Question On Air Conditioning

[rxdriver]

Are there any downsides to running the air conditioning while parked and idling on an RX330? Would overheating be an issue?

I've always wondered if this causes any issues to either the engine or air conditioning components. I generally don't have the air conditioning running if I'm parked.

Any comments and thoughts are appreciated, thank you.

[KBRX330]

My wife has tested the limits of the RX330 AC system in such a manner and now at 145k miles it still blows cold air. Note: There is a warranty extension on your radiator to 7 years 90k. Ours went bad at 89,500 and was replaced under warranty. The top seam of the radiator fails and you will see the coolant level in the overflow plastic bottle drop to zero. I noticed it because I check it every week along with the oil, tires etc. SO if your RX is running hot better get the radiator pressure tested. Ours never overheated because I caught it in time. FWIW, I run 5w30 Pennzoil Platinum synthetic oil which will take the idling abuse & punishment my wife & daughters hand out on a daily basis.

[RX in NC]

The 2004 RX330 radiator TSB mentioned above applies only to Canadian-built vehicles, not Japanese-built vehicles. If your VIN starts with a 2, your vehicle was built in Canada. If your VIN starts with a J, your vehicle was built in Japan....

[Grumpa72]

In a vehicle with a properly operating radiator, water pump, a/c system, thermostatic fan and its related components I would say that there isn't any damage to your vehicle. Oth, I have never liked the idea of loading up a vehicle by doing this. While I stand by my original statement that I don't think it hurts anything, I just don't think it adds to the longevity of a vehicle. By that, I mean that, given two identical cars, one operated in stop and go traffic with lots of idle time and the other on mostly highways at hhighway speeds, I would put money that the latter one will last longer with fewer maintenance issues.

Gary

[wwest]

Are there any downsides to running the air conditioning while parked and idling on an RX330? Would overheating be an issue?

I've always wondered if this causes any issues to either the engine or air conditioning components. I generally don't have the air conditioning running if I'm parked.

Any comments and thoughts are appreciated, thank you.

In the olden days, days of yore, running the A/C with the engine idling and the car motionless would quickly result in the coolant overheating, beginning to boil, and soon thereafter the engine would stop, SIEZED.

But nowadays, for most modern vehicles, if the coolant begins to approach (not "reach", nor exceed) the level of overheating then the engine/transaxle ECU firmware will simply disable the A/C (as it does with WOT) until the engine water jacket cools back down again.

If you really wish, or need, to run the A/C continuously in this situation you might get away with it using the following procedure.

First, activate the air recirculate mode so the system isn't having to continuously COOL the incoming outside HOT air. Next, turn the system to maximum cooling. In maximum cooling mode the HVAC system's reheat/remix mode is bypassed and not even a small portion of the system airflow will be reheated after being first cooled via first flowing through the evaporator. Now use the manual blower speed control to moderate the cooling level and thereby sustain the cabin comfort level.

To go even a bit farther to improve the system's cooling efficiency I have installed a manual water flow shutoff valve in the engine compartment so I can shut off the hot water flow to the heater core ENTIRELY during the summer months. I also had the dealer set the available C-best options such that when I turn the A/C off via the PB it remains off FOREVER, plus a day, (disabled even in defrost/defog/demist mode) unless I turn it back on.

Once the cooling season is over I turn the A/C OFF and it remains off until the next spring.