A couple of days ago, late one evening when our son got home he complained about a problem with his car. It was dark, had a funny smell but not one I could identify. Next morning the coolant was low. Dumped some it and it ran right out at the lower hose next to the radiator. Got a new hose (assumed it was a bad hose). Got the car up a bit and the hose at the radiator was just very, very loose. Just pulled it off. Had the new hose so went ahead and replaced it. Dumped coolant it, ran it, seemed fine. Next morning the coolant was low, assumed problems getting the system filled. So added, ran it and got a check engine light. No code reader so , cleared the code. Checked and topped off the coolant and son headed off to work. Check engine light came on in a few minutes. About five miles from home he pulled over, getting hot.
Get in back home, the temp was okay for a bit and then a rapid rise to about 3/4. Let it cool. Cleared the light. Added coolant...but added less like the system is filling up. No sign of any leaks. Oil looks fine. Engine seems to run okay.
So played with it some more. Starts fine when cold or hot. When cold the car idles fine and then in about four or five minutes slows way down, then speeds up to 1400-1500 rpm idle. A little pressure on the throttle and the rpm swings up and down, very steady, rhythmic swing of about 300 ripm. More throttle seems to run fine and smooth, no swinging of up and down of rpm. Gets up to about 3/4 on the gauge and stays there. When you shut down the temp starts to lower rapidly. Still no leaks, oil looks fine.
So I am wondering thermostat? Water pump? Until this the temp was rock solid, didn't move once at operating temp. The cooling system looks pretty clean (can't see the radiator of course).
Aside from getting a code reader (not sure that is the problem causing the cooling issues) next step?? Just checked it again. Coolant is very low, sucked the overflow very low so I am back to thinking it might be a head gasket. Overheated and then warped and headgasket. Ohhh Fudge! Still not sure why the temp goes up...
i dont think that a small overheat would have warped the heads so easily, i say this because i have an 02 wrx and overheated the hell out of it while on the salt flats and had absolutely no issues after it cooled down, and have had no issues with cooling since then bout 3000 miles ago. could be that the coolant is seeping in thru the turbo and getting blown out the exhaust, or burnt up. about how long untill the fluid is low and is the car just sitting or is it being driven?