Overheating

[S Webster]

Hi folks, new to the board, been several years over at the USMB. I recently acquired a 93 Legacy Turbo sedan, to add to our Suby collection, 94 thou. miles, in great condition. It has set for years, but runs strong. I can drive it around for quite some time, & temp stays dead ctr. on the gauge, then for no apperant reason it will suddenly peg it. I've replaced the t-stat & water pump, the radiator flows great, fans both running. It appears there's no flow across the radiator, pass. side upper hose & tank hot, dr. side tank & lower hose cold. I thot' maybe a head gskt., but comp. test shows 130 across the board, & it'll hold that indefenitly. No visable leaks, exh. drips, steam, etc. I'm runnin' out of ideas. Any thoughts, questions? Thanks, S.

[92wagon]

The first question for you is did you replace the thermostat with one from Subaru instead of one from AUTOZONE/NAPA.... etc? Apparently Subies are very picky about them.

[Legacy777]

Welcome to the BBS.

I will second the question about the thermostat and whether you used a genuine Subaru one or an aftermarket one.

[S Webster]

Hi. & thanks Guys. New genuine Suby, 160 Deg. with the tickler pointed up. I've burped it several times, the filler tank is up high by the intake man, which should help in purging air. A friend who has a Suby shop in Santa Fe, thinks it could still be a head gskt. or warped head, & it may take the higher temps to open it up. I only checked the compr. with eng. cold. Still open to all ideas, before I resort to pullin, motor. Thanks again folks, S.

[Legacy777]

Hmmm.....yeah it could be a headgasket...

[wtdash]

Hi,

Does the temp gauge come up to just under 1/2 w/in a few minutes? - you didn't post your locale so don't know if you're in the frigid north or not.

Does the CEL come on when it pegs the temp gauge? I'm thinking the CTS or gauge sensors could be bad?? I believe the CEL is 'sposed to light up when the temp gauge gets too high.

You stated "the radiator flows great" and then "It appears there's no flow across the radiator"...I'm confused.

Does the heater work OK?

No offense, but I've seen lots of people think they burped their rads and they didn't. Since the turbos lack a radiator cap it's bigger PITA than the NA's.

2 things that always work for me:
1. Get the front higher than the rear.
2. Fill the coolant in the engine via the upper rad hose.

I may be confusing my EJ engines, but is there any oil residue in the overflow tank? I know on the infamous EJ25D's they liked to fill the tank w/something out of a science experiment.

GL,
Td

[S Webster]

I'll have to do some checkin' before I can respond well Td. But check this out guys. I ran across an old thread over at USMB on 2.2 overheating. The fellow with the heating problem stated that he had even run a heater core bypass loop to make sure that wasn't adding to the troubles. A guy from England, IIRC, felt that was a good test, 'cause the constantly flowing heater circuit is what heats the T-stat to open. Lookin' at the pump design, that seems plausable. One reason I got this car affordably was a bad heater core (which looks like it's gonna' be a chore). One of the guys at my friends shop installed a loop of hose as a bypass, and I had noticed it is folded flat, (didn't think it would matter). Could I be that lucky? I'm crossin' my fingers and my legs. Know what I'll be doin tomorrow. Keep you posted. Thanks Guys, S.

[wtdash]

Hmmm...I'm thinking I'd get rid of that kink....I'm not sure how the coolant flows but that can't be helping.

And the heater core is right up there w/root canal, from what i've read.....but if you don't need heat???

Td

[S Webster]

Hi. guys, Well the problem is solved. If you stop flow thru the heater core, the T-stat won't open. I'm still not sure why, since both lines terminate in the T-stat bowl, but it certainly is true. I sweated up a 1/2" copper U & hooked it up at the eng. htr. outlets, & the radiator warmed up rite away, & the gauge never strays from ctr. line. Wish all my automotive problems were so easily overcome. Now I have to repl. the htr. core. Any pointers, tips or short cuts? Thanks for all your input folks, S.

[Legacy777]

Unfortunately the dash has to be removed. It's not a fun or easy task, but is the only way.

[silver03]

flushing out your current heater core not a viable option?...or already been done and I missed it?

[S Webster]

No help, core is leaking. Gonna' have to bite the proverbial bullet & tear the dash out. I ran across a thread some place recently, I think it was General Disorder - said he managed to replace the core with out dumping the AC charge. I really hate to open up a good working AC system. Thanks Guys, S.