2003 Outback LL Bean H6
Here's what happened.
6 Months ago: Car was overheating when starting from a stop (after car was warmed up)
Temp gauge would rise slightly when starting off from a stop and then drop back to normal. It would also do the same when going up long hills on the highway, rise slightly at the bottom of the hill and then immediately drop back to normal temp for the remained of the hill.
I had a new Subaru thermostat installed, the cooling system of course drained, topped up and burped (With Subaru coolant and conditioner) and car worked great for the next two months.
Then I took the car for a 15 hour road trip. I was driving about 75 – 80 Miles/hour on the highway. It was 90 % highway driving, when I was about 1 hr away from my destination I had to go from the highway down into the city, and when I started sitting in traffic temp gauge started to rise, and wouldn’t go back down until I started moving again. It was 100 Degrees outside and probably the hottest day of the summer. I managed to keep the car moving until I got to my destination so the temp stayed down. When I arrived I noticed some coolant had spilled out the overflow tank. So I assume it was bubbling, but did not see. The Next day (It was also a much cooler day) I then transferred all the coolant from the overflow tank back into the radiator. The car worked fine for the 15 hour drive home, although it was much cooler outside and I took it easy on the way home.
When I got home I took the car to my Subaru guy (Master Certified Subaru Tech who works at a dealership here). I had him do a complete check over.
He did a pressure test on the coolant system and found three leaks. One small leak in bottom of radiator, one small leak in a metal fitted coolant house that goes around the side of the engine, and one around the coolant temp sensor.
He replaced the radiator, hose and coolant temp sensor. He also put new clamps on all hoses
After replacing the above, he did a pressure test on the cooling system and it was no longer dropping pressure overnight.
He also did a compression test and leak down test and found no other issues.
He took the car for a good drive (although not on the highway) and it acted fine.
I picked the car up and made the drive home and was also driving about 75-80 MPH on the highway for about a 1 hour drive home. When I pulled off the highway and down into traffic heat gauge started to rise again, also AT Temp light was flashing for a bit. Gauge was going up and down. Coolant was bubbling a bit out of the overflow tank. I immediately shut the car off and had it towed on a flatbed back to my Subaru Tech.
When my tech got the car back he did another compression and leak down test, and couldn’t find anything. After doing a vacuum test he discovered a leak in what he called an internal coolant hose, he said there were 3 of those hoses and so he replaced all 3.
After he completed the work the vacuum test passed as well an additional compression and leak down test again passed.
This time my tech took the car for a long hard drive on the highway after completing the work. When he got back to his shop the car was not overheating but there was bubbling in the bottom of the coolant overflow tank, and some misfires on the cylinders on the drivers (LH) side.
He immediately did a chemical test on the coolant after the drive and it turned from Blue to Yellow, (I guess it normally changes to green with HG failure?)
He also checked the fuel pump housing (I think this is what he called it) for cracks and it was fine.
At this point the head gasket seemed to be the only thing left. So I purchased head gasket kit, a ton of other gaskets and also a new water pump, as I figured might as well replaced the pump when he’s in there.
He just got everything apart, and the old head gaskets (The ones he removed) look fine and have no breaks, he has sent the LH head to a machine shop to check for cracking.
Assuming it’s not cracked, is there anything else I can have him look for?
Edited by dbullen, 27 September 2010 - 10:08 AM.