rc11

It's hard to tell which pumps failed while driving, but a diagnosis from the dealership after the fact informed me that three coolant pumps + the switchover valve failed (I was originally told 2 pumps failed, but they told me that 3 pumps failed). The car was in the shop to get the auxiliary radiator replaced (it was leaking). A half an hour after picking the car up for that repair is when my trans oil temps started skyrocketing. So, maybe the pumps had started to burn out when the auxiliary cooler went down.

In your opinion, do you think there was some meaningful damage done to the trans from the short-term, albeit high temps?

W213e63s

Hard to say, but I doubt it. Depending on how many miles you have on your car, you might want to change the transmission fluid - it's recommended for 50k miles but I'm changing mine early. I was going to do it at 30,000 miles since I track the car - I have ~27k miles now and will change before my next track day.

Since my aux heat exchanger was busted, and given the pump failures that others have had, I wasn't convinced that bleeding the cooling system was going to solve my problem despite having a new aux heat exchanger. So, I ordered both aux pumps that are on that circuit and took them to the track with me this weekend. And as I suspected, my temps started to rise during the first session on Saturday but not in the red. Took my car to the speed shop on site and once we got it on the lift, we could hear that the right pump was working but not the left one. Swapped it out and I was back on track. Never saw anything close to red transmission temps the rest of the weekend,

rc11

Thanks for the quick reply. I have less than 500 miles on the car (lol). I was in a similar situation to yours--the auxiliary cooler went out, they replaced just the cooler and bled using xentry. I'm hoping that the pumps going out right after I picked the car up from the auxiliary cooler repair was just some collateral damage that was overlooked from the cooler leaking and not indicative of a larger systemic issue.

Mike Bradshaw

Just bought a 2018 C63S Coupe and noticed the transmission temp was hitting 235 F under subdued driving so I parked it and called my dealer. Told me it was normal but thankfully I found this thread and got some good advice. Found a rock hit-leak on the lower radiator which was causing the temp spike. Will be replaced - OUCH - but should be no damage to the transmission per the dealer since I parked it so quick. My question is has anyone found a way to add a shield to these radiators to prevent what looks like a common occurrence in these cars? Appreciate any feedback on this. BR.

Mike Bradshaw

In a follow-up to my thread below I believe I found a solution to the open grill issue. Found a ZUNsports distributor- (British manufacturer of a myriad of protective mesh grill covers for a lot of different cars) - 5 o'clock motorsports- Dan at 571-434-8333 who ordered a set of black stainless steel grill covers - left ,right lower center openings -that go on over the existing grill openings by way of a clever toggle bolt system. He is also asking Zunsports if they can develop a grill /radiator cover for the upper opening as well. Cost was $338 delivered to me in Houston TX. Sure beats the $1200 I paid yesterday to my MB dealer to repair a rock hit to my low temp transmission radiator . FYI there was a class action lawsuit filed over this issue as well January of this year. Makes some interesting reading. BR. Mike

hhyndoy

What is the part number for the one circled?

EDIT:
LEFT: 000-500-55-00-80RIGHT: 000-500-38-00-80 (circled)