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98 Subi blown head gasket - Anyone surprised?

I got a 98 Subi Forester L, stick, 130k mi. I posted a message awhile back about cooling system problems and with help and advice from some of you, I’ve pretty much determined the car has a blown hg. Even though it wasn’t good news, I still say thanks to those that helped - at least now I know where to start. The problem is, I can’t figure out how to start. She’s a great car and I don’t want to junk her.

I’ve been thinking about what gsragtop & tester mentioned about the silicate stuff and I’m ready to take the chance, but there’s one thing bothering me: If that stuff is supposed to be drawn in to the combustion chamber where the silicate comes in contact with the super hot temps that solidify it, thereby sealing the leak, that assumes coolant is going into the combustion chamber, right? Well, I’ve been driving this car with a blown hg for at least 2yrs maybe 3, (that in itself amazes me), and I’ve never seen any sign of coolant in the exhaust, no smoke, nor any rough starting issues to speak of.

So, my question is simply, HOW THE HECK DOES THAT HAPPEN!! How in the world can I lift the hood and watch exhaust gases bubbling up in the radiator, yet when I park on a hot, 95 degree August day with a fully pressurized cooling system, the next time it’s started there is no sign of coolant. The physics of that defy me! I mean, it says that the head gasket magically blew a “one-way” valve in itself? Huh?? What do you think? Am I missing something? Thanks guys.

A small amount of coolant entering the exhaust stream might not be visible at the exhaust pipe. Are you loosing coolant? If so, how many quarts per 1000 miles?

Don’t know exactly, but very little. Over the summer, I used the car mostly to get to work, round trip was 50 mi and I worked 4 or 5 days a week. Due to excessive coolant coming out to the overflow, I had to constantly pour the overflow back into the radiator to keep it from overheating. Over the summer it rarely needed any extra coolant. The couple times I added, it was small amount, like maybe 1 cup each time.

Does the engine overheat in city traffic, highway use, or both? Some possibilities could be a clogged radiator, inoperative or iffy radiator cooling fans, iffy thermostat, or weak radiator pressure cap.

AutoZone should have a cooling system pressure tester for free use and (knock on wood) they have an adapter for testing the radiator cap. Or you could just replace the cap and see what happens.

We had a Subaru into the shop once with a complaint of coolant loss and repeated testing showed no fault with the cooling system and cap at all. Eventually I determined that what was happening was that at times the engine temps woud spike noticeably higher after the car was shut off. There was a point right around the 5 to 6 minute mark after shutdown that this spike would cause the radiator cap to hiccup and it would cough up about a quart of coolant. Apparenty the cap was borderline (very borderline) weak and that temperature anomaly would cause it to give up for a few seconds.

At this point I wouldn’t blame the head gaskets just yet.

If you had to constantly pour the overflow back into the radiator to keep from overheating, than there’s an excellent chance that it IS a blown headgasket. That empty space in the radiator into which you pour the overflow coolant is probably created by combustion gasses blowing into the water jacket and forcing coolant past the radiator cap and into the overflow tank.

I’m curious. You say you’ve determined that it IS in fact a blown HG. How did you make this determination? What diagnostic steps have you taken at this point?

As a side issue, if you’ve driven for that long with a bad head gasket, there’s a good chance hot exhaust gasses have etched the head and/or block. If you ever decide to replace the head gasket, simply replacing the gasket might not be sufficient.

I have a 1998 Subaru Forester. I was getting white smoke on the highway. The temperature gauge was pegging at the highest hot setting and the coolant was shooting out the overflow tube. I was filling up the radiator every day.

I found a company called Dura Seal (WWW.SEAL-A-HEAD.COM) and decided to take a chance and order the head gasket kit ($149.99 plus shipping) that they sell to seal the head gasket. The formula is custom mixed to each cars engine operating temperature. It does NOT contain glass silicate as glass silicate will not seal a head gasket. It is all explained on the web site.

The directions are simple. It does take about half a day to do the repair correctly. If you can drain the radiator by removing the bottom radiator hose of the radiator and refill it you have the ability to do the job.

It has been two months and the car runs perfectly. Temperature gauge at correct setting, no coolant loss and no white amoke. It was the best investment I ever made. The money the Subaru dealer whould have got is in my pocket and not theirs.

Elwood

Millhunk- if you like, and I can answer any other questions you may have, please post here.

Elwood

I won’t rule out a blown HG. But, I had same symptoms in an '03 Civic and it was not a head gasket problem. I had a small leak in the cooling system, in fact just a loose clamp.

The hot motor would put coolant into the overflow tank. Then when the car cooled the change in temp would allow air to enter the system, breaking the sealed system the overflow coolant was not sucked back into the radiator and motor. I did the same transfer process you are doing a few times and then took the car my mechanic.

The pressure test when the motor was hot showed no problem. Next morning pressure tested again and it showed the leak when the motor was cold. This was about 4 months ago and the overflow bottle is working again as designed. Problem solved.

looked at “seal a head” website and it isn’t clear what they use/and if it is a gimmic. anyone have insight?

Agreed gdawgs. That site is loaded with flashy and sexy graphics with lots of claims (which usually sets off suspicions). It’s difficult to find out how it really works.
Have any others had any experience with it?

It would seem to me that considering a weak pressure cap is a good first step. If you suspect a head gasket try this; and this is by no means 100% definitive but can provide a somewhat reliable indication.
After the car has been sitting all night and is stone cold loosen the radiator cap to release any pressure that might exist.
Start the engine and allow it to run for 20 seconds or so.
Quickly loosen the radiator cap. If you hear a hiss then there might be a head gasket fault. If no hiss, then not likely at all.

I also looked at that site that appears to be spam and it comes across just like many others that promote snake oil fixes.
Any site with testimonials and lots of glitz generally means the vendor is trying to dazzle someone with BS…

Not surprised.

“Bar’s Leak” worked for my wife. NO more coolant loss in several months. Subi Outback 2001.

Disclaimer: I am a HUGE skeptic of any snake oil additive, (and all things bullshit, in general) but I personally know two people who have used this HG sealer stuff, and it actually worked. One guy’s Ford was hiccupping with a blown HG, and after the Bar’s, it purred like a kitten.

To answer ok & mountainbike, the blown HG determination was a bit arbitrary. It’s based on all the symptoms I’ve listed here, plus I can always see air bubbles coming up in the coolant when the car is running & after awhile the coolant gets a bit funky, sort of oily, and smells of gas.
I

Elwood, the dura-seal looks interesting. A bit pricey, but I will consider it. It’s true that all of the other brands use the same ingredient - sodium silicate.

Millihunk, adding the bubbble stream to all the other symptoms, I’d say your diagnosis is definitive.

Considering the vehicle’s age, you might want to try an additive. Your driing it the way it is for the last two years suggests that you just want to squeeze all the life out of it that you can for a few a dollars as possible, and that’s what sdditives are good for.

MILLHUNK DURA-SEAL MAY COST MORE THAN THE HEAD SEALERS IN THE AUTO PARTS STORES BUT IT WORKED FOR ME. IF YOU HAVE A PRESSURE TEST ON THE COOLING SYSTEM DONE (TEST SHOWED NO LEAKS) AND THE MECHANICS VERDICT SAYS IT IS A HEAD GASKET AS IN MY CASE- I FIGURED I HAD VERY LITTLE TO LOSE ($150.00) BUT IT WORKED. I SAVED A LOT OF MONEY THAT THE MECHANICS WOULD HAVE CHARGED AND A LOT MORE IF A SUBARU DEALER HAD DONE THE WORK. GIVE IT A TRY.

ELWOOD

BMW- I’ve heard the same, the only thing is I’ve also heard of it not working, plus I’ve heard horror stories about radiators, heater cores, etc. Mountainbike- you hit the nail on the head. The car’s old and I’m trying to squeeze it, otherwise I wouldn’t even consider the alleged “quick-fixes”.

The problem just got worse. Driving home Christmas night about 5 miles from home (after about 1hr of driving), the temp started rising. By the time I got home it was pegged on H and blowin steam like a old locomotive…merry Christmas. I can’t complain though, she’s hung in there through my abuse of the last couple years. Anyway, it’s blowin steam out of the back of the engine drivers side. It looks like it’s coming from the HG (from between head & block). Maybe it’s finally time to try some “magic goo”?

Try the Goo. And let us know how it works. Who knows, you might even squeeze another year out of the ol’ girl.