2001 Subaru Outback "Overheating " Problems

[jneuman]

I have a 2001 Subaru Outback (2.5 L, 4 Cylinder Engine). Lately, I have been having trouble with the car “overheating.” Whenever, I drive it around in 70 degree weather or below and between approx. 25 mph and 45 mph, the temperature gage will go from being halfway to the ¾ mark and it stays at the ¾ mark. It does not matter if the AC is on or off and it will not act do it when it is warm (I live in Phoenix so the mechanics I take it to have not been able to duplicate the problem). When I step on the accelerator hard, the temperature gage will immediately drop back down to normal but will also go back up within a couple of minutes if I continue to drive as described above. If I drive at normal highway speeds, the temperature will eventually go down to normal.

 

I have had to replace the head gaskets in this car already (6 months ago) and my mechanic has checked them and they appear to be fine. When the head gaskets were replaced the timing belt, water pump, and thermostat were all replaced too. The radiator has also been checked and cleaned out. And the fans have been checked and they work. Does anyone out there have any idea what may be going on?

 

Thanks!

[nipper]

radiator cap?

 

 

nipper

[idosubaru]

First thing is to make sure the fans are coming on when it's running hot. Might be a fan or relay.

 

Headgaskets replaced:

Use a Subaru OEM thermostat only - the difference is amazing just looking at them. The aftermarkets all look like a 2 years olds toy.

 

Was the conditioner added? Subaru requires it on these engines?

 

Have the radiator properly bled or burped, these engines are notorious for running hot after engine work because of air bubbles in the system. Although typically they actually overheat with an airbubble, not just run hot.

 

Hopefully a Subaru headgasket was used? The aftermarkets aren't considered a good bet on these motors.

[nipper]

How was the radiator "checked out" ?

 

PS was it an OE thermostat that was put in the car or aftermarket?

[bgambino]

I would like to know how your mechanic "checked" the headgaskets.....just looking for external leaks won't cut it

 

it sounds like when you rev the engine to higher rpm's it cools down...that would lead to believe that more water is circulating thus better cooling....

 

could the water pump be defective...seems remote (and if he used a subaru pump I really doubt it,,,,but I'm sure he used an aftermearket)

 

Could be the beginning of a head gasket problem ...that's why the over heat condition is minor

 

It's hard to believe it's an air bubble/pocket as it was so long ago that the system was filled

we need to know if your fans are coming on

If they are, do the thermostat and see what happens and maybe the cap like nipper suggested (use subaru parts only)

[nipper]

I would be surprised if this is a HG, as running hot is usually an aftermarket T stat issue or a tired radiator cap.

 

Lets cross our fingers.

[bgambino]

I would be surprised if this is a HG, as running hot is usually an aftermarket T stat issue or a tired radiator cap.

 

Lets cross our fingers.

 

 

nipster....what about that potential heated seat project? Are you going to attempt it or freeze your hiney this winter

I am definitely getting a remote starter this year...but a heated seat would be nice

[bgambino]

nipster....what about that potential heated seat project? Are you going to attempt it or freeze your hiney this winter

I am definitely getting a remote starter this year...but a heated seat would be nice

 

 

 

Never mind nip....I see your reply...and here i thought you were drinking too much tonight...LOL...it's me who NEEDS a drink!

[GMZ]

I am sorry if I am doing it the wrong way.

I am new to this forum and couldn’t find another way to post a question.

 

I just bought a 2001 Outback with a 2.5 engine, it has 140,000 mi.

Within about 3-5 miles on the highway it started overheating it got right up to the last line (never got into the red). Both fans are on. As I turned the heater all the way up it quickly cooled down.

 

I went back to the dealer I bought it from and he replaced the thermostat with Subaru OEM part.

 

This time I was able to go about 10 miles before it started overheating again, I did the same thing as before. Turned the heater on at full blast and it quickly cooled down to normal temp, and stayed there all the way back to dealer. There is no external leak of antifreeze anywhere.

 

What do you guys think?

Edited July 8, 2012 by GMZ

[idosubaru]

at this point the important test for your car is hydrocarbons in the coolant. auto parts stores sell block test kits like this:

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7001006_0361139896

 

that is the test they should be doing, not installing a thermostat, that was a pretty lame guess.

 

What do you guys think?

i'd be taking the car back to the dealer immediately and see what options there are for a different car or getting your money back.

 

this car is prone to headgasket issues - very, very common. type in "EJ25 headgasket" into google and watch the thousands of threads pop up, it is a huge issue and well documented. just keep in mind that not all EJ25 headgasket issues are the same - there are 3 common variants.

 

actually Subaru originally offered an extended 100,000 mile headgasket warranty on the vehicle you bought because the issue was so prevalent.

 

the problem i see here is that your generation EJ25 (there are variances) engine does not overheat. they usually leak externally and won't overheat until they run low on coolant. what you're telling us is that you are having non traditional issues which suggests a few things:

 

1. the headgaskets were previously worked on

2. the engine has been severely overheated

 

either way - there are strong indications here of not just headgasket issues - but something abnormal about that engine and possible prior severe overheats or an improper headgasket repair.

 

*maybe* it is something simple but given that you just forked out an inordinate amount of money for this car off a dealer lot you should not be walking home with a basket case headgasket issue after paying dealer lot prices.

[GMZ]

Hello grossgary.

 

It seems to me, if the head gaskets were blown, than turning the heater on would not help at all, the engine would still overheat. I think that the fault is in the radiator, but maybe it is just a wishful thinking… I really like that car. I am going to the dealer tomorrow and if he refuses to do it himself, I plan to buy the block leakage test kit at my own expense and run the test myself.

 

Any more pointers?

Edited July 9, 2012 by GMZ

[GMZ]

Dealer just called back and said his mechanic spoke to his friend who is a mechanic at Subaru dealership.

He recommended to replace the fan relay suggesting that they were kicking in too late.

 

So they replaced the relay and the temperature censor. Dealer sais the car is running normally now, no overheating at all.

Will go check tonight, will take it for a long drive on the toll way.

 

What do you guys think?

[GeneralDisorder]

Dealer just called back and said his mechanic spoke to his friend who is a mechanic at Subaru dealership.

He recommended to replace the fan relay suggesting that they were kicking in too late.

 

Makes no sense. When the car is moving it doesn't (shouldn't) need radiator fans at all. Thus they wouldn't be the cause of an overheat while driving.

 

So they replaced the relay and the temperature censor. Dealer sais the car is running normally now, no overheating at all.

Will go check tonight, will take it for a long drive on the toll way.

 

What do you guys think?

 

I would suspect they have bandaided the car in some way - drilled holes in the thermostat or gutted it, put some HG sealer goo in the system, etc.

 

How do you know when a used car dealer is lying?...... Easy - his lips are moving!

 

GD

[GMZ]

Thank you for your responce.

 

Your answer makes sence.

 

My undestanding is, even if fans did kick in too late the engine should of cooled down after they kicked in.

[idosubaru]

the fan/relay attempt seems very strange to me, i'm with GD on that one.

 

if it's a radiator issue then it should be really obvious and predictable - like it won't overheat at night (when it's cooler) and it does overheat during the day, or overheats much quicker...or overheats with A/C on but not with it off...etc. additional loads should have a direct relationship to whether it overheats or not.

 

what is scary about this predicament is that you *bought* a vehicle with a known problem. the problem itself isn't a big deal but obviously someone dumped this car with overheating issues...how many times was it overheated before you bought it?

[GeneralDisorder]

My undestanding is, even if fans did kick in too late the engine should of cooled down after they kicked in.

 

It's pretty simple to monitor the fan's - just plug a scanner into the OBD-II port and watch the temp. They should cut in at about 205* F.

 

When the vehicle is in motion - anything above about 20 MPH - the fans are superfluous because the forward motion of the car pushes air across the radiator. The fans SHOULD NEVER have to be on while the car is moving as the temp should regulate to about 190* F on it's own. Subaru uses a cold-side-controlled thermostat of about 170* - assuming a delta of 20* across the radiator you should see a hot side temp of about 190 - which is where the coolant temp sensors are located.

 

GD

[GMZ]

Thank you guys.

 

I returned that car and will probably look for some other then Subaru AWD vehicle.

 

Thanks again.

[BobKat]

Here's a weird one for you all in line with the now old questions and topic of the so-called over-heating problem referenced here. If there's anyone out there with an answer I would surely appreciate it and it may help those who have posted what I consider to be a similar problem in this question/topic:

 

I own a 2004 Subaru Outback, 2.5 liter H4 engine, manual transmission, CA emissions compliance.  I am a former auto technician and though not an expert on the latest technology, I know a lot. The car has 220,000 highway miles on it. a few weeks ago I replaced the head-gaskets with Felpro Improved designed gaskets, timing belt and all associated parts, the clutch, rear main seal, O2 sensors (part of the problem) water pump, thermostat (Duralast fail-safe), cam and crank position sensors, spark-plug and wires and the engine temperature sensor.

 

I commute 150 miles a day to work and the job seems to have gone well - the heads were leaking but are no longer doing so. There are no leaks. However the O2 sensor, bank 1 triggers the same OBD2 code at around 400 miles, Prior to changing the 5 O2 sensors the warning light would activate within 100 miles. The cruise control still won't stay on. And I have to very weird temperature sensor problem:

 

As I read that a slightly malfunctioning temp sensor can result in the O2 warning, I changed it with a new one when I did all the engine work recently. It was a WELLS SU4300. There's absolutely no reason these days to rely only on Subaru parts as in most cases these parts are supplied by the very same manufacturer that sells the so called "after-market" part.

 

Prior to the "engine rebuild" I discussed my temperature gauge start at base and gradually rise to the mid-point after warming up and stayed there. After the rebuild during which I installed a new temp sensor, I was surprised to notice the temp gauge going to the mid-point and much to my dismay climbed well past the red-line. I noticed this as I was test driving it after checking everywhere for leaks and found none. I quickly went back to my shop and parked, turned off the engine, popped the hood and looked for signs of over-heating. There were none. I hadn't driven far so I thought maybe there was a pocket preventing the thermostat from opening. I felt the lower radiator hose which seemed at first to verify my concern as it was cold in contrast to the upper hose. However the radiator fans hadn't come on - so did I have a wire unplugged? I didn't. I started the car again and the gauge went to mid-point for a couple minutes, then rapidly went over the red line. I let the car idle hoping if there was a vacuum bubble it would clear and the thermostat would open and /or the fans would run. I kept feeling the lower hose.

 

In the time I would expect for the thermostat to open with it idling, the lower hose finally got hot indicating the thermostat opened. The fans still hadn't come on. Still no sign of over-heating. After about 15 minutes the fans came on for about a minute and stopped. The engine was not over-heating as indicated by the gauge. I turned the engine off and let it sit for about 2 hours. I then put the old temp sensor back in, started the car and all was good as I drove the car to work for about three weeks with the gauge reading normal. I got a refund on the temp sensor as it was apparently defective.

 

Since the O2 warning still was happening around 400 miles and the cruise control still would shut-off, I ordered another new temp sensor from a different autoparts store. I got another Duralast/WELLS SU4300. I installed it yesterday and noticed that when I activated the ignition without starting the engine the temp gauge went to the mid-point immediately. The engine was stone-cold.I started the engine and within about ten minutes idling the gauge read above the red line. So two defective sensors from two separate suppliers? Same part number? I called the auto supply store told them my car and asked if the part number was correct? Only one sold for my car. I let the car cool, put the old sensor back in and it's back to the normal mid-range.

 

So what I know:

 

1) Engine not over-heating.

2) WELLS SU4300 the only temp sensor available for my car.

3) Old sensor corroded and it needs to be replaced sometime.

4) All new sensors read over-heating when that's not true.

 

What am I missing? What could be the problem??? I don't doubt the old sensor needs to be replaced, but the way the new ones act am I forced to depend on the old one forever until it decomposes?

 

 

 

  

[ashraf]

the problem is in the system design. the location of fan sensor is wrong so it must not be over the motor heads but it must be at the radiator. the easiest way to solve the problem by removing the thermostat from its original place and put a new one at the water exit pipe from the engine, you may use thermostat that used inside tube like renult 5 thermostat. then the system will work correct.
the problem is because the thermostat located between the engine and the radiator so one side hot and one side cold, and as the cold water pass the thermostat it will not open as required to cycle water and the engine will remain hot and the fan heat sensor will ask the fan to work while the water in radiator is cold and this will make the water goes to thermostat colder and make it to more close while the hot water trapped inside engine as it is very hot and no water cycle. if we change the place of thermostat to water exist side from engine, then both sides of thermostat will have hot water and will not close until the all water in the system become cold and the water cycle will be perfect and the engine wont become with excess heat.  so it is design mistake.

[1 Lucky Texan]

the above may be why the subaru t'stat needs a larger wax capsule;