I'm definitely not an expert on mercedes mechanics and hoping someone can help. Took my 2013 c63 amg coupe in for the a3 service today. 45k miles on the car and purchased it used from carmax last October. As they started the oil change, the mechanic said there is a slow leak caused by aluminum bolts that has been leaking for years. Basically saying they can pull the engine and reseal but it would take 40 man hours and not guaranteed to fix the issue. Other option is replace the motor costing $50k. Out of manufacturer warranty but have extended warranty from car max.

The risk is, they pull the motor and find the root cause is not covered under extended warranty and I'm stuck with the bill for pulling the motor and putting it back.

other risk is extended warranty covers it but they use a refurbished motor from junkyard instead of new motor from mercedes. Worried that returb motor will bring the value of the car down.

so first question, is this a known issue with the c63?

second question, should I rely on extended warranty to cover resealing the motor and hope it solves the issue?

apologies if there are existing threads on this. Used search but didn't see anything but it could be that I am just not familiar with the terminology.

appreciate any help here. Love this car but the thought of a used motor that doesn't match the original numbers will devalue the car and I'm not comfortable with a used junkyard motor.

 

How big a leak is it? Maybe it has sealed itself as you did not say if there is oil in the pan under the engine.
They can put a dye in the oil that glows under UV light so you could find out if it is still leaking and how serious it is if it is leaking still.
If it is a small leak and you can live with it I would leave it and just be diligent about checking the oil.

 

So the leak is at the bottom of the motor? when they say aluminum bolts, what are they referring to?

 

Need more information, where is the leak ending? Can you see it from only low down or high up the engine? Side, front, back of engine.

See my thread below

https://mbworld.org/forums/c63-amg-w...any-ideas.html

 

Someone else had a leak caused by a through hole for the motor mount. Apparently a flaw in the upper pan casting.

It was right side, bottom bolt closest to the trans I believe.

 

https://mbworld.org/forums/c63-amg-w...ine-block.html

 

The description of a slow leak caused by a bolt and spending 40 hours to reseal the engine with no guarantee says to me that they have no idea what is going on - if they know where the leak is then they know what it takes to fix it.

Can you get anymore information on exactly what is leaking? For 40 hours or 50 grand, trade that in on another one or sell it back to carmax and go buy another one, way cheaper to deal with!

 

I had this leak on my 2011 with 62k miles. They told me engine would have to come out and be resealed. most likely the upper oil pan. had them inject the dye and it turns out they have to replace the bolts and the upper oil pan entirely. was covered under extended warranty (now with power train only). takes a very long time though due to the labor and the upper oil pan is usually not stocked and has to come from Germany.

 

Yes, it's the upper oil pan. Basically the seal is crap and it's leaking. Had the dealership put dye in to see how much it's leaking since I haven't been low on oil or had issues in the year that I've had the car. If it's a bad leak then I may have them reseal through extended warranty. Or maybe time for an s63 upgrade

 

if they reseal it make sure to have them inspect the oil pan. Mine was bad enough that it couldn't be reused