'91 L has a temp fluctuation issue....

[silence2-38554]

Hey everyone, we just picked up a '91 Legacy L FWD Sedan for my girlfriend for 500 bucks. It was cheap due to having 234k miles on the clock but all in all seems to be in alright shape! The main thing we're concerned with is a potential overheating issue. After warming up, the temp. needle will gradually climb up toward the dreaded "H" but then start to gradually descend right before it goes into the red. At first I thought it was maybe a head gasket but there is no oil in the overflow and the exhaust isn't spitting out any visible smoke at all indicating burning coolant. It was previously owned by a mechanic who claims to have recently replaced the thermostat, but the symptoms seem to me like:

-The thermostat is, in fact, faulty & needs to be replaced.
-There is air in the system (possibly being caused by a HG but hopefully not)
-Something goofy is going on with the water pump.

I read another thread on here where a couple members were having a similar issue & it turned out to be one of the lines going to the heater core was kinked. I will check this out tomorrow & report back. Any ideas would be greatly appreciated. Thanks!

[speedmaxx]

If the thermostat wasent replaced with a oem unite this could be causing the over heating. I had a duralst thermostat In legacy for about a year then. Started haveing the same issue your having, replaced it with a factory one and all is well

[silence2-38554]

I hear 'ya. In my old Integra, I had two NAPA thermostats fail in one week. The Legacy has a NAPA oil filter on it now, so I wouldn't be shocked if the failing thermostat is from there, too. I'll order an OEM unit asap. thanks!

[silence2-38554]

So.... I further investigated the cooling system as it stands this morning. The overflow was totally empty. The radiator took about a gallon of water before topping off. Thing is, it never really stopped producing bubbles after filling. I let it idle a good 5 minutes & there were just constant small bubbles coming up. This has me worried that it may in fact be a HG with air from one of the combustion chambers getting into the coolant. I haven't had time to drive the car around & see if topping off the coolant solved/helped with the temp fluctuation issue but I will asap. thoughts?

[Legacy777]

I would highly recommend checking the thermostat. If it is not a subaru thermostat, you will have problems.

Here are some pictures of the stock thermostat
http://www.main.experiencetherave.com/s ... P_4799.JPG
http://www.main.experiencetherave.com/s ... P_4801.JPG
http://www.main.experiencetherave.com/s ... P_4804.JPG

Also, there is a bleeder screw on the passenger side of the radiator that needs to be open while you fill the radiator. Start the engine with that bleeder screw off and then keep filling until coolant starts to bubble out, then fill the rest of the way from filler opening.

If you still have issues, then you may indeed have a headgasket issue.

[silence2-38554]

Okay, today was a big day for the car. It got an oil change, new front diff fluid, new Subaru thermostat & new coolant. Thing is.... when I got the thermostat housing off, I found that the previous owner had "modified" the thermo by clipping the entire spring assembly off.... It was just an open plate. So, I went ahead & installed the new thermo, new lower radiator hose & filled with coolant. Drove for about 2 miles & all of a sudden the needle shot from operating temp up into the red. I pulled over & coolant was erupting out of the overflow. Damn it. Blow HG. I also did a compression test & came up with these numbers:
#1-140
#2-142
#3-172
#4-130

Thing is, all the cylinders seemed to hold pressure pretty steady. Am I right to suspect #4 due to it's having the lowest number? Honestly though, we picked this car up for 500 bucks & really only need it to run for about 2 years of light use. Is it worth tackling the HG or should I just throw the open thermo back in & drive it as-is? Can anything else be damaged by doing this? It's obviously not the correct thing to do but if it'll run for that long I think it might have to work....

[Legacy777]

What you described sounds a little odd for a head gasket. When you got it back to your house, did you refill the coolant and see if the car would start/run? With the radiator cap off, can you see bubbles come up?

[silence2-38554]

What else do you think we might be looking at? Water pump? I thought the overflow erupting coolant was pretty indicative of HG's? Also, I should note that the coolant in the overflow REALLY starts to smell like exhaust gas after a while, which almost certainly means head gasket/s. At this point we really just need to know if & what other damage leaving the free-flowing thermostat plate in will cause....

[Legacy777]

The free flowing thermostat is like running no thermostat. I would think that you will just see temps lower than what they should be.

[tturnpaw]

thermostat. i know this because ive had this issue this week on a friends subie. OEM is the only way to go. BTW this was a month old duralast.

second, did you bleed the coolant? leave the cap off when cold, start it till it gets warm, top off when needed.

how old is your rad cap?

still have issues, headgasket or cracked hose.

[acworld34]

I have basically the same problem. I took out the thermostat and was running it like that but then.

The radiator is drinking the water / coolant i put into it. If it is the head gasket what shoulkd i do?

I also bought the car from an auction and i don't think it is worth putting a lot of money into it.

[Legacy777]

If it is the head gasket, you can try and replace the head gasket, or try and find a used motor to swap in.

[acworld34]

If it is the head gasket, you can try and replace the head gasket, or try and find a used motor to swap in.

If it is the head gasket how long do you think the car will last?

[silence2-38554]

Yup, I bled the coolant by means of the bleeder screw on the passenger side of the radiator. As I said, the coolant in the overflow smells STRONGLY of exhaust. Only way this could happen is that exhaust gasses are exiting the combustion chamber through a coolant channel due to a blown head gasket. If anyone has any other ideas explaining why the coolant would wreak of exhaust, please tell me. At this point, we're strongly considering just throwing the open plate back in & run the motor 'till it just totally gives up & something catastrophic happens. Not my first choice, but it's my girlfriend's car & her budget. The other option would be to look for some known-level, non-cracked EJ22 heads & swap them in when doing the HG's. That way we wouldn't have to waste the time & money having the current heads decked & checked for cracks. I'm gonna try filling & burping the system one more time with the thermostat in place but if overheating & overflow canister erupting ensues, the open plate's going back in for now unfortunately....

[silence2-38554]

Also, other than reduced fuel efficiency & having to top off coolant every once in a while, what would be the downside to just continuing to run it with an open thermo/lower operating temps?

[silence2-38554]

Okay, new symptom: I just went out & tried re-filling/burping the system with the thermostat in one more time. After letting the car idle for about 15 minutes, I tried backing the radiator's bleeder screw off just a bit. Lots & lots of thick white foam and gas pressure came out & didn't stop.... but when I re-plugged that & went to carefully loosen the radiator cap, cold coolant came out.... The top hose is getting quite hot, while the bottom hose is staying stone cold. Is the thick white foam enough to diagnose this as a HG & call it a day?

[tturnpaw]

sounds like its possible you have a clogged radiator, or could still be a head gasket issue.. you can always have it flushed. and ive bought two legacys one for $300 and a turbo for $600. both still run perfect with a little work. These cars are worth a bit of money so i suggest you spend it instead of on another vehicle that is much worse as far as cost and longevity.

BTW never have seen any EJ series engine with cracked heads. The EA series yes, very many. The EJ22 did come with garbage head gaskets from the factory.

[Legacy777]

If it is the head gasket how long do you think the car will last?

No telling. Depends how bad the leak is and if it gets worse.