First off, whosever idea this was, bravo and thanks. I have had problems with overheating intermitently for the past couple years(~167,000), but after several days, maybe a coolant flush, it would stop. Finally, after moving to the Northern VA area, the car would not stop overheating. But it wouldn't start overheating until after 7-8 minutes of driving. I took it to a new mechanic, and he said the radiator was clogged, and changed the radiator and thermostat. Still overheating. He then changed the water pump, which he showed me the old one had the fan tongs melted down(I guess due to coolant not passing through while still running). I took the car out the next day, and about 8-9 minutes in, the gauge started to slowly move upwards, but only when I would come to a stop for more than a minute. If I start off quickly(get the engine around 2500 rpm), then the gauge goes back down, but then when I come to another stop, it will slowly start moving up again. I took it back, the mechanic said drive it a couple more days. Could it be an air leak? Can I check myself?

Are you sure the radiator fan is working? When idling, turn on AC and make sure radiator fan turns on. Good luck.

Yes, both fans are running well.

Hi,

 

Going by the fact that running at high RPM keeps the temperature in the normal range, I would guess that there is a clog in the system somewhere, such that a high water pump RPM is needed to get sufficient flow.

 

Try using a cooling system cleaner, one that will go through and remove buildup. Make sure that it's approved for aluminum engines, though. When doing a coolant flush, do you also open the block drains?

 

Good luck,

Adnan

Hi,

 

Going by the fact that running at high RPM keeps the temperature in the normal range, I would guess that there is a clog in the system somewhere, such that a high water pump RPM is needed to get sufficient flow.

 

Try using a cooling system cleaner, one that will go through and remove buildup. Make sure that it's approved for aluminum engines, though. When doing a coolant flush, do you also open the block drains?

 

Good luck,

Adnan

I agree, you might also try to burp the system to get all the air out.

Thanks for all the advice. The service guys did the flush, so I hope they did it right. I went back and found some more information in some previous threads about OEM Subaru Thermostats. I'm going to burp the system, and if it continues, call the service center and ask if they put in a Subaru Thermostat, it seems like that could be keeping the coolant from flowing properly.

These are real finicky about air in the system.

 

 

The genuine subaru thermostat has a 'jiggler' on it which will allow air to escape, while the aftermarket ones do not.

Update on the Legacy: I took it on about a 70 mile round trip today, on the way out, at a stop light, the temp gauge started to slowly creep up, but when I pulled away, it went back to normal, and didn't move again for the rest of the trip. On the way back, it stayed steady the whole way. It shouldn't have moved on the way there, so I'm not convinced the problem is solved, but it's some good news.

I had a problem like that with my Dodge minivan but I found this stuff at the parts store that dropped the temp by 20 degrees or something like that. It is called "Ice water" (something like that) and comes in a big, blue metal can with a handle on it. There is also a product called "water wetter" in a red bottle that works great as well. Always try to get to the heart of the problem but use those items for the meantime so you don't have to give up your DD.

 

 

Hope this helps.

Update on the Legacy: I took it on about a 70 mile round trip today, on the way out, at a stop light, the temp gauge started to slowly creep up, but when I pulled away, it went back to normal, and didn't move again for the rest of the trip. On the way back, it stayed steady the whole way. It shouldn't have moved on the way there, so I'm not convinced the problem is solved, but it's some good news.

I definitely agree with the "burping" My Legacy was very, very finicky about having air in the system...took several times to get it right. Also, when the temp starts to creep up, feel the upper radiator hose....if that isn't hot then your thermostat might either be bad or installed upside down

I definitely agree with the "burping" My Legacy was very, very finicky about having air in the system...took several times to get it right. Also, when the temp starts to creep up, feel the upper radiator hose....if that isn't hot then your thermostat might either be bad or installed upside down

Yes that "burping" is a pain. I have even removed the upper hose to make sure water enters the motor first. It is a must on a Subaru

 

Also, one time I actually bought a new thermostat which would NOT open.

 

swi66

Thanks for everyone's advice. I decided to try the least expensive route and change in the thermostat. I bought an OEM from Subaru, got down in a puddle of rain this morning and went at it. Found that the thermostat the shop put in was smaller, but more importantly, they had put it in UPSIDE DOWN!!! Needless to say, I am hopeful that with the new OEM and correct alignment, it will work well. Unfortunately, I broke off the bleed screw, so that's a new problem I have to fix. Will keep you updated. DIY all the way!