Yup, I remember MA state inspections. I was driving a hard plated pool Cressida (not my regular company car)and got pulled over in downtown Boston for not having an inspection sticker on the car. Since the car was registered to the company, the officer was kind enough to issue the ticket to the company instead of me.
As far as the Legacy, my advice is to dump it unless Subaru has made some kind of improvement in the design to prevent future reoccurrences.
I have been struggling since August with very similar problems with a '98 Legacy Outback, 2.5L engine. The problem appeared after I replaced a broken heater hose. To make a very long story short, the cooling system now seems incapable of handling the transition from high load, high coolant flow conditions (e.g. highway driving) to light load, low flow (e.g. suddenly slowing down in traffic). The temperature gauge will spike from the normal 9 o'clock position to offscale hot in about 30 seconds. If you see this happening and immediately place the car in neutral and rev the engine to about
4,000RPM, the system will usually recover, with the temperature gauge dropping back to below 9 o'clock within 30 seconds. If you don't catch it fast enough, the coolant will boil over. The car has no problem cooling during extended driving in stop and go traffic on hot summer days, only the transitions bother it. It appears the thermostat can't open fast enough to deal with the changing load- but no thermostat is going to respond on a timescale of seconds. The cooling system was pressure tested by a local garage, who found no problem. Drilling a few 1/8" bypass holes in the thermostat flange to allow some coolant flow even when the thermostat is closed seems to have provided a solution to the problem, but with temperatures often going to -20C here the engine doesn't warm up properly. (It's worth noting that in a post a few years back the owner of a used Legacy of this vintage discovered the thermostat had been removed, and found overheating problems when a new thermostat was installed). I have filled the cooling system as slowly and carefully as I can, including extended running at idle with the radiator cap off to "burp" the system. The burping seems to go on for a long, long time, suggesting it is very difficult to get air out of the system. If anyone has a solution to this strange problem, I'd really appreciate hearing it. In the meantime I'm living with the bypassed thermostat.Garry
This sounds very much like what happened when I changed the thermostat in my '94 Acclaim 3.0L. I found that the old thermostat had a considerably bigger orifice; I believe the smaller orifice on the new 'stat is restricting flow somewhat.
It certainly sounds like you're doing a lot of the right things.
Um, are you certain the 'burping' is done with the heat set on 'max' and have you changed the radiator cap?
Can't really think of anything else - maybe someone will have some more suggestions.
Carl
I had a very similar problem once on my 98 outback. It ended up being the thermostat - I changed it once because the car wouldn't heat up and then it began overheating. It turned out to be a faulty thermostat so i got an OEM one from the subaru garage and it solved my problems. Although, you've already replaced your thermostat I'd recommend trying a second one - I was about ready to replace my water pump and had already had my radiator checked for blockages before I changed the thermostat a second time. According to the radiator shop where I had my radiator checked, faulty thermostats are common - the guy told me a story of having to buy four once before getting one that worked.
I tried a new radiator cap- no improvement. I've been "burping" parked on a steep incline with the rad higher than the engine and the heat on max, although I think coolant always circulates in the heater core no matter what the heater setting.
The new thermostat (second source) and the Subaru original showed identical behaviour when heated in water, both opening nicely at the temperature stamped on the thermostat. I suspect both are working as designed. The Subaru thermostat has a slightly larger aperture.
The car is not consuming coolant so I think the head gasket is OK.
Even after repeated "burping" sessions there are still bubbles appearing, so I suspect it is very difficult to bleed the air from the system.
Thanks,
Garry
Look under Subaru thermostat operation I might be able to help
There must be something wrong with the heater hose Read subaru thermostat operation Michael
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.