Could sure use some help from someone more knowledgeable than I: Car in question is a 1989 Mercury Tracer, but these have a Mazda 323 engine. It overheated, and I'm pretty sure the head gasket blew. (Milkshake oil, water drip from exhaust, etc.) I decided to try liquid glass on the head gasket - specifically, "Bar's Leaks Head Gasket Repair" - but I'm still having problems.

I should mention the steps I've taken so far (some of which were just for maintenance):
- Replaced the thermostat.
- Back-flushed the cooling system.
- Flushed the heater core separately.
- Replaced the radiator cap.
- (And as I said, added liquid glass.)

What's different now:
The good:
- It starts and runs better.
- There's no more sign of coolant in the oil, nor oil in the coolant.
The bad:
- Smoke is still sputtering out of the front of the engine in some spots, which I take to be unsealed cracks at the head gasket.
- The heater isn't producing hot air.
- The coolant overflow reservoir still bubbles (presumably from exhaust gas.)

I'm wondering now if the water pump is bad, and that maybe the liquid glass can't fully circulate to where it can seal the cracks. The radiator hoses stiffen up when the engine is running, which I would have thought meant that there's pressure and that the coolant is being pumped through the system. Except that the top radiator hose gets warm/hot while the bottom hose never really does… I'd rather not replace anything else without knowing that I've nailed down the cause though. Any suggestions?

Thanks much in advance.

 

Bubbles in the resevoir means compression is leaking by the head gasket and entering the cooling system. Using liquid glass will not fix it but will cause more problems. It coats everything it comes in contact with so your heater core could be screwed. Blown head gaskets create steam. Steam rises to the top of the engine where the thermostat is. Thermostats need to be submerged in coolant to work properly so steam will cause it to stick. Basicly you need to pull the cylinder head and check it for warpage( it is probably warped) a machine shope will rebuild it for 100 bucks or so. You are stressing the cooling system by running it with a blown head gasket. It is not a very big job on those. I can have a head off one of those in an hour. Reasembly and cleanup is about 4 hours.

 

Head gasket sealers can and do work. I realize it's not necessarily a long-term solution, but I want to try the crack sealer to find out where I stand. Because if there's more wrong with this engine than just the head gasket, then it's going to the scrap yard.

Although that does raise a question: how can I tell if there's a bigger problem beyond the head gasket? I'm no car expert, and I've never had a serious engine problem before, but I would think it would run horribly, if at all, and it isn't doing that.

Anyway, I'm thinking I need to verify water pump function to know that the head gasket sealer is circulating to the cracks. The radiator hoses stiffen when the car's running, but does that really mean anything? If it does, then why doesn't the bottom radiator hose get warm? What kinds of tests can I try here?

 

Sealers are a bandaid used mostly by used car lots to get rid of a car. Use of sealers can cause more damage in the long run which is what you are trying to avoid. Water leaking into a cylinder causes cylinder wall and ring damage if not repaired quickly. Most likely you have a warped cylinder head by now. Sealers are not meant to fix blown head gaskets,there is too much compression working against it to correct a head gasket leak. A sealer can fix a very very small leak/seepage but never a head gasket.

 

Ignore the questions, selectively read the post, argue about sealers. Gotchya.

I don't have all of the links in front of me at the moment, but for anyone who's interested in reading about debate on sealers, reports of their use, etc, here's one page: http://wiki.answers.com/Q/Do_%27head...rmaGasket_work

This is a junker hatchback, and the sealer will be fine for now. Moving right along.

 

I addressed your question of damage to the engine. I worked for Mazda 20 years and have done over 100 head gaskets on those. The only way to know what damage has occurred is to pull the head. I have turned wrenchs over 30 years now and can say with absolute certainty sealers do not work on head gaskets. You can link all the advertising hype you like. I know first hand from doing,not reading about it.

 

Okay, so the only way to know if subsequent damage has occurred beyond a blown head gasket is to pull the head? What if the sealer worked, but the head had already warped - there's no symptom for that?

The link I posted is for the curiosity of others who might read this thread, not as a counter-argument to you - that's actually stated pretty clearly in my previous post. If they read it, they'll find it's not sponsored by any advertisers, contains first-hand accounts of the use of sealers, as well as responses for and against their use from a variety of sources.

I don't dispute your knowledge or experience, but there's knowledgeable mechanics out there who have used sealers with success. You're disagreeing with them, not me. I have, as yet, no opinion on sealers whatsoever. But since you say you have direct experience with them: When's the last time you tried one? What product was it?

 

In order for compression to get into the cooling system it must first get by a compressed steel ring around the cylinder. To say that a liquid poured into the cooling system can take the place of a compressed steel ring is rediculous. A warped head has the same symtom as a blown head gasket,it really depends on how badly it is warped.

 

Not so compelling: "I don't see how a liquid can harden to approximate the properties of steel. I don't understand how it works, therefore it doesn't."
Better would be: "My expert understanding of the chemistry of these formulations leads me to believe they are/aren't viable."

Your personal experience with them is irrelevant - you don't have a large enough sample size to go on, and you don't know if they were used properly in that handful (probably less) of cases.

You've already stated your recommendation for the head. You want to debate sealers? Get your own thread. As it is, you're high-jacking mine.

 

I'm actually trying to help you not damage your engine further by throwing garbage into it that will not help but only further the damage being done,but you don't seem to have enough common sense for it to sink in. So go ahead and destroy it.