Automotive Air Conditioning Information Forum

On average, one increases the operating temperature 10 to 15 degrees when running the A/C. Have to have the radiator cooling system check? Also posting pressure readings of the a/c system may help determine what is going on.

I have seen the AC make a vehicle overheat. Make sure there is not a plastic bag sucked up between the condenser and radiator. make sure the cooling system fans are working to specs. Make sure you're not using an aftermarket radiator or condenser that is a POS. Also make sure AC is not overcharged. Make sure that there is airflow going thru the radiator and not going round it.

What year and model vehicle?

A half full radiator is a very bad plan. Get the cooling system full. Make sure you have the proper coolant ratio - NEVER more than 50% coolant.

Does this vehicle use the heater core as part of the bypass system? Bypass flow can be very important on some systems. Is there a heater control valve?

Intercoolers can raise the air temperature quite a bit. We see decreased A/C performance here in the desert when the air temp hits 130+ in traffic.

With that tiny radiator and lots of boost I would expect it to run a little hot. I hope there is a catch can on it to keep it full...



Your intercooler mounting may be recirculating some air as well. It all depends on where the high pressure area is on that setup. Once you raise the ambient air temp with the intercooler, then add the heat from the A/C condenser - that poor radiator is sucking up 140F+ air

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Half full radiator is not helping ANYTHING.

Is that 70% water & 30% coolant?

Several people here know a lot about heat transfer & heat exchangers. None of them are likely to wade through another forum, so you will probably have to answer some questions here.

When you add the heat rejected by the condenser to the air stream, your radiator is not capable of keeping up. There are really only two things that cause that:

1) Not enough radiator capacity

2) Not enough air flow.

When you bypassed the heater did you maintain the flow loop for the heat circuit?

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How do you know it's the a/c system? When you can't even post the pressure readings!

Does the vehicle operate normally, without the a/c running?

Buy some thermocouples - they are cheap.

Put one on each stage of the heat exchanger stack in free air - Ambient / Intercooler Discharge / Condenser Discharge / Radiator Discharge

Find the heat gain for each stage.

A/C condensers can reject as much as 50k btu/h - that is a lot of heat.

If your heater core had water flow 100% of the time OEM, then you need to maintain that flow in the circuit. If you cap or plug those lines you lose important coolant flow.

Stock versions of that car with A/C do not overheat. So the problem is with something YOU modified. Like the undersized radiator. Here is YOUR pic of the OEM unit:



Your words:

I've personally hand built and re- engineered
Much of this car.

Perhaps you should look at getting a refund on that engineering degree.

Wow, so not a West Point grad eh?

bohica2xo wrote:Wow, so not a West Point grad eh?

Looks like near twice to cooling capacity in the OEM version! But hey it must be the A/C.