Overheating Mystery!

[lapalindromist]

I received a '87 Subaru GL from my parents for graduation last summer. It had been the family car, and then became my dad's commuting vehicle (approx. 2 mi. each way). Since roughly 2000, this car has been overheating frequently. My dad didn't keep up with the maintanence, until I got it, he couldn't remember the last oil change or tune up. The problems since I've had it are as follows:

1. Before giving the car over to me, my parents took it into a shop to fix the overheating problem my dad had been experiencing. The radiator and the thermostat were replaced at this time.

Car behaved for approx. one month.

2. After I started college, the car began overheating again, making an oil-related clicking sound. My oil pressure gauge has a ground fault in it, so no help there. After checking the oil, I took it to have the oil changed -- turned out to have over 7 quarts of oil. I asked the man if the oil had any water in it (suspecting a cracked head, etc), and he said no, it was just the dirtiest oil he'd ever seen in a while.

Car behaved for one month again, but with strange engine noises and transmission slipping.

3. Car started overheating YET again. I had noticed that there was constantly no coolant in the tank, and took it into the shop where the water pump was reported to be "leaking like a sieve". Replaced that, fixed collapsing radiator hose.

Car behaved for less than a month, noises louder, transmission pain in the butt.

4. On the advice of an Auto Store man, I got a tuneup. No more noises. No more overheating. Much less transmission slipping.

Behaved less than a week.

5. Took it on hour long trip up mountain. Car behaved remarkably up mountain, pulling 8% and 9% percent grades without a complaint. On the way DOWN, however, the car overheated constantly -- spiking and then going back down. The noises were worse than they've ever been at all.

Got dad to look at engine while hot, found that heater supply/return hoses squirt coolant when you hit gas. Fixed hose.

5 mile fix. Back to overheating after that.

6. Last night, got home with smoke pouring out of the hood, temperature gauge normal. Strange banging noise in addition to the other noises. Sickly sweet smell from car. Absolutely NO heat from the heater.


Any ideas on any way to fix this thing? I'd like to get this whole overheating buisness out of the way so I'll know whether to install a CD player in it, or know whether to just try to find another car.

Oh, the mechanic said at the time of the water pump incident that I do not have a blown/cracked head gasket or a rod problem.

This car has always been weird, but this is mindblowing!

[pod]

i think tou have a buldup in yout engine jacket , or air in there. id take it to a trusted mechanic and have them flush the entire sistem (be careful with this one becouse if you get a bad mechanic all the crap is going to go to the heater core and break it )this seams like the culprit and other than that you could tighten all the hosess and make shure that they dont have air stuck in them

[zee_mikey4u]

okay, i have one of these cars. they are fun, but unique with thier problems. i have had this issue before SEVERAL TIMES. now, your heater core is probably cracked or plugged, have your Ignition timing checked, if the car is improperly timed on the timing belts or distrubiter, then the vehicle will run hot at random. there is a really big chance that this little hose coming from the heater core that appears to go to the manifold to heat the gases coming in has a hole. you have to take off the filter on the carb <if APPLIES}. YOU MUST KEEP YOU FLUID LEVEL FULL ALL THE TIME. keep the plastic resevour full for the radiator. you shouldnt have ANY probs if you have all of these probs looked out. good luck! contact me if you need to, i am buying a second one as my love for these cars.
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[BadAssAuditude]

I agree with zee_mikey4u & pod. Sounds like the heater core, I'd replace it and recheck; especially since yer Dad didn't keep up on the maintenence, it could be quite contaminated/plugged. That sweet smell is, 9x's out of 10, the coolant. And since the heater isn't working...well then....sounds like a good place to start. And check the timing as previously mentioned.
On another note, I have an '82 Brat that I absolutely love and won't get rid of. A few years ago it had some overheating problems due to electrical problems and the weird thing was that when I drove home at night with the headlights on uphill, the engine overheated. Go figure. So I had to drive home 6 miles out in the boonies on a one lane dirt road in the dark and when I absolutely could not see, I drove with just the running lights on. The engine didn't get as hot but still ran a little warm. Unfortunately I don't recall off hand what we did to fix it, sorry. I'll get back to ya on that. Anyway, despite that problem, I love my 'lil Brat. It's had some other problems, too but it's never left me stranded. Maintenence is sooo important, (for any vehicle). I can't stress that enough. And change the oil frequently, yer motor will last a lot longer. Good luck!

[lapalindromist]

Update. I think that it might have been fixed, as the heater hoses were found to have been leaking, and I replaced them -- so far it hasn't overheated again! And the tranny has been fixed, the modulator was leaking. Pretty cheap fix, just 2 hoses and a modulator. HOWEVER, I'm still losing coolant, having to fill it up about every 20 miles I drive. Think the heater core is at the root of this problem?

Also, the timing in the car is horrible. Sometimes it will idle at 3000 RPM, sometimes 900... you can watch the needle jump around. Any ideas what might be causing this? (Most likely the results of some really really bad noises?)

[chevytruckguy187]

this is easy. well, it is now that i have searched over a hundred engines in junk yards and they all had the same problem. on ohc/ohv subarus the heads crack/blister, between the valves, especialy on the right side.
if it over heats, and its a subaru look there first. oh and by the way the heads can be pulled without removing the engine. just make sure to use (spray) copper coat on the head gasket,and center it on the head.some have studs instead of head bolts. remove nuts holding engine mounts to cross member and jack or lift engine up. this will allow enuf room to remove heads. one more thing just how much turbo boost will they handle? depends on how thick the fenders are to catch the heads when they blow off... hehe... oh fun

[chevytruckguy187]

oh i forgot change the timing belts very often. if you hear a knock or idles irradicly or whatever change them its cheaper then bent valves.

[Calebz]

The cracks between the valves are normal.. as long as they arent excessively huge, they won't cause problems..

How much boost?.. stock late 80s turbo soobs are set for 7-8psi

Mine runs 12psi no trouble

as far as changing the T-belts.. they are to be changed every 55k or so.. however, if one breaks, there will be no subsequent damage.. its a non interferance engine.. no valve damage when a belt breaks.

[martinicharlie]

I am 99% certain that you have a blown gasket. This problem has become more apparent with the more powerful Subarus, but the basic engine design (the boxer - horizontally opposed pistons) is the same. I had the same thing with my 89 1.8L DL - blown gasket and the same symptoms that you are describing.

Charlie

[martinicharlie]

I mean head gasket