Suspect water pump

phunk

what temperature do you consider to be overheating, and what temps are you reaching?

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Z_ealot

If i let it sit with the ac on idling for long enough the temps reach upwards of 240 is the highest I've let it get which is almost 3/4 of the way up the temperature gauge inside the car

phunk

will it ever reach 240 under normal conditions or is that just the highest you can get it to go worst case scenario?

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Z_ealot

If i let it keep going with the ac on and idling it will eventually hit the red zone of the temperature gauge in the car, but under normal driving conditions with and without the ac on it usually stays within the 190 to 214 range...as soon as i hit a hill though it climbs pretty quickly up to about 221 where it seems to stop...not sure if it will go higher as i dont have a really long incline to test it on and the 221 temperature was seen on a pretty short hill climb.

phunk

Without a water pump it would overheat very rapidly even while cruising at speed. I cannot imagine a VQ water pump going "weak" due to its steel impeller design. But who knows.

Sounds like an airflow issue though since it seems to act up the most at idle when there is none naturally.

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Z_ealot

Cools itself off fine without the ac on, will consistently keep the temps between 203 and 214

Z_ealot

Ok, so took the temps at the inlet and outlet of the radiator.....both are within about 2 to 3 degrees of each other after everything has been warmed up for about half hour, inlet temp 212 and outlet temp of 210 is what the average seemed to be. Interesting to note however, when the thermostat first opened up inlet temps were around 170 and outlet temps were around 90

Z_ealot

Ok so redid the temperature readings since i forgot to do a sweep of the radiator temps.....inlet and outlet seemed to stabilize at about 203 at both ends and doing a sweep of the radiator revealed a consistent reading of 205. One other thing, when the fans kicked on the temperature reading of the radiator dropped all the way down to 115, but no change in inlet and outlet temperatures

Jhill

Hmm I'm trying to think if this is normal or not. It's been a little while since I've had an oddball cooling car but I'm thinking this doesn't sound right like the flow in the radiator is restricted but then you say the outlet is same as inlet which is good. Maybe your just picking up the cooler air blowing across the radiator. If only happening with ac on and your temps are all fairly close so flow doesn't sound like the issue I'm leaning towards a possible fan speed issue with ac on. I have not really looked at the cooling fan diagram so maybe I'll do that later but it's not uncommon to have different fan speeds and the ac should put it on most likely put it on a faster setting.

Z_ealot

Shouldnt the outlet temperature be lower? Im no cooling system expert, but at least that's the way it works on my honda, inlet temperature high, outlet temperature low

Z_ealot

i'd also like to take the time to note that the fan control module is a brand new unit as the previous original one that was in there died a few months back

Jhill

It will be cooler but not by some outrageous number, more like 5-10 degrees from what I've normally seen. Otherwise it signifies there is restriction/blockage in the radiator causing a slow flow and spending more time cooling etc.

And just an afterthought, highly unlikely but have you checked the ECT to verify it is actually reading accurately?

Z_ealot

Yes checked the ect, it is a brand new unit but thought I'd verify it's functionality before i installed it, it's resistance falls right in line with what the service manual specs specify at all temperatures. Also radiator is basically a brand new unit and flow tested it before installation, also passed testing but just to be sure it was clean i flushed it before installation and did a thorough cleaning of the outer surfaces.

Z_ealot

Ok so i took some users suggestions on here when it came to the question of whether the fans were functioning correctly or not, which leads me to my next question as i havent been able to find an answer to it anywhere. Is it normal for the fans to be making an electrical type buzzing noise when they are on, i notice that when ac is off and the fan comes on it does not make this noise, but with ac on i get a constant electrical buzzing sound coming from the fans although I have heard of ac compressors making this noise also if anyone can tell which one it is. just had the ac serviced a few weeks ago when the radiator was swapped.

edit: checked ac compressor and ac line pressure. compressor wasn't location of noise and ac line pressure is within spec.

Z_ealot

buzzing starts at about the 2:30 mark