Overheating Forester

[artguy9516]

I'm having a real problem with my 03 Forester (about 98k). At the beginning of the month we had the head gaskets, thermostats, cam and crank seal, water pump, timing belt, tb tensioner, and associated "stuff" done at the local dealer. About 10 days later when driving on the highway the temp gage began to indicate that the car was overheating. The AC was on and it began to blow hot air. The needle was almost in the red. We got it to a nearby dealer (not the one who serviced it) who could not replicate our problem. We got back on the road and not 10 minutes later the car began to overheat again. We got it back to the dealer we just left and left the car with them. They had it for two days and road tested it and could not get it to over heat. We picked it up and again when driving home it began to overheat but not as severe as before (I was at work and my wife who drives the car regularly picked it up.) any thoughts???

[edrach]

Take it back to the original dealer and start documenting the times, conditions, and everything else. If this isn't resolved to your satisfaction contact SOA.

 

This could be as simple as an air bubble in the coolant (which should have been cleared after the first, AND Second trip to the dealer). You might also be due for a new radiator (which would be on your cost); but if the car overheats due to the radiator being bad, the cost of the new headgaskets and repairs would be on you. So get it done right.

 

Don't let this go; take it to a reputable dealer and negotiate a loaner car or use your insurance to get a rental while you have it fixed correctly.

[idosubaru]

details of what the vehicle is doing help tremendously online. the good thing is that there is more subaru specific experience here than anywhere else in the world, so you're in good hands. but we need info...give it to me, give it to me! if a living, breathing, sighted, non hearing impaired, ASE certified Subaru mechanic can't diagnose it with it right in front of him, our job is much harder without details.

 

these are mostly really simple and you should be able to answer or figure out:

 

1. any coolant loss? is the reservoir empty or low?

2. is the radiator level low (check it, don't assume it and the reservoir are the same)?

3. when it starts to overheat - do the electric fans turn on under the hood? very simple to check - when it starts to run above normal, pop the hood and look at the fans - they should both be on.

4. when you turn the a/c on do the fans turn on (at any time, even after start up)?

5. when it overheats is one radiator hose significantly hotter than the other...keeping in mind that things are really hot..be careful or ask your best friend to check for you!

 

if it starts to run hot DO NOT leave your a/c on, turn it off immediately.

 

good luck!

[artguy9516]

thanks for the recent replies

 

in terms of item 1) no coolant loss

2) my wife reports that she can see coolant inside the radiator when she took off the cap

 

3) the fans run when the engine is hot.

 

not sure about 4 and haven't checked 5

[Gloyale]

Curious as to why the head gaskets were replaced to begin with? That isn't normal maintenance. Was it overheating before? Was it a warranty repair? ussualy, the dealer will only replace whichever side was bad, not both?

 

Is it possible you meant Valve cover gaskets? If so, it may be that you have a headgasket issue.

[artguy9516]

Both head gaskets were replaced as part of a warranty repair

[idosubaru]

i would have the thermostat replaced and make sure it's a Subaru only OEM thermostat.

 

the only intermittent failures i can think for this motor would be the thermostat and air bubbles getting introduced into the coolant.

 

how bad was the engine overheated when the head gaskets were replaced the first time? it's possible the engine suffered severe damage then - cracks in the heads or worse the engine block. unfortunately subaru doesn't do good head gasket jobs, they typically just gasket-slap them particularly on newer cars like yours. no measuring of flatness, no milling, no pressure testing.

 

if you still want to diagnose, check these questions out:

 

when it's overheating, while running or immediately after turning the car off - are there bubbles in the overflow reservoir?

 

does it ever overheat with the a/c off?

does it overheat when idling, moving or both?

does it overheat only when the temperature is high outside?

when already hot - will it cool down when idling or moving?

[johnceggleston]

did the car have the 'special coolant additive" put in the radiator prior to the head gasket work. IIRC, that was a pre-requisite of warranty HG work.

 

your radiator may be blocked. i have heard of this happening after the HGs are done in cars with the 'stuff' added . if this is the case, a good rule of thumb would be to flush your cooling system when doing HGs if you have put in the "stuff". ihave read where stop leak only hardens when exposed to air, guess what happens when you drain the system to do the HGs.

 

i course, i could be all wrong. please correct me if i am.

[idosubaru]

your radiator may be blocked.

i would think this would be a more consistent problem, not come and go.

 

but that's why i asked those questions - if it's load dependent (outside temps, a/c, idle, driving, climbing, or others), then it could be a radiator.

[aircraft engineer]

I'm no good on Sub HGs but I work with a guy who had an engine O/H done at the dealer and they put both HGs on UPSIDE DOWN (Nissan V6) It kept overheating and they couldn't figure out why - HE tore it down (documenting EVERYTHING with pics off his digital camera) and took it to them and gave them the bill - which they PAID - so even dealers can screw things ROYALLY

[nipper]

Im voting for an air bubble.

 

This is what you need to do. Get a gallon of premix coolant. With the car off remove the radiator cap, and open the bleed valve on the other end of the radiator. Start the car. You shold see a splurge of coolant come out of the radiator when the Tstat opens. Start SLOWLY topping off the coolant. shut the car off, let it cool down, top off the coolant. Replace the cap. If you are comfortable with draining the coolant, i would prefer you drain the coolant from the raidator, close the drain. Start the car with the cap off and slowly add coolantwhile the car is running, follow my instructions above.

 

They just dumped coolant in the car, and did not take thier time.

 

 

If you take it back to the dealer, YOU drive the car and show them the gauge is peaking. Record your mileage. i am betting they are just letting the car idle in the lot, and not really taking it for a good test drive.

 

good luck

 

nipper