Hello,

when driving home this even I would only have heat when driving and cool air when idling. About 5 minutes later in stop and go traffic I started over heating, as I drove temp would go back down. Coolant levels are fine, I did however notice over the last few days a faint coolant smell but was not too worried since my coolant level appear to be remaining at the same level

Would this be a thermostat? It is a 2002 Subaru Forester

 

Thank you,

Denise.

Edited December 5, 20169 yr by 1995SubaruImpreza

What kind of car?

Sounds like a bad heater core to me.

 

No heat when at idle because there is a restriction in the heater core and the water pump isn't spinning fast enough to push enough hot coolant through it.

 

And over heating when cruising because there's not enough hot coolant getting down to the t-stat and it's not opening properly.

 

You could try a oem or oem style t-stat but I doubt it would fix it.

Sorry 2002 Subaru Forester

Sounds like low coolant to me. Where are you checking your coolant level ? The overflow tank is not the place. Must open the radiator cap (engine cool) to know how full you are. Your heater core could be leaking as said OR... your head gaskets could be  externally leaking onto the cat. 2002 ej25 are known for this. 

I will check the coolant level in the radiator, the overflow is full for sure. I am not with the car right now, but I will check and post back.

Update, overflow tank is full, rad took about 1/3 a jug of coolant. Fan is kicking in... Any suggestions?

 

Thank you,

Denise

100% not a thermostat. Waste of time to replace that just for this issue alone.

 

That engine requires Subaru Coolant Conditioner. That should be added if it's never been done before or unknown.

 

You were low on coolant. The radiator was low due to:

 

A. A leak somewhere.

Look for leaks and keep it topped off.

Or

B. It's pushing coolant from radiator to overflow then overheating.

Thats probably headgaskets but Check/replace simple things like radiator cap

 

Keep an eye on:

1. Radiator level

2. Overflow level - is it filling up?

3. For spots under the car. Park over cardboard if you can.

 

Was the overflow really full/too high when you checked it?

 

Have/when we're headgaskets replaced?

Run over temp when low on coolant, headgaskets get damaged.

 

Never ignore coolant smell.

 

To check coolant level, look at the overflow. Also sharply squeeze the upper radiator hose. Normal to hear the giggle pin in the thermostat. Normal to hear maybe a little gurgle of bubbles, but monitor this. This is a before every drive check at this stage. If there is less air each time, things are ok. If there is more, that's bad.

 

It's also tricky to get all the air out of the system. Look for threads discussing burping. It is not as simple as just adding coolant.

As far as I know the head gaskets have never been replaced. Over flow tank was full to the top. I will monitor for any leaks under the car, but haven't noticed any spots under it. I will definitely get some of the Subaru coolant conditioner, and check for air.

 

Thanks again,

 

Denise Hughes.

After putting in first Subaru conditioner and still having a leak I put in some Pour and Go Blue Devil, no more leak but heat comes and goes in mine.  It could be a long winter in the north.  https://www.awesomestories.com/images/user/57c3a6d716424c3347f7e8c651a4d021.jpg

don't trust the overflow, check in the radiator neck - should be very full under the cap (check carefully)

 

fluid filling the o'flow or even out of the top of the tank usually indicates a headgasket leak.

Sounds like what my 98 Outback was doing when the head gaskets went. Which I replaced at about 150,000, by a guy who basically does only subie head gaskets, and she's been good as new since then. Big chunk of change, though. Good luck with the Forester.

It could be as simple as a bad radiator cap.

 

Check the coolant in the radiator after the engine cools down. Sounds like it needs at least a half gallon.

 

If you smell coolant that means you have a leak somewhere. Most common place I would look in cold weather is the clamps on the upper and lower radiator hoses. When it gets cold the clamps need to be tightened up sometimes.

 

Bad Head gaskets are common on that engine, unfortunately. But check everything else first.

***Update***

 

Brought it into the shop, they did a coolant system flush and said it was in pretty bad condition. Replaced the rad cap and thermostat and pressure tested the system. No leaks found and everything was fine...or so it seemed. 

On my drive into work today, I am noticing at idle the heat is going again. So far it has not started over heating, but if it anything like last time the drive home will be when I start overheating. I have not checked the coolant level in about a week, but will before I leave work.

Leak - pressure test at shop and no notice of leaks suggests it's not leaking

Radiator cap - check/clean where it seat on and inside the radiator to make sure it's clean. 

 

Make absolutely certain it's properly burped. they can be annoying and unforgiving with any air in the system.

 

Otherwise it sounds like it's headed towards an internal headgasket breach pushing exhaust into the coolant.

 

Typical signs are loosing cabin heat followed by overheating.

Checking once every seven days is six days too long when verifying cooling system problems. Pressure test will almost never show the beginning headgasket leak that slowly puts air into the system.

The saga continues...

 

The car is in at the mechanic and as everyone has been saying all along...internal headgasket leak.

 

So my question now is, is there anything I can do to prolong the inevitable...

 

Mechanic is quoting about 2300.00 (cdn) 1750.00 (usd), which at least sounds reasonable...

 

The car also has a check engine light on (P0420) - from my recearch on here could quite possibly be an O2 sensor (?)

 

Also thinking ball joints/tie rods and at least one wheel bearing will need to be done as well (mechnic will confirm tonight)

 

So do I bite the bullet and fix the car, or do I let the poor thing go to rest?

 

155,000 miles on the car, body has some rust in the wheel wells but other than that it is in pretty decent condition.