1stmbenz

Hello Everyone

I have a 1993 400E. I noticed over the weekend if I have my A/C running while I'm driving, I sometimes see like steam come from from the lower part of the engine compartment. This is been happening for a little over a month. I'm unable to see the cause of source of the problem. My A/C continues to be cold. I'm not seeing any visible signs of a leak. Forum, what are some likely causes?

Jer

How hot is the coolant? You might have a leak that manifests itself at high temps. The leaking coolant then boils when released from the high pressure cooling system. If the A/C is still running (and running well) then a refrigerant leak would not be likely. Never hurts to check, though.

bamberger_1

Another cause could be that the condensate from the evaporator of the A/C is somehow finding its way to the muffler or any other hot part of the engine causing the steam

Kestas

Next time the car is stopped, see if you can waft some of the vapors to your nose. If you smell coolant, you need to find the leak. If no coolant smell, then it's your a/c drain and there's no need to worry. Check your coolant level, and see if the problem goes away on a cooler day where you're not using the a/c.

1stmbenz

I haven't noticed any loss in coolant. The smells like more than just water. Again, this only happens when the A/C is running and the car is being driven for a good period of time.