bullitt69

Hi everyone!

I purchased my 2011 facelift C63 AMG with the P30 package about a month ago. The car has 53000 km (33000 miles) on it.

When I had it checked at a local Merc dealership prior to purchase, they told me there was i minor oil leak at an unusual spot which was probably the result of spilt oil.

2 weeks ago I had my strut mount bearings replaced at a different shop and they noticed the leak as well, noting that it was probably leaking from in between the the 2 parts of the crankcase.

I asked them to wash all of oil off to see how quickly the leak would progress.

Anyways yesterday while I was getting my secondary cats straight piped I decided too peek inside again and there was oil.

As you can see it is leaking somewhere from the engine block underside the right exhaust manifold and near the right engine mount.

Does anybody have any clue what it could be and how I can get it properly diagnosed?

Thanks in advance!

Jasonoff

My guess is somewhere in the upper portion of the pan on that side.

bullitt69

I got it checked today. They screwed out the bolt you can easily see in the previous photos which fixes the steel engine mount bracket (holding the engine mount) to the engine block and some oil leaked out of the bolt hole.

The mechanic said that it's very weird that there is oil behind the engine mount bracket.




The part I am referring to as "engine mount bracket" is under numbers 10 and 5. In my case it is number 10 (right side).




I'm planning to replace both engine mounts and to remove the leaking bracket to check what's behind it.

Jasonoff

Because oil is leaking from up higher and seeped it's way in behind the bracket.

Not the pan then. Something up higher.

Phil_T

Currently got a leak in pretty much the same place, its a small slow leak and you can see stains on the undertray. When under the car you can see fresh oil above the pan so it's coming from higher up. Merc couldnt find ot so clearned it all off and told me to come back in 1000 miles. Said if they cant find it they would have to pull engine at $140 x 10 hours!

https://mbworld.org/forums/c63-amg-w204/654633-small-oil-leak-any-ideas.html

Jasonoff

His is leaking a lot further forward.

AwdthisC63

Nothing is behind motor mount bracket which seems to believe leak is higher than the bracket. Passenger side front engine cover leaks there is a oil thermostat which tends to leak. Seal gives out But that would be in front of engine cover and front passenger side of block. Driver side the oil cooler lines also leak which looks like it's from the pan. Clean real good and apply trace powder to area of leak

bullitt69

Thank you for the advice! My leak is exactly on the passenger side of the engine but closer to the transmission and not to the front of the engine

bullitt69

I hope you'll be able to solve the problem without suffering the expenses of pulling the engine!

Phil_T

Mine is same area but other side (RHD) so could still be the same problem and something may be on the other side with yours being LHD. On mine it is also towards the back leaking down onto the bell housing of the gearbox then sitting on the lip of the lower pan.

swatty

The engine mounts are filled with oil, maybe one is leaking ?

Vladds

You beat me to posting this.
In this car, the engine mounts are hydraulic, oil filled and when they fail, they leak oil, that's how you know they failed. Also, only one of the two mounts usually breaks, the one that is stretched.


I saw some people posting that the transmission mount should be replaced at the same time.

bullitt69

I initially thought it could be oil from the engine mounts, but oil can be seen way above the mounts. I see no possible way oil could have gotten there - only if the mounts exploded sending oil everywhere around :-)

chrisridebike8

Oil from the engine mounts is red. and once it leaks like that, the car will rattle your teeth out. That doesn't look like when my motor mount blew out.

Jasonoff

Phil's leak (pink)
valjay's leak (green)

I doubt it's the same source.

Phil - I suggested PCV for you because it's pretty much a direct line of sight from the PCV (arrow in pink pointing to it).

valjay - Wrong side of the engine but it's almost a mirror image. Mount circled in green, leaking from somewhere above that in the direction of the arrow. If you don't have any smoking it could be coming from the front edge of the valve cover.

bullitt69

thank you for visualizing the problem, I'll get it checked according to your advice

AMG6.3

You went through the trouble to have car inspected prior to purchasing and did not address the leak prior to purchase? Do you have a warranty? I would take car back to where ever you bought it from so they can fix it or compensate you.

Goodluck

Phil_T

Thanks I appreciate that, Is it still engine out job to get to that area? A highly regarded tuner has offered to diagnose for $100 and said if it is an engine out job they wont charge close to even what Merc have quoted. The stange thing is since one of the visits to merc recently the car in comfort mode has slammed into 1st gear when setting off on a staight flat road 4 times and now after being in there again last week in comfort it seems like the gearbox is slipping in comfort mainly in 2nd & 3rd gear (worse when going uphill) Its like clutch slip with the revs going up slightly and not engaging on the car (and I know what clutch slip is like as I had an Audi S3 running alot of BHP and went through two Sachs performance clutches with slip issues) gearbox seems very jerky and clunky going back down gears in comfort too.

Jasonoff

Nope, easy enough to check but it is a bit of a pain to change the PCV because it's tight back there. DIY from an E63 but nearly identical to our car. https://mbworld.org/forums/w211-amg/...-m156-e63.html
Is your car tuned? Either way try resetting the adaptations.

http://www.mercedesmedic.com/reset-m...-instructions/

Phil_T

Thanks, will mention PCV to the tuner but like you said that area drops straight down onto the bell housing and top of pan so could well be my problem. Ashame its only got 24k on clock and merc cant look down that area for me. Also after reading the PCV thread you linked how funny I have been hearing a slight whistle noise when inside the car! I thought it was just the air vents that have become noisy.

I did the adaptation after the the gearbox was jumping into 1st in comfort and it stopped, the slipping has got worse after that as it used to do it mainly when cold but now does it all the time. I did the adaptation again today so will see how I get on. Do you guys leave the key in? As it says some cars might need it out but I have always left it in the ignition.

Jasonoff

Leave the key in. Is your car tuned or not?

Highly doubt the trans is slipping.

Phil_T

The sliping has been there about 2 month, car was v5 from new nearly 4 years ago. Something is definitely slipping as you can see it on the dials and hear it from the tone of the engine/exhaust. The gearbox is changing harsh down in comfort and going up through the gears very quickly and it feels like it's slipping in the gears instead of the usual of you not feel it going through the gears in comfort.

Jasonoff

Some people had weird shift issues with V5 that simulates slippage. Have you contacted Jerry? I'm sure he can get you sorted.

Phil_T

Its been fine for nearly 4 years till now which made me think its not a V5 thing so not got in touch with Jerry. I thought it might be a TCU issue? Like you said stage 1 & 2 supercharged over 700bhp are fine on standard gearbox and its only stage 3 the plates and TCU need doing.

604 C63

I think Phil has two separate issues here also. I get the wondering and temptatiin to think there is one given they are simultaneous, and their physical proximity.

Good diagnosing J.....you must have read all the interwebs.