My wife was driving her 2018 RDX, FWD, and ended up in a fender bender where the front bumper of her car was damaged. She said she saw steam flow out of the passenger side of the engine compartment. My first thought was the radiator, but I checked the coolant level and it was fine, plus there was no coolant on the ground. I drove the car home and the temp gauge and coolant level are fine, but when turning the AC to the low setting on the way home it did not seem all that cold, but I don't drive her car and am not that familiar with the AC unit. Does anyone have any idea what type of gas or steam may have escaped out of the passenger side of the engine compartment, could it have been from the AC system or from something else? Any thoughts would be appreciated. TIA

 

Did you check the wiper fluid reservoir?

 

Thanks, I will do that this morning. She said it made a hissing noise which make me think whatever it was it was under pressure. I'm also not sure if was steam or something else.

 

The wiper fluid wouldn't be under any pressure to release like that, unless the tank burst and got onto something hot like the exhaust manifold and vaporized....but that's kind of a long shot. The high and low pressure AC lines are indeed on the passenger side of the engine, but I'm wondering how they would have burst in a fender bender. Plus that gas shouldn't be visible when it's released. Do you happen to have any pics of the engine bay?

 

It's definitely not the wiper fluid resevoir. What did see was a small radiator-looking component on the driver's side of the radiator that looks like it has been very mildly leaking. Not sure if that's an oil cooler or connected to the AC system.

 

I completely agree with your thoughts regarding the visibility of anything being released from the AC system. I don't have photos of the engine bay, but checking it this morning everything looks fine. I'm puzzled though, that both my wife and the other driver saw what they described as steam. Thanks for your thoughts.

 

If it's the small radiator in the bottom right corner (when you're facing it from the front), you're probably referring to the transmission cooler. If it's leaking, you'll see red fluid coming out of it (assuming it has OEM fluid in it). If you think it's leaking, I'd check your trans fluid level just to be safe.

 

Thanks, will do. It's a very mild leak, if it's leaking at all, and was serviced about 30k miles ago. I still don't think that's the culprit on the passenger side.

 

As a follow-up to what was replaced and may have caused the steam, the transmission cooler and AC condenser were replaced. My guess is that condensate or some sort of fluid from the cracked condenser on the passenger side resulted in visible steam/vapor being released.