs of leaks. Also had a little white smoke out the back. I found my problem to be caused by an intake manifold leak. The wiring that runs on top of the valve covers along the intake block seeing down there good. I noticed a small puddle of coolant way down there. I replaced the intake gasket and problem solved. I have heard that this is a common problem with intakes leaking. Good luck, hope its something simple.....Bill

 

[chris123]

I had a similar problem, coolant loss and no visible signs of leaks. Also had a little white smoke out the back. I found my problem to be caused by an intake manifold leak. The wiring that runs on top of the valve covers along the intake block seeing down there good. I noticed a small puddle of coolant way down there. I replaced the intake gasket and problem solved. I have heard that this is a common problem with intakes leaking. Good luck, hope its something simple.....Bill

Bill: Thanks; so far, I can't see or smell any coolant anywhere on the intake manifold, however I will keep that in mind, and keep a close watch on it since I have heard that has been a common problem in the past as well..........

 

[Hib Halverson]

Bill: Thanks; so far, I can't see or smell any coolant anywhere on the intake manifold, however I will keep that in mind, and keep a close watch on it since I have heard that has been a common problem in the past as well..........

An intake manifold gasket leak may be internal, ie: from the water cross over into the intake port. If that's the case, you won't see it.