My 1999 C230 was driven through a lot of water recently. The MAF was replaced as well as the the cabin filter. Apparently, water went through the air ducts and was expelled into the interior of the car. The fan would not operate. The dealer changed the MAF, changed the oil, cabin filter, etc. but didn't check the AC. Took the car back and they recharged it. Went to 41 degrees but a week later no AC. I'm taking it back in on Monday.

I need some help because the insurance company doesn't want to pay to fix the AC. It worked perfectly until this water incident. Did the water allow pressure to build up in the system and cause a refrigerant leak? Any theories? Thanks.

most likely refrigerant leak. check all a/c hoses if you see an refrigerant oil build up somewhere within the lines. if you find one thats the culprit
good luck

That's what it was. There was a leak in the condensor. Unfortunately, the dealer could not say that the leak was caused by driving it though the water. It seems to me that somehow the water caused pressure to build up in the system and that caused the leak. If anyone has any theories how driving through high water could cause a refrigerant leak I would appreciate it. It would save me $1,300.

The condenser is in front of the radiator. Any debris going through the grille of the car will hit the condenser first. Where was the leak? Was it in a location consistent with debris impacting the condenser?

Brett

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1997 S600 sedan

Good point. However, the dealer told me the leak was in the rear of the condensor, the side facing the radiator.

the condenser gets very hot when the AC is on because the heat in the cabin is transferred to the refrigerant and the refrigerant dissipates the heat in the condenser.
The physical structure of the condenser is very vulnerable, you have so many corners and weldings and weak corners of that sort where the little tubes going across connect to the main column that brings in the pressurized refrigerant.
Metals show the most expansion and contraction due to temperature changes, the condenser is made of metal (aluminum i think???) so when it's hot it is in the expanded state.
What I think happened is that the water which was cold hit the condenser when it was hot and the "heat shock" caused it to crack due to "rapid" and "uneven" contraction of the different parts I say uneven because water did not cool down the condenser in a uniform manner but rather a random pattern of water splashing on the condenser. The water caused a heat shock to the condenser and the non uniform cooling caused some parts to contract while some parts are still hot in their expanded state. Like a tooth, eating ice cream after a hot cup of tea is not such a good idea and causes a crack in your tooth.
see if they'll buy this from you. try to get a hold of the old condenser and hope that there is a crack no matter how small where it looks like some one pulled on both sides of the crack to sort of rip apart the condenser. (it doesn't have to exactly look like that but that's how I'm picturing it in my head) I would expect the leak to be in a corner, corners are the weakest spots.

Sounds like the water may have put pressure on trash that was already between the radiator and the condenser...May have only been a matter of time before you sprung a leak anyways...

Thanks, Koskesh. You may have just saved me $1,300. Thermal shock caused the condenser to crack. The water was about 3 feet high so there was an immediate contact between the hot condenser and the cold water. Your explanation certainly makes more sense than saying that it was just a freak coincidence. Anyone know how hot a condenser normally gets when it is extremely hot outside?

If you drove through 3 feet of water you're lucky that's all that was damaged...in fact it's not very smart to drive through any standing water that you can't or don't know the depth of. Cars have been known to be swept away or submerged trapping their occupants.

I'm in the process of replacing the engine on a nice late model Nissan Sentra that hit a puddle nowhere near 3 feet deep and it sucked water up through the intake and hydrolocked one cylinder and broke a connecting rod which went through the block. The guy had no insurance and couldn't afford to fix it so the car went from being worth $13,000 to $1,000 in just a few seconds.

Lesson to us all...when there's standing water of uknown depth, simply wait and drive later...the risk is too great to the car and its occupants.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

So......what your saying is : Turn your a/c off before it rains ?



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"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Thermal shock is the word i was looking for. I'm not exactly sure how hot it gets but i know it gets hot enough to burn your hand if you touch it.

230 F.


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[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Unfortunately for my wife who was driving the car at the time in Arlington, Virginia when they had all of that rain, the road was dark and she says she couldn't see where she was going. She almost got swept away. The water was up to the windshield and she kept driving and a few seconds later was through it but the car just about stopped running after that.

Didn't I read somewhere that it is not recommended to hose off your radiator/condenser area after driving the car because of leaks? If someone could point me to those series of posts I might be able to convince the insurance company. Makes sense -- going from 230 degrees to 55 degrees instantaeously sounds like it would cause damage to the condenser or radiator.

Thanks for your input.

I'm from Iowa but I lived in Arlington, VA last year. Very nice area, I remember driving east on high way 50 or Arlington Rd i think is the other name and watching the washington monument. I lived in Clarendon. I never saw heavy rain like that though. Well I hope that they cover the AC for you. Water that deep could have seriously ruined your engine.

'com on guys....don't tell me that rain water at 40 degrees destroys a/c condensers !....there's no foundation for this theory, otherwise everyone would have this problem every time it rained hard.

The possibility is : The heavy weight/pressure of the deep water the vehicle entered exerted enough pressure to bend and crack the condenser fitting on the hose connection.

Try dragging your hand through the water to experience water pressure at 20 knots next time your on the water.


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__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."