intermitten overheating with Subaru Forester

[lsapp@hotmail.com]

I have a 98 Subaru Forester that I need some feedback on. About 8 months ago I noticed the smell of antifreeze in the general area I was parked in. I did not pay it any mind and drove home, about 10 minutes away my gauge shot up to H. I quickly pulled over and let the car cool down. I had to do this every few miles or so until I made it home. Once the car had cooled down I topped of the antifreeze, which did seem low. I did not have any other problems until maybe 4 months ago, same scenario. The car can sit in idle all day and it will not overheat but intermittently a 5 minute drive sends the gauge to H. Any ideas? So far I have heard thermostat, fan relay and head gasket.

 

Thanks.

[WAWalker]

Classic symtoms of leaking HG's. Does the coolant recovery bottle have a black scum build up in it? Have cooling system checked for hydrocarbons.

[idosubaru]

hey welcome maryland guy.

 

sounds like headgasket. be good to know the year and mileage. the more miles on it, the more i'd suspect the thermostat.

 

sounds like it's loosing coolant at a very slow rate...you said after 4 months it did it again right? does it only overheat once it looses coolant?

 

you could have a small coolant leak somewhere (radiator cap, hose connections, water pump, radiator, head gasket) and once you loose some coolant it creates an airpocket in the system. these newer subarus are sensitive to getting all the air out to function properly. i'd look very closely for any signs of leakage and replace the thermostat.

[lsapp@hotmail.com]

Thanks grossgary and WAWalker.

 

I will check the coolant recovery tonight.

 

My Forester is 98, and it has about 160K on it.

 

I am honestly not sure if the car overheats because it looses the coolant or if it over heats for some other reason and the coolant gets too hot and then blows.

[Setright]

Before you throw bundles of money at at, try this:

 

Buy a new radiator cap, genuine part please, and remove the old one. Top off, start the engine and idle it until the thermostat opens - the coolant level in the rad neck will drop as it starts to circulate.

Top off again, mount the new rad cap, fill expansion bottle to FULL mark.

 

Keep a watchful eye on it. If it continues to mysteriously overheat, plan on replacing the head gaskets. Don't start going down the same road most of us did: New radiator, new hoses, new thermostat, new waterpump...

[idosubaru]

good call, radiator and water pump are expensive parts (particularly if you're paying someone else to do it). be sure you don't go throwing those parts at it first.

 

at your mileage i'd want a new thermostat anyway, so i'd replace it since they cost under $5.

 

i work in Greenbelt, MD i think you may be close to me. if so i would be willing to look at it for you. PM or email if yo'ure interested in me checking it out. overheating will cause sever engine damage quickly, try not to drive it hot.

[nipper]

SInce it is happening regularly check the cooling system for bubbles or the presence of exhaust gasses. I think you have a blown HG myself, but removing the cap (when cold) and starting the car, watching for bubles, it should be real obvious.

 

nipper

[lsapp@hotmail.com]

more info....

 

I checked the coolant recovery and did not notice any black scum. build up.

 

Yesterday I started it up and it ran idle for about 30 minutes, I drove it about a mile up the street and it overheated again.

 

I will try the radiator cap, and check for bubbles and let you know.

 

grossgary, thanks for the offer, I will keep you posted.

[idosubaru]

 

grossgary, thanks for the offer, I will keep you posted.

sure thing. good luck with it. the 2.5's aren't very nice in the head gasket department, lets hope it's something else.

[the_bard]

good call, radiator and water pump are expensive parts (particularly if you're paying someone else to do it). be sure you don't go throwing those parts at it first.

I can't resist the urge to play devil's advocate. The dealer I bought my '97 OBW followed this same theory... he replaced the entire engine twice (yeah, twice ). I managed to talk him into swapping an EJ22 into it at the end of all this, frustrated by the supposedly constantly failing headgaskets. He knew the original engine had bad hg's, and suspected the replacement engine had a bad set, too, and focused on just that, not suspecting that the clogged radiator was causing the engine to overheat and blowing the hg(s). At which point he'd "tunnel vision" on the symptoms of the blown hg and blame the replacement engine.

 

I pulled the radiator myself, and found it chock-full of deposits (tipped it upside down, a chunk the size of my thumb fell out. Fun stuff). This is after repeatedly asking the dealer if he checked the radiator.

 

So in my case, replacing the radiator would've fixed the cause of the problem (though we probably would've ended up doing the headgaskets again anyway, since in the process of diagnosing the bad radiator we probably would've toasted the hg's again).

 

If the car's got a lot of miles/wear on it, swapping the radiator & etc. might be a good idea as a preventive maintenance. Even if they're not the cause of the overheating problem, replacing them might prevent an overheating problem in the future.

 

'Course, if you don't plan on keeping the car around for as long as possible (unlike me) , or you don't have enough money to keep throwing at it (like me, thankfully the dealer covered the replacements under the warranty implied with the car purchase), then you get to play diagnostics...

 

at your mileage i'd want a new thermostat anyway, so i'd replace it since they cost under $5... overheating will cause sever engine damage quickly, try not to drive it hot.

Good advice. Cheap & easy-to-replace parts are a good place to start. And like I said above, we toasted the second engine in my '97 OBW since the dealer refused to diagnose the clogged radiator. Don't keep overheating it. I imagine things like seals, piston rings, bearings aren't going to like being repeatedly overheated.