When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I join this forum to possibly learn avoid taking to a Mercedes dealer to do things myself since I’m not close to a dealer and the wait time is long. I hope this group doesn’t mind I just want to make sure my wife & son have reliable transportation. I have coil #5 with I replaced but light and coil still pops up… my scanner won’t reset it… first thing I noticed before tackling the job after I pulled the cover off I notice some oil. I have a video so maybe someone has seen the same issue before. Been a great car so far. under 150k miles. I’ve put 40k on it this year. I’ve just never owned nor worked on one before. Also if anyone has any recommendations as far as to try to clear light without scanner that’ll be great. Battery was discounted whike I did the work. Figured I’d try that before I do the spark plug. I do here a ticking noise time to time… Thanks in advance. I love this car. Just hardly gets driven and not trying to buy another. If I did I would buy the same exact thing.
You have a fair amount of oil leaking near the cam magnets. This is common, and can come from 2 or 3 causes:
- leaking front cylinder head covers. This does not cause a check engine light. It is fixable by the dealer or indy.
- leaking cam magnet seals. Same as above, fixable and does not cause CEL.
- leaking cam magnet connectors or cam position sensors. These can cause CEL if the leaking is extensive or has existing for some time. The solution is to replace the sensors and magnets, and possibly the engine harness if the leaking is extensive.
Clean away the oil with small targeted squirts of brake fluid and shop (paper) towels. Then you can find the source.
You have a fair amount of oil leaking near the cam magnets. This is common, and can come from 2 or 3 causes:
- leaking front cylinder head covers. This does not cause a check engine light. It is fixable by the dealer or indy.
- leaking cam magnet seals. Same as above, fixable and does not cause CEL.
- leaking cam magnet connectors or cam position sensors. These can cause CEL if the leaking is extensive or has existing for some time. The solution is to replace the sensors and magnets, and possibly the engine harness if the leaking is extensive.
Clean away the oil with small targeted squirts of brake fluid and shop (paper) towels. Then you can find the source.
Or take the car to an indy shop for a diagnosis.
How hard is this to tackle myself? I could only image what a dealer would charge
Mostly not hard. Resealing the front cylinder head covers is tricky.
1. Clean away all oil. 100% of it. Then keep an eye out to see where it comes from. Magnet replace and reseal is straightforward. New magnets and new screws. Very low tightening torque because the screws are single use and made of aluminum. Resealing the cylinder head covers is trickier and I suggest you have the dealer do it. It will be a few hundred dollars.
2. Open as many connectors as you can to check for oil:
- cam magnets x 4, these are mostly accessible on the ML350 with M276 3.5L
- cam sensors x 4, only one of these is accessible without taking more parts off. A second sensor is accessible by removing the air filter housing. The remaining 2 require intake manifold or vacuum tube removal.
- ECU connector, this is accessible
06-03-2022, 11:29 PM
