Jump to content
Ultimate Subaru Message Board
N0TKG

'91 Loyale overheating

Recommended Posts

My Subaru is having overheating issues. The problem first appeared last summer when I would be driving around in town in 100 degree weather but once back on the highway heading home she would cool back down to normal. But the problem gradually became worse. Sometimes the fan would kick in, sometimes not. Offhand I can not remember what I did to check the fan last summer, but I remember that it was not the problem.

 

The past few times I have used it the fan has not ran and the car would overheat if idling too long, but if I ran the heater I could keep the temperature close to normal and then once at highway speed the car was ok. I had decided that I would bypass the fan thremo switch so that the fan would always run and was waiting for a nice day to do that.

 

During all of this I have checked the exhaust for any sign of coolant smell and so far nothing there. I've had head gaskets go on a couple of GLs over the years and it was usually easy to know when that happened.

 

Yesterday I had to make a quick trip to town. This time she ran hot on the highway, and even with the heater going I could barely keep the gauge out of the red so I turned around and headed for home and planed to hot wire the fan.

 

When I got home I noticed that the top radiator hose was hot, the lower hose was barely warm, and the fan was not running. This morning I put the thermostat on the stove and it opened just before boiling, so I figure it is OK.

 

So now I am thinking I probably have a radiator that had been gradually becoming plugged. Does this sound like it could be the problem?

Share this post


Link to post
Share on other sites

Would be a good idea to flush the radiator, and just for good measure put in an OEM thermostat (even if yours is OEM) and probably replace the hoses... you should be okay but if you arent careful, the overheating could blow your HG and warp the heads....

 

Do you have a secondary car you can use by chance?

Share this post


Link to post
Share on other sites

id start with the thermostat. if you just want to test you can pull it out and put it in a pot of boiling water on the stove. if it doesnt open then thats the culprit. if it does open, probably a clog or something preventting the flow.

Share this post


Link to post
Share on other sites

From what you say I think the radiator should be replaced also. They do go bad over time. You might also have the coolant checked for exhaust gases to see if there is a head gasket leak.

Share this post


Link to post
Share on other sites

Yeah, sounds like there is barely any coolant flow near the bottom of your radiator, which is where your thermoswitch is, too. I'm fixin' that if there isn't enough coolant flow, your switch isn't getting hot enough to turn the fan on.

 

You can get a cheap radiator for 45 bucks on ebay. I have one in our Loyale that has been problem free for over a year now. Free shipping on it too.

 

New radiator, new hoses while you're at it. Thermostat wouldn't hurt. Good luck!

Share this post


Link to post
Share on other sites

I am 18 miles from town so I always have at least two running vehicles, usually three or four. LOL

 

I had to drive in to town to buy a new thermostat gasket so I decided to pick up a thermostat while I was in town. If I want OEM I would have to order one, so I just bought what was available.

 

I aimed a flashlight down into the radiator and it is looking rather slimy down there so I am thinking that is the most likely problem. This thing has been coming on gradually over the past six months. I should have a relatively warm day later in the week so I plan to drain the radiator and see what comes out.

 

I have a radiator here that I took out of my old 85 GL. They look the same, but some sources show it as compatible, other not. What do you guys think? If it fits and the engine runs normal I would not see it as a permanent solution. I'd still order a new one. But this old one is here, now.

Share this post


Link to post
Share on other sites

If everything fits to the old one I don't see problem using it. The engines are basically the same thing.

Share this post


Link to post
Share on other sites

It's too windy to work on anything outside but I started the car and drove around pasture for about ten minutes until the temp gauge was near the red. The upper hose was hot and the radiator felt warm across the top. Down by the thermo switch it felt slightly warm and the lower radiator was cooler than my skin and cold at the lower hose output area. It sure does seem like a plugged radiator.

 

I found a new radiator on Ebay for $60 so decided to buy it instead of messing around with the old one out of the '85.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×