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S-Class (W222) 2014-2020

Low Temp Heat Exchanger

Old Jan 21, 2023 | 09:47 AM
  #1  
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Low Temp Heat Exchanger

Took my car to the dealer to look at a few things. They said that when they pulled the off the undercover under the engine they found pink coolant all over the place. Checked the lines and fittings and said none were leaking so they want to replace the low temperature heat exchanger. They checked and said that this is NOT covered by CPO warranty. They said they pressure tested the system for 45 min and it held pressure so they think the leak is coming from the low temp heat exchanger.

Any thoughts on how big of an issue this is and if it should or should not be covered under CPO? I wasn't having any issues with the car at all. I am considering not doing anything and taking it to an independent to look at this an get a second opinion.

Any help would be appreciated.

Thanks

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Old Jan 21, 2023 | 10:17 AM
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Originally Posted by benz1983
I am considering not doing anything and taking it to an independent to look at this an get a second opinion.
Do this.
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Old Jan 21, 2023 | 10:20 AM
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Thanks. What does the low temp heat exchanger even do? I cant really find any info on it.
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Old Jan 21, 2023 | 12:50 PM
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The low temp circuit cools intake air coming out of the turbochargers. There's a device called an intercooler where the heated & compressed air gives up its heat to coolant traveling in the low temp system. It sits in the "V" of the engine, right beneath the small reservoir for the low temp system.
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Old Jan 21, 2023 | 01:27 PM
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Originally Posted by benz1983
They checked and said that this is NOT covered by CPO warranty.
Did the dealer give you any CPO documentation that shows it isn't covered? It seems like any system such as that should be covered under the warranty.
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Old Jan 21, 2023 | 02:03 PM
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Originally Posted by as.thompson
Did the dealer give you any CPO documentation that shows it isn't covered? It seems like any system such as that should be covered under the warranty.
not yet. They told me earlier this morning and I asked for it. Seems very unusual for this not to be covered.
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Old Jan 21, 2023 | 03:06 PM
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Originally Posted by benz1983
Thanks. What does the low temp heat exchanger even do? I cant really find any info on it.
May be referencing low temperature radiator.





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Old Jan 21, 2023 | 03:12 PM
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Originally Posted by konigstiger
May be referencing low temperature radiator.



Thank you for this. I think this is exactly what they are referencing. Still weird it isnt covered under CPO
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Old Jan 21, 2023 | 03:29 PM
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If you have not already done so discuss this with the service manager it is a necessary part of the cooling system.
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Old Jan 21, 2023 | 05:58 PM
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Originally Posted by benz1983
not yet. They told me earlier this morning and I asked for it. Seems very unusual for this not to be covered.
VERY unusual since it is part of the power train.
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Old Jan 22, 2023 | 12:30 AM
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As discussed above this should be covered by CPO, but honestly they are also likely wrong.
The low temperature circuit is about 1L, any leak means the system would be very dry.
I would suggest going to another dealer, definetly don't pay for a new radiator yet.
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Old Jan 22, 2023 | 09:51 AM
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Originally Posted by VII
As discussed above this should be covered by CPO, but honestly they are also likely wrong.
The low temperature circuit is about 1L, any leak means the system would be very dry.
I would suggest going to another dealer, definetly don't pay for a new radiator yet.
Thanks. I plan to do this.

For what's its worth I tried to upload a video of what the tech said is the issue. Sounds like a bit of guesswork on his part. Maybe that is why they are saying this isnt covered?

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Old Jan 22, 2023 | 10:23 AM
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If it is a radiator that is leaking out around the aluminum fins then most dealers will say it is not covered because this is typically the result of a rock or debris hitting the radiator at speed and causing the damage. Ironically if it is bad enough your insurance would cover this as a collision depending on your coverage.
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Old Jan 22, 2023 | 02:39 PM
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Soooo the point of the video is to play show and tell about your car. Where is all this coolant that was all over the bottom of the engine and in the plastic under the engine? Did the tech wash it all away (prior to show and tell) to better figure out where it is coming from? Where the point of the video is to show you how awful things are you’d think this would be in the video. Perhaps the tech needs help with cinematography.

If it is the heat exchanger that failed and it is due to a rock hitting it (I would not be surprised) you are out a comprehensive deductible getting it fixed; though you may get into fisticuffs with insurance as they think it should be replaced with used or (crap) aftermarket parts (assuming such an animal is available in the aftermarket).
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Old Jan 22, 2023 | 02:48 PM
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The AC Condesenser is in front of the low temp radiator so unlikely they can blame a rock.

Most likely leak is from main circuit, normal procedure would be to clean up and do a road test.
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Old Jan 22, 2023 | 03:07 PM
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Before replacing parts, replace coolant inclusive of bleeding system see if anything develops. See attachments.

Attached Files
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Old Jan 22, 2023 | 03:11 PM
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Originally Posted by VII
The AC Condesenser is in front of the low temp radiator so unlikely they can blame a rock.

Most likely leak is from main circuit, normal procedure would be to clean up and do a road test.

Great plan Mercedes.... put a heating element in front of the heat exchanger for charge cooling! This is a factor for me living where I see temps up to 120 in the summer. She pulls boost with higher charge temperature.

Rocks manage to get to everything but the radiator behind all the layers of the stack. It happens. Radiators also like to leak from a seam in the moulded plastic to feed the intake a diet of coolant. That was fun.
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Old Jan 22, 2023 | 04:01 PM
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Originally Posted by konigstiger
Before replacing parts, replace coolant inclusive of bleeding system see if anything develops. See attachments.
thank you. Sounds like first step is to ask the dealer to refill the cooling systems and road test it
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Old Jan 23, 2023 | 11:20 AM
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As an update, the dealer said they were "Suprised" that the low temp circuit cooler wasn't covered under CPO.

I asked for documentation of what was submitted and the response from Mercedes and the service manager at the dealer said all they do is put the part number into the Mercedes system and Mercedes tells them whether or not it is covered. Does this sound right?

They encouraged me to submit a goodwill assistance claim to MBAUSA, which I did. Do people have any luck with doing this?

They quoted me $1900 to replace the low temp radiator.
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Old Jan 23, 2023 | 11:49 AM
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Yes and no, one deciding ‘arguable’ factor is if you have your vehicle regularly maintained by MB dealer.
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Old Jan 23, 2023 | 11:51 AM
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Originally Posted by konigstiger
Yes and no, one deciding ‘arguable’ factor is if you have your vehicle regularly maintained by MB dealer.
Thanks. yes, the car has been maintained at the dealer for all service since I bought it CPO from a dealer 2 years ago.
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