campbell

My E350 wagon started getting a "hot" oil smell coming from the engine bay.. no leaks on the under tray but I found a puddle of oil right behind the throttle body, it was difficult to see any source - has anyone had this issue? thanks!

CaliBenzDriver

It is standard for this engine new or old to have quarts of steaming engine oil swamped in the intake plenum. It gives these great cars a distinct smell so some model now feature automatic cabin perfume dispensers.

The engine oil issues are produced by vaporizing oil over the superheated pistons.

Mercedes added a sort of catch-can to the throttle body to conveniently capture oil leaking back out. You'll want to get this emptied out during annual service.
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What type of engine oil are you using?
Try to use an "MB Approved" oil with more stable viscosity, replaced at 5kMi will help.
Do not use 10kMi intervals !!!

campbell

Wow, thank you - had no idea it was set up like that. I have always changed oil every 5k using Mobil 1 0-40. I will try to find the catch can next time under the hood. Thanks again

pierrejoliat

Also if you chose to use 5W40 or 10W40 this would happen less as the higher viscosities tend to vaporize slower, unless you are in the great white north with temps below zero F.

Apexlate

The crankcase valve may need to be replaced.
https://www.fcpeuro.com/products/mer...eal-2720100631
This usually drips oil onto the cat causing an oil smell in the cabin.

campbell

Thanks for your comments.. I will confirm where the oil is. We are between Chicago and Florida in the winter.. never know how the weather is going to be!!