Hello forum,

My car has been running much cooler since I swapped out the fan control module. I now hear the fans go on (but not on full/high) when the air is on low, with a gust coming up from the fan enclosure when I place my arm just above the front of the engine (the litmus test described by Thermo). The fans do come on high/full when the engine heats up. In the summer the temperatures go up to 100 degrees or more in Los Angeles. On the freeways she runs about 185; in normal stop and go traffic about 195-205 all day long - that is with the air con on. But there is one exception -

Under a load, on about a 5-10 degree incline, in stop and go traffic (0-30mph), the temp shoots up to 215, 220 within about a mile or two. Maybe not so high a temp with the air con off, but still... this seems a bit of an extreme a temp change, to me, and it feels like the temp would go even higher if the hill went on longer. The temp goes back down once I'm on the downhill side of the hill (~208) but it takes a several miles for it to get back to 200 or less.

(Because of my past heating issues, I monitor the temperature closely with a ODBII device and Torque Pro.)

Does this sound normal? Doesn't seem normal, to me. Coming from a motorsports background I'm very sensitive to heating issues. I've replaced the thermostat and will replace the water pump next week. No leaks anywhere and fresh coolant in the radiator.

Anyone care to chime in?

Thank you forum members!

 

Jag4, I know this may sound funny, but with the car cold, remove the overflow bottle cap and then reinstall. When you removed the cap, did you hear the system sucking in air? What it is sounding to me is that you have a slight vacuum on the coolant system (it, you put on the cap with the coolant system at temp) and what is happening is that angle reduces the pressure on the water pump suction and it is causing the water pump to cavitate a little bit. Give that a try and see what you find. Otherwise, I would call it normal.

 

Thanks, Thermo. I did that and swapped out the water pump for a AC Delco Pro. It was 120 degrees today on the surface street, stop and go engine temps were below 205. Temps still go up to 215+ on the long fwy uphill but it seems to cool a bit quicker. If that sounds normal to you then ok.

The only thing I still notice is that, with the air con on, under some load, the fans don't always kick on high when the car heats up 210+... but if I stop for gas, lets say, and then restart the car, the fan speed kicks on high and then seems to stay high even when the car cools down to below 205. (I'd need to confirm the above, though. I'd image the fan behavior should be predictable, based on heat dempratures, alone?)

I'll continue to monitor the temp and see if I can repeate and isolate the bevavior. But if occasionally creeping up to higher temps (215+), under a load is fine, then I'm fine with it. Thanks again!

 

Jag4, As long as things are staying in the 215 range, then you are good. It is when you start seeing 230ish that you need to start worrying. This car uses a pressurized system, so, it can push the temps a little higher then you would think.