1997 Legacy - Hope it's not the head gasket

katielady22

Hi all,

First time posting here! I've been perusing the forums for a few weeks now, trying to find a definitive answer to my question, but hopefully a posting is okay too. If the topic has already been covered, I apologize.

About 3 weeks ago, my "Check Engine" light came on in my 1997 Subaru Legacy. The day after the light came on, my temperature gauge in the car started slowly climbing, as if the car was overheating. I turned on the heat and the temperature gauge went back to normal. I took it to have the code read, and the technician told me that it was either a faulty temperature sensor or the radiator fans that weren't working. My Dad and I replaced the temp. sensor a few days later, and the car wasn’t having any issues for a few days and the fans were kicking on. The problem started up again a few days after that, so I checked the fluids, added some water to the coolant tank and checked the oil to see if there was any water in that. There wasn’t.

The car is fine on long drives (20+miles) but starts to overheat when I’m idling or in stop-and-go traffic. I’m concerned that this might be a head gasket issue, but didn’t know if replacing anything else before tearing everything apart would be useful.

Thank you in advance for your assistance!

xwesx

It does sound like it is an issue of airflow - you are sure that both of the fans are running?

katielady22

Hi!

No, I'm not positive they were both on...clearly this would affect the airflow through the radiator? And wouldn't likely be as much as an issue on the freeway as it is in stop-and-go-traffic?

Thank you for your response

katielady22

I've confirmed that both fans are coming on when the temperature gauge is rising.

Thanks

xwesx

Well, then it is probably time to look into more serious possibilities. The issue could be radiator corrosion that is causing reduced heat exchange or, as you fear, head gaskets, but I am leaning more toward the radiator at this point simply because the head gasket problem tends to cause sudden overheating, often just after having driven highway speeds for prolonged periods. You can perform a compression test and look for black gunk in the radiator overflow bottle. Low compression may indicate a blown gasket, as will combustion byproducts in the bottle. I think there is something called a "leak down" test that can also be performed, but I am unfamiliar with that.

I will be clear though; gasket failure on the late '90s 2.5L engines are not a matter of "if," but "when." I replaced mine at 192,500 miles, which I think was pretty good. I was getting combustion byproducts in the coolant, but was not having any overheating problems. I certainly will not hold it against the car for needing some repair work at that mileage.