Hey all. I went and got my thermostat replaced to try to treat an overheating problem and it was even a genuine subaru part. My car is still handling funny meaning it heats up very very quickly. I've been pretty dilegent as far as the oil changes go, but have let one or two go over the 3000 mile mark. Is it possible that there is build up in the engine or do you guys think it is merely another component of the cooling system that needs to be fixed?I have to drive my car from san diego to san francisco and don't feel comfortable with the way it is running. I'm taking it to yet another mechanic. The dealer told me nothing was wrong with the car. Any help with the diagnosis would be much obliged. I just want to get my car and me back home safely.

What car do you drive (+ year) and how many miles are on it?
Edit (Found the answer):
I drive a 2004 impreza outback sport with 60 k miles on it.

Regardless of the above info, I highly doubt you have sludge if you've changed your oil every 3K.
I'm no mechanic, but sludge is unlikely with today's oils if changed reasonably.

I drive a 2004 subaru impreza outback with 60k miles on it. Hopefully it's not the engine.

i am a mechanic :lol:

no really, i am.

water pump could have died. probably the case. if that were the case, it'd always over heat, no question. other than that it would be the radiator, which would have somewhat different symptoms. hard to say w/o checking out myself, of course.

What about the old "2.5 w/out subaru conditioner in the radiator" syndrome, i.e. head gasket kaboom. It's a stretch for an '04 w/60K miles, but has this angle been explored? Are there any signs of coolant leaks/missing coolant? +1 for the not sludge opinion. You'd have to drive alot more miles over 3K when a change was due (like, 10,000).

the conditioner was also infamous for clogging!
PS why do you change your oil every 3k??

its def not sludge. when ur car overheats its usually a cooling problem. next time check your coolant levels and then go from there.

you have a blown headgasket buddy...same problem that i'm having right now...sucks!

99.8845% of overheating problems in Subarus are caused by bubbles in your coolant. If you can DIY, read the Coolant FAQ for tips on removing them as they are a pain even for Subaru mechanics. Once you are sure you have no bubbles, then you can look at the advice given above.

ooo, i think i know what your talkin about...is it the old "burping" the system, making sure theres no air pockets?? theres a special way to do this

why do you think it's the head gasket?

Because many of the (older version) 2.5 engines have had this issue. There was a service campaign to get people to put the coolant conditioner in their radiator a few years back because the issue became epidemic. The engine block would develop leaks, letting coolant out or into your oil. Result was engine failure. A 2004 w/ 60K mles should be fine, the reason it was mentioned was so you could check this out. Have you changed the coolant since you owned the car? Have you had this car for all 60K miles? For more info search "coolant conditioner" in NASIOC.