fastback174

Changing oil on 2014 '63, noticed the intercooler reservoir between the
turbos on top was empty.

Reading around, heard has a separate radiator up front that often gets
small leaks. This might be the case.

Anyone run into this? Car runs great, temps good, the other coolant reservoir fine,
but obviously that tank's there for a reason.

Will say in 8 years I've owned it, have never topped off, so maybe
it's time. Or maybe its a rock chip in the secondary radiator and slow leak

Regardless, I'll fill 'er up to level and see what happens.


Any thoughts appreciated...

fastback174

Update: As I was parked in front of the dealership to schedule appointment, puddle of coolant formed under the car.
Good place to lose the coolant. Turns out the low pressure hose to the intercooler radiator is CLOSE to the turbo pipe,
and it had burned a hole through. Hence, small leak turned catastrophic. $500 intercooler line ain't cheap, but better
than $2500+ intercooler radiator if it was punctured.

Lessons learned:
1) Periodically check the intercooler overflow reservoir under the plastic cowl. There's no fluid level sensor on it.
Only warning will be poor engine performance and a check engine light. Suppose if run long enough, worst
case scenario turbos overheat and fail expensively.
2) Doing some research for low intercooler level causes, many AMG owners (GT particularly) have been getting debris
large enough through front scoops to puncture intercooler radiator which is in front of main radiator. Consider
putting a finer screen behind the factory one (but potentially less airflow to radiators). MB actually has
provided a retrofit plastic screen to put on the intercooler radiator for the GT.

ColonelKlink

Fastback174, what should be the coolant level in the intercooler reservoir (IR)? There is a post in the middle of the tank in your photo. My tank has similar inside post with coolant below that level. Should coolant be at that level? or some other mark? Should I add directly to IR? Or should I add to main reservoir and see if system will self-fill? (main system coolant is stable.)

fastback174

To the top of the "cross" post in the tank is full.

fastback174

Add to the intercooler reservoir; separate system from main radiator.

Karandeep Singh

Hi,
I just bought a CLS63 and came home from a 3 hour drive home. Next morning i seen stain on my driveway the size of baseball. Pretty Sure it’s coolant/antifreeze. Anyone familiar with a small leak from the front passengers side ?

Also, when i purchased the car I saw that the center reservoir under the engine cover was half way full.
i had driven 3 hours and i topped it off just because. Now that I’m home it’s back at where it was.

Any ideas, just curious before i take the car in.
Cars driving fine no over heating or anything

TooManyIDs

Per above, did you check the hoses?

Karandeep Singh

Honestly, haven't messed around a lot with it since it's raining a lot here. The bottom part of the top reservoir has coolant in it.

I believe it also probably is a hose but let's see.

MBenzEnthusiast

What engine code came up?

Karandeep Singh

I took the car to an Indy shop near me specializing in AMG's and Benz. They said three coolant lines were leaking and were replaced. It's been a day, need to see the level the reservoir is at when I get home.

fastback174

Have had my M157 for 10 years, no issues except the OP and hose replacement. This may be one of the parts that
needs to be checked before purchasing used....other than that, pretty bullet-proof engine.

Karandeep Singh

Update: Coolant level remains where it should and no more leaks.