Oil cooler leak? - Why/how?

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May 4, 2022 | 03:27 AM
  #1  
Hi guys

New to this forum. I work daily in the car industry and am therefore daily surrounded by car people. But thought I would check in with you guys and hear the opinion of other AMG owners as well.

Long story short, I have a C63 Performance Sedan from October 2012 with 64,000 km / 39,800 miles. I’ve had the car since 2020, when I bought it with 55,000 km / 34,200 miles. As you can probably see, I don’t drive the car very much as I have 2 other cars.

About a month ago I took the car out of 1 year of storage. Car fired up without any hesitations or problems. Of course it had that famous ticking for the first couple of minutes these cars usually has when they have been parked for a while. I gave the new fresh 5W40 Liqui Moly oil as well as MoS2 additive. It also got new transmission oil. Thought I might do that as well now that the car was already up on the lift.

The other day I noticed a good amount of oil in front of the right tire. I drove the car into the lift to see where it was coming from. Looks like my oil cooler has decided to quit. I applied a lot of brake cleaner and wiped the area with compressed air. The leak reappeared very quickly. See photos.

1) Can you guys somehow confirm that it’s the oil cooler? I'm just about to order a new one (not cheap) and just do not want to throw money at something that is not the problem.
2) I am curious by nature. Why is my oil cooler "already" faulty? What's the cause of that leak?

I baby my cars, rarely drive them hard (this one do get some hard pulls maybe 4-6 times a month because it's a "race engine"), oil change every time they go to storage and come out of the storage etc .. My 2 other cars are American and the main reason I have this car is because of the legendary M156 engine and the sound the car has. It's exceptional

I look forward to hearing from you and your input.







Reply 0
May 4, 2022 | 05:37 PM
  #2  
If you have to change your cooler, it may be a good idea to think about getting an enlarged one. See following thread: https://mbworld.org/forums/c63-amg-w...option-13.html
Reply 1
May 5, 2022 | 01:15 PM
  #3  
I'd look at it more from the fact that your car is a decade old rather than its total use as a potential source of the issue as to "why", entropy has a two-fold effect in that regard to vehicles.

I'd wipe away all of the fluid and then with the engine running see if you can deduce a leak location.

Also, in particular with this car you should probably drive it more often than you are and not be afraid of using the rev limiter to 7.

The engine was purpose built for racing when they made it, the car around it was purpose built for luxury and handling of the engine, I'd recommend at least driving it every two weeks and having some fun while you do it to try and "keep it fresh" if you will.

You bought a retired racehorse that can carry four people essentially to try and be analogous.

After you finish with that since the car sat for so long you should probably just change the fluids in general
Reply 0
May 6, 2022 | 04:10 AM
  #4  
Why,, no corrosion protection!
How,, All metals corode.
Reply 0
May 7, 2022 | 06:39 PM
  #5  
Quote: If you have to change your cooler, it may be a good idea to think about getting an enlarged one. See following thread: https://mbworld.org/forums/c63-amg-w...option-13.html
Thanks for your reply. I was actually considering that option, but I do not drive my car on the track at all and it also seems that those parts are a little hard to get hold of.
Reply 0
May 7, 2022 | 06:50 PM
  #6  
Quote: I'd look at it more from the fact that your car is a decade old rather than its total use as a potential source of the issue as to "why", entropy has a two-fold effect in that regard to vehicles.

I'd wipe away all of the fluid and then with the engine running see if you can deduce a leak location.

Also, in particular with this car you should probably drive it more often than you are and not be afraid of using the rev limiter to 7.

The engine was purpose built for racing when they made it, the car around it was purpose built for luxury and handling of the engine, I'd recommend at least driving it every two weeks and having some fun while you do it to try and "keep it fresh" if you will.

You bought a retired racehorse that can carry four people essentially to try and be analogous.

After you finish with that since the car sat for so long you should probably just change the fluids in general
Thank you for taking the time to write my post. Yup, of course the car is 10 years old, agree.
I cleaned the whole area and the leak reappeared relatively quickly in the bottom of the cooler. The hoses seemed dry. Ordered a new cooler, but unfortunately it's on backorder. Will know during next week when I can expect it.

And you're right. I should drive the car a little harder more often. And also generally just drive the car somewhat more often. When I had the car on the lift the other day, I saw that the right rear shock absorber had a leak. My best bet is because the car has not been driving for a long time. That's a different story, but it's a quick fix.

And sure, I changed all the other fluids in the car as well
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