Overheating and engine gasket question

:cool:Hi,

 

I have a 1997 Legacy Brighton auto 2.2 L with 83K.

 

Recently driving with window opened. Smelled coolant and then noticed temp gauge on Hot. Pulled over 1/2 mile, opened hood. No steam, engine and radiator not hot touch, few drops of coolant around rad cap. Later opened rad cap and a swoosh of air came out. Overflow tank was very low and probably sucking air. Coolant fan not operating. Later drained about 4.4 qts of radiator fluid and flushed and replaced. Thermostat was operating and there were no leaks. Will get a pressure check. Coolant fan does work with air con on.

 

Have run car in driveway for 50 min, no leaks. Even when idles for 20 min does not go above 1/2 on temp gauge and thus no coolant fan. I will drive it tomorrow and force it to get hot or make coolant fan go on.

 

1. There are kits for testing hydrocarbons in radiator; any recommendations. My thought is that if I damaged the head gasket this will tell me. (so far no bubbles in radiator or tank and fluids are stable and exhaust is clear).

2. was gonna put in Subaru radiator conditioner, which is recommended for the 2.5 L engine. Can this clog up a radiator?

3. Heard 2.5 L engines had head gasket issues. What about the 2.2 L.?

4. Anyone know of good Subaru service place in San Diego?

5. can an air bubble cause the gauge to read hot while in reality the 4.5 qts of radiator fluid I had in the radiator were ciruculating and doing the job?

6. Could the drops of coolant around the cap been caused by the expanding air in radiator system pushing coolant out of radiator cap?

7. If you were me would you be concerned yet?

 

 

 

thanks

Was the gauge bad? The fan should have been going like crazy at that point.

It is possible that the fan relay or temperature sensing unit is defective, which would cause the cooling fan not to work. I will ride the car more today to make it get hot or make the cooling fan go on. I think the temp gauge works and have a theory that the air in the radiator system might have caused a misreading. The gauge was hot and yet the engine was not hot to the touch. Now that I have changed coolant and burped system it seems to take much longer for the temp gauge to go to the middle; which it holds nicely without the need for cooling fan to go on.

1. There are kits for testing hydrocarbons in radiator; any recommendations. My thought is that if I damaged the head gasket this will tell me. -- Yes and No. Most times this type of tester is useless. If the headgasket is compromised to the point that it lets enough hydrocarbons into the cooling system for the tester to pick it up then usually the motor will not have enough compression to idle.

 

Also, most times a headgasket will leak only under high boost or high load.

 

2. was gonna put in Subaru radiator conditioner, which is recommended for the 2.5 L engine. Can this clog up a radiator? -- If this is from Subaru and it is meant for radiators why do you think it would clog it up.

 

5. can an air bubble cause the gauge to read hot while in reality the 4.5 qts of radiator fluid I had in the radiator were ciruculating and doing the job? -- No... if the coolant was circulating. But if the air bubble got caught under the thermostat then it could prevent the thermostat from opening and that could cause the coolant not to flow, thus cause overheating.

 

6. Could the drops of coolant around the cap been caused by the expanding air in radiator system pushing coolant out of radiator cap? -- No. More than likely it is caused by a bad rubber seal on the cap. Replace the cap.

 

7. If you were me would you be concerned yet?

-- Yes. Overheating a motor can kill a motor just as easily and completely as running no oil.

thanks for the reply:

 

Although the temp gauge said hot the engine was warm to the touch and the radiator the same. Can an engine overheat and get damaged andyet not be hot to the touch?

^No. If the thermostat was blocked then the engine would be hot to touch, if the radiator was blocked there would be a hot spot on the radiator, either way when the temp gets into the red something will give and you will know. Thats why I think the gauge is suspect. It could just be an anomaly and the gauge went back to acting correctly after a restart of the car. It could just be a bad pressure cap causing things to act funny.

So, let's say I drive the car and all is working. What type of tests should I have done to understand any damage that was done. I have an independent Subaru repair place that said for $80 they will check cooling system out and then apply that $ to repairs. Sounds good to me considering I might need a Temp Sensor if coolant fan does not work and can use new radiator hoses.

I would suspect the HG. We had an Outback of that vintage and the HG went at 59,000 miles. Very similar symptoms. Brought it to two independent shops that deal with Subarus who danced around the problem but never diagnosed the issue. We did the same things, flush, new thermostat, etc.

 

Slowly the issue will get worse and coolant consumption will go up. Those engines leak internally, the coolant goes into the cylinders and shows up in the exhaust stream.

 

It is a pretty simple test for a competent Subaru dealer.

 

If it isn't covered by Subaru, plan on spending around $1,000 for the HG replacement and if you overheated the car, which it sounds like you did, make sure they check to make sure the heads didn't warp.

 

Subaru has been taking care of HG issues for people past the warranty period. You may get it covered. I know they were covering back to 1998, but I'm not sure on 1997 cars.

 

Good luck, the HG issue sucks big time.