Changing thermostat in 1998 Forester

To change the thermostat you first need to remove the undercover. Remove 4X 12mm bolts and two plastic push clips (one on each side). The thermostat is under the engine on the drivers side. Remove the coolant hose and remove the two 10mm? bolts and drop the stat. Remember to replace the o-ring gasket and align the jiggle pin toward the front of the car. Top up coolant and away you go. I hope it is not a head gasket problem. Ed

Only familiar with my 95 2.2 but it is probably the same on your 98. The thermostat housing is located where the bottom radiator hose joins up with the engine block. Prepare to crawl under the front of the car. The 2 bolts are either a 10 or 12 mm. An extension helps> Entire job shouldn't take more than 15 minutes. Also need a screwdriver for the hose clamp.

Thanks all - Looks like a fairly easy replacement, if I don't freeze to the parking lot!

John

Forgot to mention/comment about air pockets. You'll probably create one changing the thermostat. Keep checking the coolant level on the way home as it will probably go down on you.

In that weather, I suspect either some type of coolant loss or the t'stat - BUT, since it overheated while stationary, you should confirm the radiator fan comes on when the temp gets to normal.

Carl

Thanks again all for the info. It's 11 degrees below right now so I've delayed the trip to fix the Subie until tomorrow. What happened was my wife was on the interstate in below freezing conditions when her temp gauge redlined - she pulled into a truck stop and found anti freeze all over the engine compartment. She let the vehicle cool off, added more antifreeze and drove a few miles and the same thing happened. She went back to the truck stop and ran the engine while another guy looked it over and neither could see any leaking hoses and the fan belt was intact. As the engine rapidly warmed up coolant would come out of the overfill hose (which was lose). When I got there the temp was dropping rapidly so I did a quick look over and decided to come back the next day with a thermostat, which by my diagnosis seems the most likely problem. I think that at these cold outside temperatures, the fan would have little effect. If you all have any other ideas I'm sure appreciative of the input. As it stands now I'm heading out tomorrow with a thick blanket to lay on, tools, hose clamps, anti-freeze and a replacement thermostat.

John

"Carl 1 Lucky Texan" wrote in message news:iJtlf.28111$ snipped-for-privacy@newssvr21.news.prodigy.com...

A couple things to consider. Only use OEM tstat. When I replaced mine sub'd a Beck Arnley I picked up locally and not dealer in town. The cost was a high as factory tstat but found out the hard way the tstat opening was only 50% of factory model which kept the temp on the edge of having the fan on most of the time.

Second, as has been mentioned, BIG need to purge the air out of the system. Factory procedure is to run engine at high idle for 15-20 mins until bubbles stop in the overflow tank. What I did was not quite fill the radiator completely full and left the cap off. Ran until tstat opened and coolant made initial drop. Then topped of the radiator, put the cap on ran the engine until cooling fans cycled twice. By then I didn't note any bubbles in the overflow tank. When the engine cooled off there was little draw from the overflow tank.

Mickey

Now I'm confused. I thought sure I replaced the thermostat on my '99 Outback with the 2.5l engine. And it was behind the water pump which was behind the timing belt which was behind the timing belt covers. Not a 15 minute job at all.

Yes, it is somewhat behind the timing belt but, the stat is under the water pump.

Probably need to make sure the temp selector is on heat. Some folks have luck doing the procedure on an incline - nose up. Do check the rad and o'flow tank for a couple drive cycles afterwards.

Carl

Yikes! Is this the location of the tstat on a 1998 Forester 2.5 l ? Quite a few folks responded and told me it was easily accessible from under the engine where the lower radiator hose connects. Which is it ?????

John

After you remove the undercover you will see the thermostat housing with the two cover bolts facing toward the ground.

I did that a time or two before giving it some thought. Water exits the engine between fwd and rear cyl. When on an incline, the front cyls are higher than the water exit point. Good chance air could be trapped at the front of the engine.

When I had to do this the last time I was on the first leg of a 4k mi trip. When I finally returned home, there sill was no need to add any water to the overflow tank. No more elevated position for me when the cooling system needs changing.

Mickey