[Subafreak]

We had an Outback at the shop a wile back that was occasionally overheating. The guy brought it in so we could find out why it was overheating. We first changed the T-stat then filled it up with coolant and let it run to make sure it was circulating and the cooling fans where working. We even checked for a blown headgasket with a chemical reactive tester (very easy to use and availible at your local NAPA for like $20)and it said it was OK. Told the customer what we did and that it seemed good to go but he was skeptical and let us keep it for a wile to drive. So we drove it around town a few times and it was fine, so I finally took it home one weekend (about a 30mile trip) and nothing, then on the way back to work on Monday it finally overheated, I pulled over and popped the hood to find that the overflow jug was full to the top but the lower radiator hose and radiator was cool to touch, I took the cap off and added about a gallon of coolant and the temp came back down and I got it to work. We then decided to change the waterpump along with the T-belt and camseals. After we did that we took it down the road again and it did the overheating thing again, pushing all the coolant into the overflow jug. We stuck the leak tester back on it and left it their for a long time, it just barly started to turn the blue liquid to yellow indicating a blown headgasket. So we ended up doing headgaskets on it and it fixed the problem. Turns out that on that motor the head will get a low spot in it around the exaust porst and allow coolant in to the combustion chamber.


Short version: Go get a block tester, just because there is no smoke out the tail pipe dosn't mean the headgaskests not blown, and your rapid gauge action is usually consistent with a blown headgasket. Sorry.