A few weeks ago I asked about oil in the radiator and overflow. People gave me some good advice and now Im back for more.

 

I had a friend pressure test the system to 15 lbs. The system held the pressuer without any problems. Ive been doing alot of dirt road driving over the last 5 months so we decided that the gunk in the radiator was dirt getting into the system. Over the last few weeks Ive made several long trips in the car and it held up fine. Temp gague never went above half. There have been no signs of water in the oil or being burnt.

 

Recently Ive been noticing that the overflow has been staying full of water and the radiator is empty. Car still runs just as cool as ever.

If there is a head gasket problem shouldnt the pressure test have shown a drop in pressure? what else could be causing the fluid to collect in the overflow. Stuck thermostat, or a bad radiator cap? Is there anything else that im not thinking of.

 

Lastly, am I fooling myself and I just need to replace the headgasket. What test can I run to know for sure that the head gasket is bad.

 

sorry its so long

-Dave

Dave, year , model, 1.8L, 2.2L, 2.5L ???

haha sorry

 

98 Forester S 2.5L automatic

 

one more thing to add, I noticed the other day that the top Rad hose was warm, not hot. And the lower hose was cool to the touch. ive always known that to be a sign of a stuck thermostat.

try the cheap fix first.. get a new radiator cap. Water not being pulle back in is usually the cap. ..especially since everything else checks out ok.

 

 

nipper

Yes, Dave, you are fooling yourself. The goop in the coolant is from combustion gasses seeping through the head gaskets into the coolant. The full reservoir is because you no longer have a vacuum to suck the coolant back into the system. The pressure test will not reveal the bad HGs because they only leak one way, from cylinder to coolant under the extreme pressure of the compression stroke. Mechanics who have not been exposed to the 2.5 DOHC have a hard time diagnosing the problem because it is not a typical head gasket failure. The head gaskets don't "blow", they just let air seep into the coolant. Thus the HGs appear intact, and they are, they just let little bits of combustion gas through on each compression stroke. But not enough to detect on a compression test. Still, with all those compression strokes, they add up to air pockets in your cooling system.

 

Go to Skip's page and read about all the people who have been through the same thing as you, with the same engine as yours. It has happened thousands of times.

 

http://home.comcast.net/~skipnospam/

 

The overheating is often the least symptom of this failure. There is often still enough coolant in the system to keep the car from overheating except under severe conditions. There is no definitive test. The goop, the overfull reservoir, the occasional overheating, are all classic symptoms of failed HGs in your engine. Really. Your head gaskets are bad.

 

Say hello to Maine for me. Ex-resident of Turner, Gorham, and Peak's island.

 

Tom

DO the hydrocarbon test, it is the definitive answer, as there should be no hydrocarbons present in the cooling system at all.

 

 

 

nipper

Thank you everyone

 

So I am convinced that it is a head gasket. The car is now parked untill it will be repaired. I cant risk blowing the motor.

Tom, thanks for the straight out answer, thats the best explanation of the problem that I have seen. Everyone having doubts should read that. Maine is doing well, nice ans sunny today and promising to be a good weekend.

 

Thanks again

-Dave

Dave, Nipper is right that the hydrocarbon test is definitive, but the hydrocarbons are already visible in the coolant in the form of the sludge, so you know they are there. I've also heard of false negatives with the test, but I don't know that first hand.

Read some of Skip's guest book. At least you won't feel so alone.

 

Good luck,

 

Tom