Thermastat

spoore · Post by **spoore** » Sat Nov 29, 2003 11:57 am

Here is the deal. My Legacy wagon has been blowing cold air ever since I got it a couple of months ago. A week ago I got a new thermastat to put in and when I took the old one out there was just the nipple with the gasket around it and no thermastat. I thought this is it. I put the new thermastat in and ta da I had heat. The next morning I'm on my way to church about 10 miles from the house the car overheats. I took it to a garage and had the water pump changed and a timing belt put on and the guy put in another thermastat he said the one I had put in was bad when I bought it. Cool problem solved. So I drive it all week and it works fine. Until Thanksgiving day I decided to drive the car to my moms and then to the inlaws which is about 100 miles round trip. It did fine all day, but on the way home the temp gauge pegged and it overheated again. I parked it. The only way I can keep it from overheating is to run it without a thermastat. Apparently that is why there was just a nipple and gasket in there to begin with that is the only way to keep the gasket in there so you don't leak water. Any ideas on why with a thermastat it overheats and without one it doesn't. I need heat in a bad way. Could my temperature sensor be bad and sending the wrong data to the computer.

I know this is long, but any help would be greatly appreciated I have two little girls and it is hard to ride in this kind of weather with no heat.

vrg3 · Post by **vrg3** » Sat Nov 29, 2003 2:31 pm

I can't diagnose your actual problem, but I do know that running without a thermostat will mask a lot of problems since it makes the radiator work overtime cooling the engine. Your cooling system problem is somewhere else in the cooling system.

Did you try a cooling system flush to see what came out?

Do you lose any coolant?

Have you tried checking for any air bubbles, and burping them out through the bleed screw and radiator cap?

JasonGrahn · Post by **JasonGrahn** » Sat Nov 29, 2003 3:16 pm

this sounds exactly like what happened to me when my head gaskets went away. I would definitley check your coolant level and smell your radiator cap. Does it smell like exhaust? Also, after driving for a bit (15-20 minutes, is one radiator coolant hose hot and one cold?

This what i replaced before i did my head gaskets: Temp Sensor, radiator cap, thermostat.

if it's possible, do a radiator pressure check and a leakdown test of the cylinders. Flushing the radiator would be good too, as you might have something clogging the paths.

spoore · Post by **spoore** » Sat Nov 29, 2003 4:39 pm

I had the system flushed and filled when I bought the car, but that was just at the local Valvoline quick oil change place so they hooked there machine up to it and pumped the old fluid out and the new fluid in.

The guy that put the water pump and timing belt on said that the Head gaskets were OK because it was building up pressure. I do seem to be loosing coolant slowly, but I can't see any visual drainage from the car there is no water in the oil and no steam out the exhaust. One mechanic told me that I might have a slow leak into the combustion chamber.

How do you test to see if the head gaskets are going out or gone out. Would that cause the thermastat to stick though.

Are the temperature sensors very expensive? I will probably replace that and then put the thermastat back in and see what happens. I just can't figure out what would make the thermastat keep sticking. I know one thing I wish they would have put the thermastat on top of the engine instead of the bottom. What a pain.

spoore · Post by **spoore** » Sat Nov 29, 2003 4:47 pm

The more I think about it the only difference with the thermastat being in or out is the pressure right. If there is no thermastat there is no pressure. When I put the thermastat in then there is pressure for the water to get through the thermastat and it causes something to happen which makes it overheat.

newfielady · Post by **newfielady** » Sat Nov 29, 2003 5:29 pm

I had the exact same thing happen to me last year. I took it back to the shop that changed the water pump for me. They couldn't find anything wrong with it. I also took it to a radiator shop thinking this might be the problem. They changed the thermostat and it still ran hot. After 3 thermostats, a week with no car I decided to check the internet for help. I came across this board and a fellow named josh that helped me out. All that needed to be done was to burp the radiator. It took several times and a broken bleeder screw but I finally got it burped. It never ran hot after that. You might have to burp it, turn it off wait for it to cool down and burp again several times but it is sure worth the effort. Don't let it get too hot because you don't want to damage the engine. Hope this helps. I couldn't believe it was something so simple after it was fixed.

evolutionmovement · Post by **evolutionmovement** » Sat Nov 29, 2003 7:28 pm

I second the air bubbles. I think it takes a little for the air to collect in one area and cause a problem, so that's why it takes a while to come back after changing something.

Steve

spoore · Post by **spoore** » Sat Nov 29, 2003 8:06 pm

How do you burp it? Where is the bleeder screw?

THAWA · Post by **THAWA** » Sat Nov 29, 2003 8:17 pm

Assuming you don't have a turbo, the bleeder screw is a little thing on the passanger side of the radiator where the upper hose connects to it. Check you manual for all the instructions.

vrg3 · Post by **vrg3** » Sun Nov 30, 2003 12:55 am

The thermostat is meant to regulate temperature by controlling flow through the radiator. When the coolant gets hot enough, the thermostat opens, allowing passing air to cool it. Without a thermostat, passing air is always cooling the engine no matter what. That's why removing the thermostat can mask cooling system problems.

The thermostat doesn't control pressure. Pressure is regulated by the radiator cap.

newfielady · Post by **newfielady** » Sun Nov 30, 2003 5:01 am

Look on the right hand top of the radiator and you will see what looks like a screw. Run your car until operating temp.

Stop the car and loosen the bleeder screw. There should be alot of steam. (BE CAREFUL).

Take off the radiator cap and fill the radiator. Coolant should
start to flow out the little screw hole. This is what it should be doing.
It may take a couple of goes to do it. Good luck and I hope this helps.

THAWA · Post by **THAWA** » Sun Nov 30, 2003 6:56 pm

is this the correct way to do it?

ciper · Post by **ciper** » Sun Nov 30, 2003 8:15 pm

Not the way is usually done. I say you find the steepest hill and park it. Park on it so that the radiator cap is slightly higher than the bleeder screw if possible. Run the car while cold for a few minutes and shut it down. Open the rad cap and bleeder to get air from both sides. Fill until it spills out and replace the screw. Keep filling.

CCorsair · Post by **CCorsair** » Mon Dec 18, 2006 8:40 am

If you don't bleed the air would this cause the engine over heat till there enough coolant in the system?

Had a hose blow out on the top hose . forgot about the bleeder screw. I keep remembering some about air in the system causing problems with the thermostat.

engine is running fine today no over heating no coolant leaks or water in oil or vs versa. No leaks in the water pump or head gaskets found . Will be getting thermostat replaced ASAP,

CC

douglas vincent · Post by **douglas vincent** » Mon Dec 18, 2006 7:43 pm

Also, make sure the thermostat was put in the correct way!

Post by **Legacy777** » Mon Dec 18, 2006 7:45 pm

If it's a subaru thermostat, it'll only fit one way......ANOTHER reason to use an OEM subaru thermostat.

CCorsair · Post by **CCorsair** » Mon Dec 18, 2006 8:10 pm

Drove the car today to get wife to work it did not over heat.
it ran normal and seem to stay at the same temp.

Check coolant where i got in it was at level in both radiator and overflow. top hose was hot but the engine and coolant was not very hot at all . did run the heat /def all the way there and back made on one stop for 10mins for gas .. did freeway there and street route back to see if I could make it over heat.. it didn't.

I called the one shop i used before they said it could be head gasket i cringed at that as he said $1,500 for that....

I think i will start with the fans and thermostat then have check the rest. I feel the engine is running good it has one problem starting but can say if it is sticky starter or the the Alarm system as it seem to happen if you try to open the door on the driver side when its locked. Other than that i see not signs that i will over heat again but I will have then change the thermostat
plus check out why the fans are not cutting in to cool the engine. with the fan running it seem to keep the whole engine nice and cooler. It is colder here right now it was like in the 20's this morning so I happy I put in the antifreeze and got the water out.

will have the change out the bottom hose in the system too as i think it best to have newer than older. the radiator is newer after market and bigger than the stander one.
this could be why one fan does not kick in but the main fan stop after a injector died .. could be related maybe? it run only if the A/C or heat/Def is on.

ok Thanks will let all know what i find out Wed .. Everyone pray it just the thermostat and sensors on the fans.

Cheap fix please

Thanks

CC

subytech · Post by **subytech** » Tue Dec 19, 2006 2:59 am

Were the fans running when the car overheaded? The fan on the passneger side of the car is sapposed to run when the A/C pump is activated (in AC or heat/defrost mode) Traditionally in cool weather it takes a LONG time for the cooling fans to kick in if the car is just sitting.

CCorsair · Post by **CCorsair** » Tue Dec 19, 2006 6:10 am

subytech wrote:Were the fans running when the car overheated? The fan on the passenger side of the car is supposed to run when the A/C pump is activated (in AC or heat/defrost mode) Traditionally in cool weather it takes a LONG time for the cooling fans to kick in if the car is just sitting.

When we got the wagon I noted that only the one center or main fan kicked in during any given time. I the shop said the radiator is a newer one that is bigger than the stander and could keep the other fan from coming on .. my wife was running with the heater/def on so the fan was most likely going at the time .

On payday I having the thermostat changed and the fans and sensors look at and see why the are not kicking in and fixed .

The wagon had done well since I got the coolant to the right levels( the shop said it could have been that but the guy said he is worried that the heads could have got damage which I praying they didn't.

I had the #3 injector got out some month back at that time I noted that the main fan the one on the driver side or center) stop coming on with the engine. Also at that time the A/c Died as well but that was due to this car was driven in San Fransisco
where the owner did use the the A/C at all and the car was parked for some time.

There is some electrical gremlins in the car as there is an alarm system no one knew about or at lease the last owner did know about it.

I wondering if this wagon is going to be worth keeping going?

I really love this wagon and how it drives i just with i know more on how to work on the engine than the electrical.

any info is great to have when going to the shop to get this fixed .. saves me $$ on them trying to figure it out.

The said i save $100 by doing my own diag on the the injector last time.

Ok thanks for all the help people

CC

CCorsair · Post by **CCorsair** » Thu Dec 21, 2006 5:53 am

GOOD NEW!!!

All past in the thermostat and the heads.
Wagon is in good shape and I need to replace the Aux fan and the Main is work right as well. the shop did a once over and found no problem but for small oil leak that I can deal with now or later and that the one fan need a new motor. I can get a new one at $200+ or a used one from the salvage yard for $25...guess were i will be going..that is unless some has an extra out here.

Here a funny I randomly picked this shop off the internet as it was the only one other than a dealers ship to go to when I had an injector go out . today I ask them if they could check the frame to see if it had had any damage before and the guy said he didn't need to as this wagon was worked on by them for the last owners. Now that is a one in a million pick plus it makes me feel better about the wagon as the guy said they did all the oil changes and other work for the last owner and this wagon has a good history as being reliable.

This wagon was Craig's list buy for $1000 and I was fearing I got something with hidden problems.

Ok all thanks for the input and help
ave a Merry Christmas and Happy Hanukkah

CC

legacycentral bbs

A forum for 89-94 BC-BF(BJ) Legacy Owners and Fans

Thermastat

Thermastat