Overheating Subaru Forester


I have a 2001 Subaru Forester. It overheats (the temperature gauge goes up to red) if I go over about 40 miles per hour. Before I discovered this, I noticed the radiator was empty. (By “empty” I mean it drank about a 1/3 container of coolant.) Unfortunately, a full radiator doesn’t solve the problem; it just allows me to drive a little bit longer before the car begins to overheat. So I refill the radiator every 2 days and drive in the slow lane on the freeway with my hazards on at about 55 mph (hey, I still have to get to work!). Interestingly, sometimes the temp guage goes up, I’ll slow a little (to about 50 mph) and it’ll come down again (to a little above halfway). If I hit traffic (which I never thought would be my saving grace!), the temp guage will invariably come down.

My mechanic kept the car for a couple of days, but he couldn’t find a leak in the radiator. He put in a new thermostat (didn’t charge me), but that didn’t solve the problem, either.

I don’t know what to do. The last Subaru dealership I took it to was a crook. My mechanic seems pretty honest – and he honestly doesn’t have an answer!


Pertinent facts, which are absent: how many miles on your Forester? Have you changed the timing belt and water pump?

We had a somewhat similar problem with our 03 Impreza. The timing belt was inspected, not changed, at the recommended interval, by a non Subaru garage. Not long after we had coolant leaking, and were advised by a mechanic in Fort Stockton, TX, that the water pump “goes in these things at 100,000 miles”.

Might be worth exploring the water pump for your overheating problem.


It has about 73,000 miles, but that sounds like a good suggestion. Many thanks.


OK, I’m no Subaru expert. I’ve owned three or four of them, and never had a problem like yours.

Do the electric cooling fan(s) come on as they should when itr gets hot? That could cause a problem like yours. Is it “drinkng coolant” which never seems to show up on the pavement? If that’s the case, it could have a bad head gasket. As far as the water pump is concerned, it is RARE for one to quit pumping, but it can happen if the impeller wears down, or begins slipping on its shaft. Is the radiator’s AIR circuit plugged with dirt? If so, you may be able to rinse it out back to front with a garden hose and a good nozzle.

That said, if you don’t find a good answer here, try http://www.ultimatesubaru.org/forum/ There are a bunch of guys there who really know their soobs.


You may need a headgasket test performed.

On ANY vehicle driving a vehicle repeatedly to red zone/overheating WILL DESTROY your engine. So your need to “get to work” may have cost you an engine.

Your mechanic may be honest however cooling system problems are pretty simple in the relative scheme of honest repair. Find a new mechanic possibly the dealer for a real diagnosis.


I agree. Continued driving of this car while it was overheating may have led to warped heads and possibly other internal damage.

I would strongly suggest having a different mechanic check the coolant with his emissions “sniffer” to see if byproducts of combustion can be detected in the coolant. If so, then it is almost certain that you have a bad head gasket.

Do not continue to drive this car unless you definitely have a few thousand $$ for the replacement of the engine! Get thee to a competent mechanic immediately.

Sorry for being the bearer of potential bad news.