Questions and Answers

Subaru Getting Hot And Bothered

Q. Vincent... I hope you can help. Here is the info re: my car
1985 Subaru DL
Engine size: don't know
Manual 5-speed transmission
Mileage: just over 91,000 (it had 74,000 when I got it 2.5 years ago)
Carburetor

Here's the problem:
I drive 25 miles (one way) to work. The car has been running fine until recently. It was fine driving to work one day, but coming home (weather was hot) it started cutting out and losing power along with over-heating about half-way home. I pulled over and let it cool down and then made it home, but the temp. rose again. It starts and runs fine around town on short trips (I live in a very small town). I put a new air filter on it and noticed that the old filter appeared to have oil in it. Any help you can give me would be most appreciated. I'm hoping it is something that I can fix since car repair prices here are out of my range.

Regards,
Marilee

A. Gee, whenever anyone calls me Vincent, I feel like I'm in trouble. The car definitely sounds like it's overheating Marilee. Since you didn't mention the car has A/C, I'm going to assume it doesn't.

There's a couple of things you can check to see what's causing it. First thing is to check the coolant level. With the engine cold, locate the radiator cap. It should be right on top of the radiator. With the palm of your hand, press down firmly, turn the cap a quarter turn to the left. You'll feel the cap is loose when you move it, but it's still locked on. (This first turn is to release any pressure in the radiator.) Then, pressing down once more, turn the cap another quarter turn to the left and take it off.

NEVER REMOVE THE RADIATOR CAP ON A HOT ENGINE!
SERIOUS INJURY AND BURNS CAN RESULT!

Look inside the radiator and you should see the coolant. It should be up, almost, to the top of the radiator. If it's not, fill it with a 50/50 mixture of anti-freeze and water. If it is up to that level, is it a nice, clear green color? if it looks like something that fills a baby s diaper, the cooling system needs to be power flushed and refilled with fresh coolant. Be sure to fill the coolant reserve tank as well. There is a Full Hot and a Full Cold mark on the side. Fill it accordingly.

While we're at the radiator, look at the front of the radiator. Make sure there is nothing obstructing the air from moving through it. You may want to take a hose and, from the engine side, wash out the fins to clean out any road dust, leaves and dead bugs that may have accumulated. Don't use too high a pressure, high pressure could damage the fins. If necessary, you can take a soft brush and scrub the front of the radiator to get the tough stuff. Scrub in the direction of the fins and not too hard, you don't want to deform the cooling fins.

Assuming the coolant is as it should be and the air flow is not blocked, the next thing to check is the cooling fan. Replace to radiator cap. Match the tabs with the cutouts on the fill spout. Press down firmly on the cap and turn it to the right a quarter turn. Give it a jiggle to be sure it's in place. Though the cap shouldn't be tight at this point, you shouldn't be able to lift it off, either. Turn the cap another quarter turn to the right, still pressing down, until you feel it lock into place. It should be locked tight now and won't move if you try to wiggle it.

Start the car and let it run. Watch the temp gauge (if it has one) and see if the cooling fan comes on. Be sure the heater is turned off and the temperature selector lever is set to cold. When the gauge get's to a little more than halfway, the cooling fan should kick on. If the fan doesn't come on and the engine starts to overheat, turn the engine off and walk away from the car for an hour until it cools down. That fan comes on at a set temperature and if it doesn't that means the cooling fan temp sensor is bad and needs to be replaced. That is not an expensive part nor does it cost much to replace. It is also possible, but not as likely, that the fan motor itself is bad.

These are the two most likely causes of your overheating. If the coolant is low because it boiled out when it overheated because the fan failed to kick on, then that would explain the coolant loss. But if the fan is working and the coolant is low, then you could very well have a leak in the cooling system. That leak would need to be located and repaired to permanently repair the over heating problem.