96 OBW 2.5

 

A few weeks ago, (which was a couple weeks after getting a new water pump and timing belt-coolant flush) the temp gauge would rise to about 3/4 of the way to hot as i got on the highway, then would settle back down after a few minutes. this happened for a few days as i commuted to work (never happened on the way home from work). I was told by some of the members on this board that it could be bubbles in the coolant that would likely work themselves out. The temp gauge doesn't rise anymore, but it seems to take a little bit longer to warm up. Also, when I first turn the car on, the idle shoots up to 1500, sometimes even close to 2000 rpm. . I am wondering if it's possible that I have vapor lock? can the symptoms just not be present during daily driving? I'm planning to take a trip over the cascade mtn range pretty soon, and I'm afraid of having an overheating nightmare, or the dreaded HG failure. Any ideas? Should I try to correct for vapor lock even if it's not an issue?

Seems like you COULD have 2-3 different problems.

 

I would still go ahead and try 'burping' the coolant system. Try to find a procedure by user - setright -.

 

Perhaps you have a bad thermostat - you didn't mention changing it.

 

Do you have a CEL? If so, a code might point to a problem concerning the idle at start - I suppose a bad temp sensor could be telling the ECU to choke the car. Or some kinda IACV problem.

 

Carl

tstat and gasket were changed with the tbelt. The only cel codes have been cylinder 4 misfire, which was fixed by a new injector. No codes have been thrown for weeks. I think i'll burp the coolant system just because, who knows. The tstat seems to be working fine, and the car will heat up after a few blocks, maybe that's how it's supposed to be and the last tstat was faulty. who knows. Any links to a proper coolant burping technique?

[...]Any links to a proper coolant burping technique?

As Carl (1 Lucky Texan) suggested, here's a link to one possible approach:

http://www.ultimatesubaru.org/forum/showthread.php?t=28193

 

By the way, I assume that by "vapor lock", you're referring to an air pocket in the cooling system. Usually, "vapor lock" refers to a condition where liquid fuel has gotten so hot that it's vaporized (typically in a fuel line, pump, or carb bowl [where it's called percolation] of an older vehicle) before it should; when that happens, the engine can't run. It's not usually a problem on modern fuel-injected systems.

thanks for the clarification OB.

 

Isn't there a way to force out any air pockets without fully draining the system? I seem to remember seeing someone say that adding coolant with the engine running, with the occasional rev would do the trick. Is that not a good method?

thanks for the clarification OB.

 

Isn't there a way to force out any air pockets without fully draining the system? I seem to remember seeing someone say that adding coolant with the engine running, with the occasional rev would do the trick. Is that not a good method?

 

 

Sorry, didn't fully read the link (dummy). Thank you for the help.

No problem, you're welcome. Page 10 of http://www.endwrench.com/current/winter02-03/EngineMaint.pdf has Subaru's recommended approach.