Head Gasket Sealers: Opinions? (Page 1/2)
Cliff Pennock MAR 07, 05:20 AM
I think I might have a gasket leak. But only because the mechanic who inspected the car last time around said so. He's actually the only Fiero mechanic I know and he's been working on Fieros for at least 25 years. There are no obvious signs my car has a gasket leak. No white smoke and no milky oil. It leaks coolant but I can't be sure it's leaking coolant in the head since it was also leaking coolant at the radiator (which I replace), the heater core (which I replaced) and now near the thermostat housing (which I hopefully will be able to fix once the weather clears up). I haven't been able to do a test at the overflow bottle because simply put, no coolant ever overflows into the bottle (probably due to the leaks so pressure never gets high enough for the radiator cap to open). What I do notice, is that the car has lost quite some performance the past few years, so that might be indicative for a head gasket leak. Also, due to the failing radiator, and heater core, the engine overheated quite a bit a few times now (well over 270*F).

I asked the mechanic how much the repair would be for a leaking head gasket and he said €2,500 ($2,750) at a minimum but probably much more. I don't have that kind of money and I'm not sure the car (or the engine for that matter) is even worth it.

Yesterday I stumbled upon this YouTube video. The guy tested a head gasket sealer on an old Jaguar with a gasket leak. It was his father's daily driver and it drove perfect for two years until it overheated again and a small leak had returned. They scrapped the car (they wanted to do that anyway) but if I remember correctly, his conclusion was that if he just redid the procedure, the car would be fine again.

If I'm being honest, I much prefer a $35 solution over a $2,500+ solution. Especially since I have no clue how long this engine will last anyway.

Soooo... What are your opinions? Is this something worth a try?
hyperv6 MAR 07, 06:22 AM
Sadly these kind of fixes seldom work or last. You can try it but it is just a band aid at best.

The other issue is they can also plug up the heater core or radiator too depending on the product.

If the car has over heated you may have other issues too like a warped head.

If it is only leaking at the intake that is a good repair for a non mechanic. It is not difficult. Heads can be more involved due to the exhaust manifold bolts.

You can try the seller but I would not rely on it.
Craig71188 MAR 07, 07:13 AM
As was mentioned, most "chemical fixes" are just band-aids to buy some time. Having said that, GM sold a cooling system "conditioner" for the Northstar engines when they had coolant seepage in the heads. Basically, it was Bar's Leaks dry tablets:
https://barsleaks.com/produ...p-leak-tablets-1177/
I have used these in our race car as "insurance" against small cracks/damage to the aluminum radiator and have never seen any clogging. Not sure they ever solved a problem, but GM seemed to think it was a help with the early Northstars that were pulling threads around the head bolts.

I would be careful about some of the more "aggressive" sealants and clogging MAY be an issue.
Cliff Pennock MAR 07, 07:46 AM
I've looked into how most of these work and I'm not too concerned about clogging (the guy in the video above explains it very well in fact, and also why clogging isn't a concern). Most of them need to get in touch with very high temperatures (up to 1000*F) before they loose their liquid form and form a cloth. Those conditions are only met where the sealant comes in contact with the hot gases coming from the cylinder - i.e. the leak.
sleek fiero MAR 07, 10:25 AM
Cliff I would borrow a cooling system pressure tester And pressure the system up to the rating on your rad cap .should be 13 or 15 lbs pressure. try with the engine cold and the engine warm. the system should hold pressure indefinitely. If not look for external leak which it sounds like you have. External leak should be relatively easy to repair. If it is an internal leak your oil would get milky or would leak into 1 or more cylinders. After having the tester pressurized for a few minutes pull the spark plugs and crank the engine over a couple of times to see if coolant blows out one or more cylinders. If it does your head gasket is shot and needs repair Pouring goop into cooling system is a poor bandaid and would probably leave you stranded somewhere possibly doing permanant damage. sleek
Dukesterpro MAR 07, 11:17 AM
Got to be real with you cliff.

If you don't have milky oil, and you don't have white smoke and you don't have a compression leak. You probably don't have a head gasket leak. Why your mechanic would bring that up, even relative to your overheating problems is beyond me. Especially knowing your car has all kinds of external leaks that would cause depressurization and overheating. My thought process is that you are at your wits end with this car, might as well not worry about it, just keep fixing external leaks and see what she does.

I bought a 88GT with magic head gasket sealer crap in it. All it did was clog the heater core, eat up the plastic water pump and transformed a kind of runnable engine into a boat anchor.

[This message has been edited by Dukesterpro (edited 03-07-2024).]

Vintage-Nut MAR 07, 12:13 PM

quote
Cliff Pennock:
I think I might have a gasket leak. / There are no obvious signs my car has a gasket leak.



101 - Identify and Determine the Problem - Don't 'Guess'

As hyperv6, Craig71188 and sleek fiero said and I'll encourage you too - "Don't Do It!"

To me, I will never try "chemical fixes" or "band-aids" as I'm a mechanic and repair my vehicles 'properly'. Given that; I have a garage, tools, skills and the time to do it correctly.

My advice is to put the effort to 'know' IF you HAVE a head gasket problem or not.....

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Original Owner of a Silver '88 GT
Under 'Production Refurbishment' @ 136k Miles

David Hambleton MAR 07, 01:40 PM
My '84 SE (with 300,000 km on the GM warranty replacement motor from 1987) was losing coolant; no noticeable white smoke or coolant in the oil but eventually had a starting issue as outlined in this thread:

https://www.fiero.nl/forum/Forum2/HTML/146435.html

In retrospect, it appears that #1 cylinder spark plug deposits were a clue. You may wish to check your plugs to see if a similar condition presents itself...
richard in nc MAR 07, 05:58 PM
i tried several on my 3.0 ford engine.none worked.but it was pretty far gone by then.
Frenchrafe MAR 08, 05:54 AM
I think mine was probably a crack in the intake side of things (head intake runner or lower intake manifold).
The "quick fix" did work because I have not had a repeat of the problem.

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"Turbo Slug" - '87 Fiero GT. 3800 turbo. - The fastest Fiero in France! @turboslugfiero
https://youtu.be/hUzOAeyWLfM