Question about 1990 Subaru Legacy

1 Answer

Engine overheating\ cools down when rpms get to 4000

Replaced thermal stat, still overheat, took it out, got second opion, installed another new one, ran good for about an hour, overheating again, but, this time i figured out that the higher the rpms got the lower the temp needle would go down. o.k. so canadian tire the first place said it's probably the head gasket and said if i want to run the car, but with no heat to take it right out and that's what they did. second guy said maybe a faulty thermal stat, doubted it was the heat gasket. he istalled the second thermal stat and i reported the high rpms thing and now he says it's obvious that the radiator is plugged. i have a parts car, so i can get that rad out or should i get the one thats in there now flushed. does anyone agree with the second mechanic? the car engine sound good and runs good with lots of power.

Posted by on

  • yadayada
    yadayada May 11, 2010

    head gasket, have a test run to see if combustion gases have entered the radiator, only the dealer will have this equip.



1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has answered 1,000 questions.

  • Master
  • 2,920 Answers

I would get a radiator flush and fill to make sure the radiator is clear and clean. it could be a head gasket if you were losing lots of water but i dont think thats the case.get it flushed out and go from there

Posted on Jan 08, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

What would make my 1997 Buick century to keep over heating I have replaced head gaskets and put in new thermostat

Let's start with the simple and make sure the coolant mixture was 50/50 and not 100% coolant. That will make it overheat.
Second, thing I would check is if there's a code for your catalytic converter or oxygen sensor. If your converter is clogged, then it builds back pressure that overheats the engine.
Hopefully that helps. That's all I can think about without actually having done the head gasket replacement myself or having inspected the vehicle. And make sure the heads were resurfaced and inspected as well.

May 31, 2016 | Buick Cars & Trucks

2 Answers

A/C recharged and thermostat replaced, now engine over heats in first 20 minutes of use. After 15 minute "cool down", engine runs fine and in normal temp. zone.

check that there is no air lock in the cooling system
check if the thermostat was installed with the body of the unit facing the block and not the hose

Jun 07, 2015 | 2007 Suzuki Forenza Sedan

1 Answer

2000 Toyota Avalon start car idles at 2000 rpms then starts to overheat.

First thing first, change your radiator thermostat, but make sure someone does it after the car is completely cooled down. Youll need to replace or top off the radiator fluid. If you are mixing the radiator fluid , make sure to use distilled water if it is concentrated fluid and asks for water. There are too many minerals in spring or tap water. If your car really is overheating,its a must to change your oil asap. A took an auto shop course where the instructor said that when a car overheats, the engine oil breaks down and deteriorates, and becomes no good. Everytime your car overheats= oil no good.
also check and make sure your radiator resevoir is full to the right line cuase maybe it just needs new fluid or if its been 50 -70k on the same radiator fluid, I would have it flushed, there could just be an air bubble in the line.

Mar 02, 2014 | Cars & Trucks

1 Answer

97 aurora overheats new stat flush system oil not milky or over filled new cap still overheat but when i put the cap on half way tighten i dont overheat whats my problem

Was the engine overheating before you replaced the thermostat ?
By not putting the cap on tight, you are not allowing the cooling system to build up pressure. So it could be a restriction somewhere like a radiator hose.

Apr 23, 2013 | Cars & Trucks

1 Answer

Bleeding air from 5.3l cooling system

it sounds like the temp sensor maybe bad. I actually just replaced one on a 2001 chevy doing the same thing. reading that it was running hot while stopped but fine while driving.

Feb 02, 2013 | 1999 GMC Sierra

1 Answer

Installed new waterpump and now something weird happening!

sounds like the air in the cooling system was not all bled out , it should correct itself after a few drive cycles, if not then there is more than likely a problem with the thermostat sticking in the closed position.if there is not sufficient coolant inside the cylinder head then the tempature at the thermostat will not be enough to open it therefore the cycle of the coolant will cease causing an overheat and possible engine damage.

Jan 26, 2010 | 1999 Volkswagen New Jetta

2 Answers

Engine overheating in traffic or when idling

I'm assuming your car has the Northstar engine?.

Strangely enough,if you remove the thermostat in the Northstar engine, it will overheat, this is because the stat is both a thermostat and a pressure valve.I can't be bothered to explain in detail how the whole cooling system works but please understand that you need to put the stat back in,(or preferably a new one).As for the cooling fans,what you described is normal for the Northstar.
Further to this, look at my profile,I have provided similar solutions for overheating problems.

Aug 16, 2009 | 1997 Cadillac DeVille

3 Answers

2004 Jeep wrangler 4.0 - 6cyl overheating

I had the same overheating problem in my jeep ! My problem was finaly found out to be the clutch in my fan its a different kind of clutch system it work as this. When your jeep gets warmer the tighter your fan clutch gets .While cool your fan moves slowly. now to test your clutch just warm up your jeep and rev it up a bit if your fan dose not pick up speed then it is sliping.What will come out of this is that you fan will the seez and run full all the time. if you jeep dose not overheat wile moving then it is not your thermo stat period.

Sep 02, 2008 | 2004 Jeep Wrangler

Not finding what you are looking for?
1990 Subaru Legacy Logo

211 people viewed this question

Ask a Question

Usually answered in minutes!

Top Subaru Experts


Level 3 Expert

79865 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Brandon Johnson
Brandon Johnson

Level 2 Expert

251 Answers

Are you a Subaru Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides