Hi all, I have a 2008 RX 400H, with 145k miles on it. I had a crack in my radiator for over a year, no overheating and no leaking of fluid. I decided to get the radiator replaced when I noticed a small amount of fluid in the garage only a few times and thought I should fix the problem before it can get worse. Problem is ,ever since I had the radiator replaced the car drives terrible when the a/c is on. I took the car back twice because it was making a noise when the air was on under the hood and the air was blowing cool, not cold AND there is like a propeller noise when the air is on. It also shakes as if it will stall but only when the a/c is on. The mechanic said the noise was the hybrid system connecting to the condenser and that he saw nothing wrong. They only changed the radiator and now all of these problems, in a car that I have had for 8 years, bought it with 45k miles and NO PROBLEMS in all of this time until now! Any ideas on what the issue could be?? The mechanic told me the radiator has nothing to do with the air conditioning unit so I’m lost at what to do. Thanks in advance

 

I would go to another mechanic. If you can do a side by side comparison with another RX you may find plastic piece that is missing or out of shape that helps direct the air.
Was the air bled out of the coolant?

Maybe a visit to Lexus can help solve the problem. They offer diagnostic service for about $120.

Salim

 

I’m not sure if the air was bled out. But the mechanic I plan on taking it to doesn’t charge for diagnostic service so I hope he can figure out what’s going on. If the radiator and the a/c are not connected I have no clue what could be causing this.

 

I am still learning the hybrid, but in regular vehicles the engine gets additional load when the A/C is running. The additional energy consumed ends up heating the engine up and to dispel the additional heat a second fan turns on.

Noise is due to mechanical vibration which creates air compressional wave (sound) and the air flow over the radiator also cause noise due to turbulence.

The coolant level lo causes gurgling sound.

I hope your mechanic will narrow down the source and find you a fix.

Salim