Blown Head Gasket Sealer Question (not a bike)

[Conman]

I picked up a used ‘95 Miata with 130k miles a few months ago.

Lately, the coolants been bubbling from startup to shutdown and when I run it hard it bubbles violently enough to overflow out of the overflow tank. Zero other issues. Runs fine and temp gage reads normal.

I bought a block tester and the liquid went from blue to yellow indicating there are combustion gasses in my coolant.... looks like a blown head gasket.

Since the car was only a couple grand I’m going to give a gasket sealer a shot before I put a major investment into pulling the head.

My questions are:

A) Being that combustion gasses are leaking into the coolant, rather than simply dumping the sealer into the rad cap as everyone’s instructions seem to say, wouldn’t it make more sense to also pull a spark plug on the cylinder(s) in question so that the sealant is forced into the leak? Otherwise I would think combustion gas bubbles will push the sealant out and keep it away from where it needs to go? Thoughts?

B) Anyone have proven good luck with a head gasket sealer brand? Looking at Bars Leaks at the moment.

 

[gentsvmax]

Assuming the head or block isn't cracked this should will be an easy head gasket job, don't wast your time with the "miracle cure" .

 

[sdt354]

Assuming the head or block isn't cracked this should will be an easy head gasket job, don't wast your time with the "miracle cure" .

I've got to agree. These types of products also clog up cooling systems, oil coolers etc. They don't work long term, if at all. The head should come off and be sent out to be checked for cracks and wrapage. The deck inspected. Cracks are usually between the valves and difficult to see when the head is cool. A torque wrench and good instructional, and you'll be fine.

 

[Fire-medic]

While I agree with doing the remove/repair opinions, I've used the sealers before with good results. It was a 300ZX. I don't think I'd want to do a transcontinental trip like that, but for a 'daily-driver,' it's a way to get-by, many times.

 

[rebeltaz83]

Your asking for allot more trouble if you go pouring that down the cylinder. You'll be doing a full rebuild after that stuff works it's way around the rings. Head gasket is a cheaper way to go.

 

[Fire-medic]

Your asking for allot more trouble if you go pouring that down the cylinder. You'll be doing a full rebuild after that stuff works it's way around the rings. Head gasket is a cheaper way to go.

I'm pretty-sure that the OP didn't mean to pour into the cyl head through the spark plug hole, the sealant. I think his thought was that without the pressure generated by the sealed cyl with the spark plug NOT in-place, the sealant would more-easily work its way into any crevice/crack, when added to the water jacket, as the instructions direct for its use.

 

[Conman]

I'm pretty-sure that the OP didn't mean to pour into the cyl head through the spark plug hole, the sealant. I think his thought was that without the pressure generated by the sealed cyl with the spark plug NOT in-place, the sealant would more-easily work its way into any crevice/crack, when added to the water jacket, as the instructions direct for its use.

Exactly.

 

[Conman]

I've got to agree.

I get it that these have a “snake oil” rep, but even if I pull the head myself, the head still has to go to a local machine shop. With gaskets and other “while I’m in there” parts, it’s looking like >$500 if I pull the head myself. I don’t think that’s gonna happen on a car at this price point. For that cost a used engine low-mileage becomes more enticing.

 

[Conman]

While I agree with doing the remove/repair opinions, I've used the sealers before with good results. It was a 300ZX. I don't think I'd want to do a transcontinental trip like that, but for a 'daily-driver,' it's a way to get-by, many times.

Got a favorite brand? I’m in the same boat where this is a cheap, around town car.

 

[rebeltaz83]

I'm pretty-sure that the OP didn't mean to pour into the cyl head through the spark plug hole, the sealant. I think his thought was that without the pressure generated by the sealed cyl with the spark plug NOT in-place, the sealant would more-easily work its way into any crevice/crack, when added to the water jacket, as the instructions direct for its use.

How is he gonna run the engine? It's suppose to run long enough to reach operating temp to circulate the sealant....I suppose I did misunderstand what he meant lol, my bad.
I see what he's saying.... Me personally I'd just do the head gasket. That sealant will plug the cores in the radiator, water pump. T stat. Anyplace it can build up and set. I used bars leak head gasket stop leak on a car I traded in. Most likely if it's blowing exhaust gasses into the coolant it won't ever seal. Your talking 110-120 psi pushing on that sealant. And it won't ever work if you don't run the engine.

 

[CaptainKyle]

If I was going to use one I would use blue devil . It is a lot more expensive than bars leak etc but one of the best as far as I am concerned

 

[gentsvmax]

Your asking for allot more trouble if you go pouring that down the cylinder. You'll be doing a full rebuild after that stuff works it's way around the rings. Head gasket is a cheaper way to go.

Serious? Down the cylinder??LOL Yer jokin right, makin a funny,LOL,LMAO!

 

[rebeltaz83]

Serious? Down the cylinder??LOL Yer jokin right, makin a funny,LOL,LMAO!

20 years in the auto business, I've seen some.... Questionable things. People filling engines to the valve covers with oil. Roll backing their cars to the shop because it quit running, out of gas. I wouldn't put anything past some people. Using armor piercing bullets to get a wheel off because they needed the tire.

 

[one2dmax]

Actually. I have used Steel Seal before with good results and think I might still have a bottle or two around here. I have not tried it in the Vmax just other cars as a last ditch effort for repair since the labor and parts would have been more then the car was worth.
https://steelseal.com/

 

[Conman]

Really appreciate the responses guys. Looks like I’ll read up on blue devil vs steel seal.

Going to add it to coolant per instructions, but I’ll run the engine with the plug removed from the cyl in question so that sealant is forced into the leak, to clear up my intentions. With exhaust gasses getting into the coolant as my only symptom I don’t see how I can get sealing results unless the cylinder isn’t making compression.

 

[gentsvmax]

Really appreciate the responses guys. Looks like I’ll read up on blue devil vs steel seal.

Going to add it to coolant per instructions, but I’ll run the engine with the plug removed from the cyl in question so that sealant is forced into the leak, to clear up my intentions. With exhaust gasses getting into the coolant as my only symptom I don’t see how I can get sealing results unless the cylinder isn’t making compression.

CONMAN....Conman LMAO