Overheating, what makes a Subaru a Subaru! But hopefully it's just the radiator cap

[Warstud]

Not sure why your assuming it's a Head Gasket. I'd buy a new t-stat and hose.

 

[GSCJR]

@schwinney They're flat braided straps; Hyundai uses something similar. I just made my own with some scrap wiring. Not knowing how long they we're broken, I figured any ground strap is better than nothing. They're visible from under the vehicle at the front lower edge of each cylinder head.

ACDelco EGS8 Professional Engine Ground Strap, Air Conditioning - Amazon Canada

ACDelco EGS8 Professional Engine Ground Strap in Air Conditioning.

www.amazon.ca

 

[Slow Car Sport Mode]

1998 SUBARU LEGACY - Engine 2.5L VIN 6, 6th Dig | USA Parts Online

1998 SUBARU LEGACY - Engine Assembly 2.5L VIN 6, 6th Digit, 60 Months Warranty. Free Shipping, 1 Month Return Policy. Used (Original Equipment Manufacturer). Engine Run, Tested and covered under 5 Years Warranty. All of our Engines are Shipped as Complete Assemblies from Top Valve Cover to...

www.usapartsonline.com

 

[slacktide_bitog]

Not sure why your assuming it's a Head Gasket. I'd buy a new t-stat and hose.

It's a Subaru. They're known for head gaskets

 

[Slow Car Sport Mode]

It's a Subaru. They're known for head gaskets

EJs, yes; EZs (the 6s. 3.0,) no.

If and when your issue develops. The Turbo gaskets are the fix. Installed properly. https://www.amazon.com/gp/aw/d/B01ED8AZYU?psc=1&ref=ppx_pop_mob_b_asin_title

As stated in the thread, Trav prefers the Six Star gaskets and that is fine too.

 

[MRC01]

shopping for head gasket sealers now
ChrisFix did a nice video on the Bar's Leak with carbon fiber

I'm considering that one as well as the cheaper K-Seal sealer mentioned in the video

Be careful with coolant additives, the cure is sometimes worse than the disease. Google Subaru Coolant Conditioner.

 

[slacktide_bitog]

I got the Bar's Leak head gasket sealer with the carbon fiber. After following the instructions, the engine still won't warm up even after an hour! The thermostat doesn't open even at 180-190F!

The heat does get hot, though! The instructions say to turn the heat on full blast, which I did. The thermostat was working when the head gasket blew, as I saw and heard the fans running yesterday!

EDIT: I was finally able to get the fans to turn on.

 

[Slow Car Sport Mode]

I got the Bar's Leak head gasket sealer with the carbon fiber. After following the instructions, the engine still won't warm up even after an hour! The thermostat doesn't open even at 180-190F!

The heat does get hot, though! The instructions say to turn the heat on full blast, which I did. The thermostat was working when the head gasket blew, as I saw and heard the fans running yesterday!

The engine still won't warm up

The heat does get hot, though

Now I'm a little confused.

 

[slacktide_bitog]

Now I'm a little confused.

EDIT: I ran it some more and was able to get the fans to turn on.

 

[Warstud]

If the engine isn't heating up how do you have heat ? Either buy a new t-stat or test the old one. Do you have a way to test the temperature gauge ?

 

[CarLuver]

i once went to look at a 2001 outback. guy said it ran perfect . when i got there i looked into the coolant tank and could be it boiling. guy said that normal for subaru. LOL . yeah normal for one with a blown HG

 

[SubLGT]

 

[nthach]

If I ever did head gaskets on a Subaru, I’m automatically using Fel-Pro’s PermaTorquePlus Laserweld or the EJ25 turbo ones. No coolant conditioner, it’s a band-aid fix for what is an engineering mistake. Sure, GM and Ford were dropping in Bar’s Leak tabs from the factory but still.

 

[slacktide_bitog]

If I ever did head gaskets on a Subaru, I’m automatically using Fel-Pro’s PermaTorquePlus Laserweld or the EJ25 turbo ones. No coolant conditioner, it’s a band-aid fix for what is an engineering mistake. Sure, GM and Ford were dropping in Bar’s Leak tabs from the factory but still.

Agreed. If I decide to replace the head gaskets on this car, I'm definitely using Fel-Pro

 

[Oro_O]

Before selecting any replacement gasket, study this informative post about the Subaru headgasket issues:

https://allwheeldriveauto.com/subaru-head-gasket-problems-explained/

Also, don't underrate what is said about the battery issues wrt contributing to this issue. It has never been solved. I inspected a 2017 Subaru already far down the path of this deterioration.

 

[slacktide_bitog]

I found this thing underneath the alternator that is wet and not near anything that would leak on it. What is it?

 

[Coolant Kid]

Oil pressure switch. I'm very familiar with Subaru and it's something that happens after many years. Be sure to replace it with an OEM part, don't use the cheap aftermarket replacements available in parts store, while they do fit, they don't hold up to the high oil pressure Subys have and will start leaking again after a few months. Put the OEM one in there and you won't need to bother with it ever again.

 

[Trav]

I found this thing underneath the alternator that is wet and not near anything that would leak on it. What is it?

View attachment 86230

Yep oil pressure switch, pop the alternator which is an 15 min easy job and you can get as it easily. The new OE switch will have thread sealer pre applied do not use rtv or teflon tape in the oil galley circuit.

 

[Trav]

If I ever did head gaskets on a Subaru, I’m automatically using Fel-Pro’s PermaTorquePlus Laserweld or the EJ25 turbo ones. No coolant conditioner, it’s a band-aid fix for what is an engineering mistake. Sure, GM and Ford were dropping in Bar’s Leak tabs from the factory but still.

You are braver than I. I am not a against Fel-Pro I do use their gaskets on many things but not head gaskets, its not that I have not used them a few times but they failed or they just were not the correct thickness and dropped the compression and with it power.
I used them on an old Buick 430 high compression engine that used a .025" steel shim gasket and the Fel-Pro was coated and 4x thicker, it turned a spirited engine into a real hound, I replaced them with OE steel gaskets. I was young and still learning, today I would not have use the thicker gasket.

That was my first bad experience with them there have been others that were graphite coated that failed early. I would think twice about putting one on a old B&S lawnmower engine.

 

[Number_35]

I have a bad feeling about this one, this could get real expensive real quick. If it overheated there is a good chance a rod knock could be right around the corner if it isn't already.
The cases may need to be decked as well as the heads planed. then comes the question while it is all apart what other work should be done eg valve job, guides, rings, bearings, line bore the cases, etc.

There is no half stepping when repairing this engine even properly cleaning the case decks and planing the heads using a MLS gasket may not be enough to prevent premature failure of the new HG.
When they overheat the cases expand too much around the crank which allows the crank to get tight, it also twist the cases causing to main bearing bores to go out of alignment.

The cost of machine work is very high today, when I do these for other people I use a brand new Subaru OE short block and have the heads done with 6 stars MLS viton coated HG, absolutly no copper coat.

Another cause for HG failure is broken ground straps from the heads to the frame, I replace them with 1.5" braided plated copper straps as well as adding addition grounds.

Trav, I'm intrigued - please explain why poor grounding can cause HG failure. Electrolysis leading to deterioration of the metallic elements in the gasket or the sealing surface of the head? Thanks.