Just wondering if anyone can assist me with diagnosing a potential issue with my cooling system. Symptoms: 1) After 15 minutes from cold, the temp guage shows almost on red (hot) 2) Randomly, when idle or driving into a headwind, the guage will reduce back to half... then may rise up to hot again when caught in more traffic. 3) The radiator hoses aren't extremely hot or "squishy" even after an hour... which indicates the water is not boiling (correct?) 4) The radiator is suspiciously cool. After an hour it didn't burn skin off when I touched the top of it... in fact, it was only mildly hot-ish. Now, I had a mate with the exact same problem and it turned out to be a faulty tempreture sensor, but I think the radiator is not as hot as it should be, and the fact that it warms up to that position, and some times reduces temp on the fuage when in ideal cooling conditions. I am not sure where the problem(s) lie, is it the radiator, radiator cap not sealing correctly, thermostat issue, coolant temp sensor, E.M. temp sensor, etc etc. BTW: this was working fine one day, then from the next day on I have had this issue... no idea why or what caused it. Any assistance appreicated.
does your thermo fan come on once the temp gets over half way as it should? and if it does is it going at full speed, it has two modes- a low speed and high speed. when you say you touched the radiator and it didnt burn you, was this the radiator cap, or the actual radiator. the radiator itself doesnt get heaps hot, after all it has heat disipating qualities - the nature of a radiator. the cap on the other hand is different, that should be quite hot to touch after the car reaches operating temp. im thinking two things at the moment (untill those question i asked have been answer anyway), either a blocked radiator or as you said a faulty thermostat.
yeh word of advise. change ur thermostat cause it may be stuck shut and flush ur radiater a.s.a.p. this happened to me. or go to a wreckers and pik up a good radiator cheap. thats what i did and no problems since. and even if it doesnt fix it, its was still worth doing but its most likely them two things.
Might be worthwhile checking the operation of the water pump also. It could just be a faulty gauge, the temp gauge sender is only an $8 replacement, so I would probably try that first, along with a new a thermostat, and go from there.... as they are the two cheapest options.
Thanks for the info... might have to go shopping. To answer "sircruisealotVS", yes - I touched the radiator cap, and didn't check the fan... oops. Further note: A further complicating issue with this... I have had a trans upgrade and am running a trans oil cooler for it. Unfortunately the only spot for this was directly in front of the radiator. Still plenty of airflow around it... but its not ideal cooling. That aside, this "problem" appeared approx 8 months after this oil cooler was installed... so probably not the issue.
if your radiator cap is not really hot after driving the car then there is definately a problem with coolant flow....whether thats due to the thermostat or a blocked core on the radiator i couldnt say.
Might also be worth trying a new radiator cap, another cheap option, but maybe the current one isn't up to the job. Coolant under pressure raises the boiling point... Also make sure you are running the correct mix of 50% concentrate coolant, and 50% water in the cooling system.
