1996 legacy outback 2.5 with an interesting problem. She intermitently gets hot. No engine light, no codes showing any bad sensors or circuit malfunctions. New--- water pump, radiator, rad cap, thermostat. There are absolutley no leaks. I can notice some detonation occasionally but the knock sensor is not throwing an error code. Any suggestions?

I have a similar problem, I have traced it to one of my fans. I can get one to come on from heat/air conditioning. The other fan will not come on! I have jumped power to it and it will work but the sensors aparently will not turn it on.

 

I checked my relays by swapping them around and was able to eliminate them as a problem?

 

I ran a thread on this a while ago I think it was "Forester cooling issues"? The board was most helpful.

 

Good luck

Glenn

82 SubaruHummer

01 Forester

1996 legacy outback 2.5 with an interesting problem. She intermitently gets hot. No engine light, no codes showing any bad sensors or circuit malfunctions. New--- water pump, radiator, rad cap, thermostat. There are absolutley no leaks. I can notice some detonation occasionally but the knock sensor is not throwing an error code. Any suggestions?

How many miles?

Hate to be the bearer of bad news, but…..

Sounds like the early stages of the infamous 2.5 Head Gasket failure.

It has 142,000 miles. Loses no water, runs awesome. You think it is going?

How many miles?

Hate to be the bearer of bad news, but…..

Sounds like the early stages of the infamous 2.5 Head Gasket failure.

Nope, fans work great and operate when they are supposed to. I already checked that area.

I have a similar problem, I have traced it to one of my fans. I can get one to come on from heat/air conditioning. The other fan will not come on! I have jumped power to it and it will work but the sensors aparently will not turn it on.

 

I checked my relays by swapping them around and was able to eliminate them as a problem?

 

I ran a thread on this a while ago I think it was "Forester cooling issues"? The board was most helpful.

 

Good luck

Glenn

82 SubaruHummer

01 Forester

It has 142,000 miles. Loses no water, runs awesome. You think it is going?

The 2.5 HG does not leak externally, it leaks internally. They allow exhaust to enter the cooling causing sporadic overheating. Do a search on 2.5 head gaskets and you will get all the info you need on this topic.

I have had much the same problem with my '97 gt 2.5, check, check for an air pocket in the cooling system. I had to totally remove the thermostat and run it without a therm. for a while to finally get the air out. Also, fill the radiator from the upper radiator hose, back fill it until it overflows - that gets rid of alot of air. Finally, beware, it will finally get really really hot and blow water all over, not good for belts, etc.

 

 

 

1996 legacy outback 2.5 with an interesting problem. She intermitently gets hot. No engine light, no codes showing any bad sensors or circuit malfunctions. New--- water pump, radiator, rad cap, thermostat. There are absolutley no leaks. I can notice some detonation occasionally but the knock sensor is not throwing an error code. Any suggestions?

This does sound like a HG problem. You can get a block check done for a small amount of cash and this will tell you if that is the problem.

 

The same kind of thing happened on my '88 GL-10. After the HG's were changed the coolant temperature didn't vary by much, and in all kinds of outside temperatures.