1800cc Over-heating Problem

Hello group,

I have a 1982 Subaru Brat w/ the 1800cc engine. A couple years back I was having an intermittant over-heating problem. Unfortunately, I did manage to overheat the engine to excess one day and ended up popping one of the head gaskets and warping the head. I tore down the engine after that and did a rebuild on it. The rebuild has only about 1,500 miles on it, but I'm again experiencing the exact same over-heating symptom.

Here's what happens... in city driving, over a period of a couple weeks or so, I will lose about 1 qt. of coolant from the radiator. However, in sustained highway driving at speeds of 55-65 mph (3,000-3,500 rpm) the radiator loses over 1 qt. after about 30 minute of driving. I've checked this girl over from stem to stern. The only place that it's losing the coolant is straight out of the overflow on the filler of the radiator itself. There are NO other leaks. I've actually watched the overflow belching coolant out while I was standing there.

I know what you're gonna' say... change the cap! Well, that's been tried 2 or 3 times now. I even spent $18 on a OEM cap from the local Subaru dealer. That didn't help either. She's great for knockin' around town, but I can't trust her on the open road for long trips. This little truck was my mother's at one time. It was her pride and joy. The thing only has 70K miles on it, no rust, no dings or dents, etc. It's a nice little truck. That's why I took the time and the expense to rebuild the engine and keep the thing. I have two other trucks and a motorcycle, so none of them get driven excessively.

Anyone here with some suggestions or ideas, I'm open. I've discussed this with a couple "master" mechanic friends and they're stumped. The last suggestion I received was to have the radiator flushed out, but EVERYTHING was flushed and cleaned just 1,500 miles ago, when I rebuilt the engine. Like I say... any suggestions will definitely be considered by me. Maybe someone else out here has had this same problem in the past.

Either post here or reply via email -- snipped-for-privacy@softhome.net

Regards,

Reply to
V.T. Eric Layton
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Mebbe you've got a few plugged cores in the radiator. Sounds like my 86 GL about 8 years ago, I flushed till blue in the face, and still overheated on hot days with AC running. Was totally stumped, talked to my Scooby's big job mechanic; he asked me when I'd last changed antifreeze, said Hmmmmmm not sure. Suggested I replace the radiator, and bingo. No more overheating. Guess that's what I get for not listening to scheduled maintenance suggestions when it came to cooling system. I do now.

Mark

Reply to
pheasant

Reply to
Tony Hwang

Check for an internal coolant leak where the intake manifold connects to the cylinder head(s), and/or at the head gaskets. Coolant entering the intake passages or combustion chamber here is more or less undetectable unless real severe (you can smell it in the exhaust sometimes, may give plug tips a yellowish tint), but leaks in these areas, especially at the head gasket, can over pressurize the coolant system, causing the radiator cap to barf coolant. If that's all nice -n- tight, I'd get a nice clean junkyard radiator and try that. Oh, I assume you've checked that _both_ fans work, the fan temp switch on the radiator is OK, and the thermostat is opening as promised . . .

ByeBye! S.

Steve Jernigan KG0MB Laboratory Manager Microelectronics Research University of Colorado (719) 262-3101

Reply to
S

Hey Folks,

Thanks for the quick responses. Yep, everything was flushed less than 1,500 miles ago, when I did the rebuild. As to whether the head/gasket are all right, well... there seems to be no eveidence of burning of coolant in the combustion chamber. There's no evidence of burned coolant in the exhaust. I've been advised that a faulty head gasket can create excessive pressure in the radiator, but this is the exact same problem this engine had prior to the rebuild. I'm leaning toward a radiator problem. Amateurish flushing attempts by me previously probably served no purpose. I'm going to end up taking it to a radiator specialist and let them "rod" it out properly and see if that will alleviate the problem. Thanks for the helpful advice all.

Regards,

Reply to
V.T. Eric Layton

Hi,

While rodding out the radiator MAY do the trick, it's very likely you're throwing good money after bad. Before taking it to the shop, why don't you get a hold of the folks at

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Ask what they have for your car, especially if they have a double row core. Their prices are surprisingly good, their service also good (although I'd suggest if it's practical that you pick up your new radiator at a local warehouse so you can match it with the old one right off. It took three different catalog numbers to get the one that fit my car best.)

Many here on the NG have reported poor results with cleaning clogged Subie radiators, which is why I suggest you investigate a brand new one.

Best of luck,

Rick

Reply to
Rick Courtright

Reply to
Edward Hayes

I 150% agree with the Rick's and other's recommendations here to

*replace* the radiator. BTI (Before The Internet - in my life anyway) I learned this the hard way too. I messed around for 2 years convinced that if I cleaned the radiator enough, it ought to clear it out. By the time I figured out that it wasn't getting any better, I had to replace the heads.

My experience and that of countless others says that cleaning/rodding - either DIY or by a shop - does very little if any good on these radiators. The tubes are so small on the inside that the slightest buildup will clog them with no chance of clearing, PLUS the external fins corrode away and/or fill totally with sand and/or bugs so no air can get thru to do its job. Reversing that is impossible (or at least not worth the time that it takes even if you *could* be even marginally successful at it).

Replace the radiator - radiator.com - and have done with it.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

Reply to
Bill Putney

Replace the water pump also. Pump failure is common in your vehicle and will give very similar symptoms to what you are reporting. (Cools better at low speed/rpm) Not to say it is not your radiator but if I were betting a buck on this I would bet on the pump.

Steve

Reply to
SuperPoo

Pump is brand new... less than 1,500 miles. It was replaced when I did the rebuild last Spring. It's relatively easy to replace, but I think I'll try the rad first. ;)

Thanks...

Reply to
V.T. Eric Layton

Went through many overheating problems with my '82 1800 engine a few years ago. Replaced the head gaskets and other stuff. Still didn't fix the problem. Replaced the radiator and that fixed the problem.

Reply to
Ed Fortmiller

Well if the pump has only 1500 miles on it, that blows my theory. Good thing I did not bet the buck.

Steve

Reply to
SuperPoo

Well, you know, Steve... that's why they call it "gambling" and not "winning". ;)

Later...

Reply to
V.T. Eric Layton

Wow, Ed! That makes me much more confident about the radiator change out. Sounds like you went through all the same crap I went through. I couldn't call Radiator.com today... it was a bit of a hectic day. I'm gonna' try to give 'em a holler tomorrow.

Thanks,

~Eric

Reply to
V.T. Eric Layton

I'm not sure how good/bad aftermarket Subaru radiators are as I have never used one of those.

Sometime ago I needed to replace my heater core in my '82 so I bought an aftermarket unit. When I pulled out the original Scooby one it had more fins and more tubes. Put the aftermarket one in and it never functioned as good as the original Scooby one. On cold winter days the interior of the car never got real warm.

Reply to
Ed Fortmiller

Well, I had the choice between OEM and aftermarket when perusing the Radiator.com website. I chose the aftermarket due to its cheaper price and the fact that it had a lifetime warranty. As far as heater cores go... well, here in Tampa I could light a couple matches in the cab of the car and that would heat sufficiently for any kind of Winter weather we get down here... ;)

Later...

~Eric

Reply to
V.T. Eric Layton

Hi,

I'm not sure about other vendors' products, but I went with a two-row core from

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last summer on the advice of several folks from the NG. Recently, my auxilliary fan died, and I haven't had a chance to replace it. But the two-row radiator actually runs cooler with one fan than the factory unit did with both (and barely warmer than it did with two fans.) This is in temps of 100F+ here in SoCal.

HTH,

Rick

Reply to
Rick Courtright

Same here - on my (previously - now sold) '86 turbo wagon, it had one belt driven fan and one electric. I actually was able to leave the belt driven fan off, and the temp gage would stay in the middle on the hottest day of summer with the a.c. going full blast.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

Reply to
Bill Putney

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