Engine Heat with AC On Options

[HardHead93]

It got a little warm today in southern New Mexico so today was the first day I drove the 3sgte swapped Celica in stop and go traffic with the AC on. Normally without the AC on, the engine temps bounce between 189 and 199 degrees F. When I turned the AC on it climbed to 209 degrees in the course of 5 minutes before I turned the AC off. Once I turned the AC off the temp quickly dropped back into the normal range in about another 2-3 minutes. I am reading the temps off an aftermarket water temp gauge with the sensor on the upper radiator hose. Below is a picture of the type of gauge I am using. It is a Glowshift MaxTow water temp gauge.


When that gauge reads 215 degrees the stock dummy temp gauge in the car starts moving towards the H. I am running an Ebay 2-row radiator with aftermarket fans and I have a FMIC. Should I keep the aftermarket fans or go back to a stock radiator with stock fans? Also, the Ebay radiator is pretty dirty from constantly taking it in and out of the car during the build process, could that be the culprit? Is there something else I should check on that may be causing the engine temps to climb with he AC on? Below is a picture of the 2 different radiators.


Is there really an advantage to running a 2 row radiator with a 3sgte?

This post has been edited by HardHead93: Mar 17, 2017 - 7:33 PM

[Bitter]

Sounds like the system pressure is going high due to lack of cooling, is it missing fins? My 7G Celica condenser was missing most if the fins in the lower 1/3 of it, replacing with a good new Denso unit restored my AC to blowing ICE cold at all times. An over charged AC system can cycle off due to high pressure as well, under charged will blow extra cold or not work, but at the expense of causing low lubrication to the compressor due to lack of oil flow in the system. Which leads to the least happy possibility, there's debris in the system causing high side pressure to go too high.

But AC is a heat pump. it pumps heat from the cabin to the outside. If the system isn't working correctly because of a charge level issue it won't be moving the heat. It sounds like the AC is working properly and overloading the cooling ability of the radiator OR the FMIC is introducing too much heat into the condenser and radiator for them to all work properly. It's a shame you can't move the FMIC forward into the lower mouth and divert the air passing through it downward and out before it hits the radiator. That would still be blocking too much airflow. I think the GT4 bumper may be the only fix, that or figuring out some kind of dual SMIC setup like some VW's use.