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Guest Message by DevFuse

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Forester 2.5XS 2003 overheating

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6 replies to this topic

#1 Isabelle


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Posted 11 January 2013 - 09:50 PM


I bought last week a Subaru Forester 2.5XS 2003 with 168K miles. The car and the engine looked clean and nice. The timing belt was changed at 140K so pretty recently. The car belonged to a compagny for most of its mileage and I though it was a good sign as they might take good care of their cars. The woman who sold it to me had it for just a few weeks and said she'd just bought it but it was to small for her family and decided to buy a bigger one.
Anyway, the first time I drove the car the engine temperature gauge when sky high even if it was -5 F outside and I'd just drove a few miles.
Since then, I only drove it a few miles at a time. Sometimes it's ok but most of the time as soon as I drive more at than 2500 rpm - like a hill - the temperature increase really fast. On the way down (the hill) it would decrease as well as if I turn on the heating.
But when I open the hood it doesn't look that hot either. The coolant is not boiling, the engine is not smoking. It's not smelling hot or anything.
I am actually not sure the engine is hot but i can't put my hand on it to check, can I ?
I already had the thermostat changed. At that time the mechanic changed 2 hoses that he told me had gotten too hot at some point.
For the HG, I can only say that except when I start the car, there is no white smoke going out of the exhaust. A friend told me that the exhaust doesn't smell like anti-freeze. I took it as a good sign.
I checked the coolant and there is that orange stuff in it that my mechanic called a sealer. The coolant has already been changed twice (in 2 days) but that stuff's still in there. Could it clog the radiator and be the problem ?
My mechanic tell me his bet is that the water pump is not working or it's the head gasket. Anyway both are expensive and I have no way of being sure that one or the other will fix the problem. I already spent 800 dollars in that car in a week (other small but expensive stuff needed repair - like the engine for the windows). The mechanic told me that with that mileage i should just trade it or get rid of it. I read a lot of post here and from what I got it's not always THE HEAD GASKET as mechanics seem to say. There might be more simple and cheapest things to look at first.
Any advice would be most welcome.

#2 Fairtax4me



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Posted 11 January 2013 - 10:52 PM

The two biggest things are to use a Subaru OEM thermostat, and make sure the system is properly filled with coolant and purged of air.

If the thermostat didnt come from a dealer there are only one or two acceptable aftermarket replacements, and they are generally only available from online sources. Did the thermostat come from a dealer?

Secondly. Because of the design of the Subaru cooling system you have to fill the engine with coolant before filling the radiator. Otherwise the engine will airlock and there will not be enough coolant flow to keep the engine cool.
System capacity is around 1.6 gallons. If you fill the engine through the upper radiator hose, then fill the radiator you should be able to get at least 1.5 gallons into the system on the initial fill. If you just fill the radiator you may only have less than a gallon of coolant in the system, which prevents normal cooling.
There is a small plug on the upper corner of the radiator opposite of the filler cap. This plug needs to be removed (it just unscrews) while filing the radiator to allow all of the air out of the radiator. Once full the plug should be re-installed before starting the engine.
Start the engine with the radiator cap off, top up the colant level in the radiator, then put the cap on. Fill the overflow tank to about half full and allow the engine to warm to normal temperature while idling. Once warm turn the engine off and allow it to cool completely.
Once cool check the coolant level in the radiator and overflow, top up if necessary then cap off and start, allow the engine to reach normal operating temp then take the car for a short drive. If the engine overheats after this air purge process the heater core or bypass pipe may be clogged, but the head gaskets are a prime suspect.

#3 The Dude

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Posted 12 January 2013 - 11:13 AM

There is a simple, definitive test for a blown head gasket. A chemical is used to check the coolant for exhaust gas. The only way that exhaust gas can get into the coolant is if the head gasket has blown.


Definitely try "burping" the cooling system. If that doesn't work, I would test the coolant for exhaust gases. I suspect, but do not know, that you may have bought a car with a blown head gasket. The first thing is determine whether, or not, your car has a blown head gasket. If the car has a blown head gasket, the second thing is to decide what to do about it. If the car has a blown head gasket:

Did you buy the car "as is"? What are the laws in your state regarding private party auto sales? If your post is accurate, you very well could have bought a car that already had a blown head gasket.

Let's cut to the chase, worse case scenario, you're looking at a replacement engine for this car. If there is anyway to go against the seller for an "implied warranty'" in your state, you might consider taking that course of action.

BTW, the Forester is scheduled to have a timing belt change at 105,000 miles. The fact that the timing belt was changed at a 140, 000 miles makes me suspicious. Perhaps the timing belt was replaced 35,000 miles late, or perhaps serious engine work was done at 140,000 and a second timing belt was installed at that time. Hopefully, your car has a minor problem. But if it has a blown head gasket, you need to know that and act accordingly.

Edited by The Dude, 13 January 2013 - 09:22 AM.

#4 bstone


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Posted 13 January 2013 - 09:03 PM

Sounds like a non-OE thermostat was used or there is air in the system which needs to be burped out. The EJ25 is a difficult engine to burp so you may want to read around for some hints. I generally squeeze the upper and lower radiator hoses in attempt to displace air trapped in the lower parts of the system, adding coolant as I go along.

#5 ferret


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Posted 14 January 2013 - 06:46 AM

Bear in Mind, we can't SEE, HEAR, TOUCH or OBSERVE your car, so we are relying on you are our input to suggest how to fix your car.

A few things come to mind and comments here.

First, the 03 Forester has a vertical radiator, not a cross flow as many Legacy/Outbacks have. So they fill quite easily and rarely need burping.

If they did NOT use a Subaru thermostat, yes it can act this way. OEM thermostats are usually smaller ( diameter is correct, but length is shorter ) so they don't sit as far into the water jacket as necessary for uniform temperature control. So you get wide temp swings and intermittent overheating.

The radiator MAY be partially blocked. This leads to normal driving being acceptable, but when you encounter a long uphill or put any additional load on the engine, it can't dissipate heat fast enough. When the car has been run, shut it off, and feel the radiator thru the cooling fan side. It should be uniformly warm all over, no cool areas. Cool areas indicate blockage.

Finally, if/when it's hot, open the hood, with the engine running. The coolant should be HIGH but NOT OVERFLOWING from the coolant bottle. It's normal for it to expand and fill the bottle, but it's large enough that it should not come out. Open the top of the bottle and observe, is there FOAM or a steady stream of bubbles coming from the bottom of the bottle? A bubble once or twice as you race the engine may be normal, but a steady stream of small or larger bubbles indicate a leaking head gasket.

Armed with these items to observe, please get back to us and see what we can suggest from your observations.

#6 Isabelle


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Posted 15 January 2013 - 09:21 AM

Thanks for your answers. I couldn't really do what you asked me about the radiator as I don't know where the caps are.
However I finally brought the car to my regular mechanic whom I trust very much.
He did all the test and confirmed the head gasket issue.
I found a place to have it replaced for a reasonable price.
I guess I should just not have trusted the person who sold me the car saying everything was ok...
Thanks to you all for your advices anyway

#7 subaruplatt


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Posted 15 January 2013 - 02:30 PM

My buddy had his whole front end replaced by a subaru dealer. 2003 forester like yours.

There is a suspension recall on them. Don'y worry you will get either free rustproofing or a new suspension.

Are you sure that it's not worth doing at the dealer?

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