Follow the crankcase ventilation path. Air entering the crankcase will keep that area cleaner and the air out area will be sludged up, this is typical for any engine especially a V configuration.

Yeah you are right, the passenger side is ported to manifold vacuum.

OTOH Really funny ones are the toyota 2AZ where some mechanics break/cut the ventilation baffle under the oil fill cap (youtube videos of this exist too) - and wonder why its sludging up in the lower end. Without the baffle guide air goes in from one side of the valve cover, makes a U turn and out the back of it.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Thanks for all the helpful advice. I found a bit more about this car earlier today. My friend has owned the car for 4-5 years and never changed the oil, air filters or coolant. He just added to what was already in there when needed. In his mind that is an oil change lol.

An "All coolant compatible" type of antifreeze has been used to top off what I have to assume was originally the MB light yellow stuff. The coolant tank has what looks like that yellow/green color which conventional coolants are.

For motor oil, name a brand and/or viscosity...and I'd bet it has been used for topping off. There was a partially used "Trop Arctic" 10w40 quart bottle and an unopened "SuperTech" 5w20? bottle in the trunk.

So in the next few days, I'm thinking an oil/filter change, air filter, coolant flush, and brake fluid change is in order. Strangely enough the transmission fluid looks completely fine and doesn't smell off.

I should have checked when the car was here...but does the E320 use the same oil filter cap tool as my S550?

Thanks again...

__________________
Lance Allison
Lance@LanceAllison.com

Current:
11 MB S550 4Matic, 55k miles, Designo Black/Black
14 Ford F150 XLT Lariat Crew, 73k miles, 5.0
Coyote V8 4x4. Black/tan.
09 GMC Envoy Denali, 5.3 V8, 4x4 SWB. 38k miles,
Jewel Red/Med Gray.

Gone:
87 MB 300SDL, 320k miles, Astral Silver/Blue.
98 VW Jetta TDI, 488k miles, Classic Green/Gray.
85 Olds 98 Brougham FWD, 4.3 DIESEL V6, 80k
miles, 3x Gray.

MBCA Member, Chicago Region

Should be the same 74mm wrench.

If it’s been performing acceptably all this time, is he going to spend on proper maintenance now and from now on?

Sixto
98 E320s sedan and wagon
02 C320 wagon

Sixto - I am certain he will not continue with a maintenance schedule. He's already killed an OM617 in an 85 300SD and has an 83 240D 616 w slushbox that has neck-snapping shifts and won't start under 50 degrees.

The E320 in this thread was bought new by our county sheriff. It was a nice, clean car. Now (in addition to lack of due care) the entire car has BAD tin worm disease. You can see light through the wheel arches. I shudder to think what the spring perches look like.

__________________
Lance Allison
Lance@LanceAllison.com

Current:
11 MB S550 4Matic, 55k miles, Designo Black/Black
14 Ford F150 XLT Lariat Crew, 73k miles, 5.0
Coyote V8 4x4. Black/tan.
09 GMC Envoy Denali, 5.3 V8, 4x4 SWB. 38k miles,
Jewel Red/Med Gray.

Gone:
87 MB 300SDL, 320k miles, Astral Silver/Blue.
98 VW Jetta TDI, 488k miles, Classic Green/Gray.
85 Olds 98 Brougham FWD, 4.3 DIESEL V6, 80k
miles, 3x Gray.

MBCA Member, Chicago Region

This is another "normal" W210 feature. I bought my E320 new as well, and it had visible rust patches just two years later. By the time it departed ten years later, it was thoroughly ventilated.

"Ventilated". Great way to describe the rust. Love it!

__________________
Lance Allison
Lance@LanceAllison.com

Current:
11 MB S550 4Matic, 55k miles, Designo Black/Black
14 Ford F150 XLT Lariat Crew, 73k miles, 5.0
Coyote V8 4x4. Black/tan.
09 GMC Envoy Denali, 5.3 V8, 4x4 SWB. 38k miles,
Jewel Red/Med Gray.

Gone:
87 MB 300SDL, 320k miles, Astral Silver/Blue.
98 VW Jetta TDI, 488k miles, Classic Green/Gray.
85 Olds 98 Brougham FWD, 4.3 DIESEL V6, 80k
miles, 3x Gray.

MBCA Member, Chicago Region

Lance, in addition to the oil, coolant and brake fluid changes I encourage you to change the transmission fluid/filter and the spark plugs. Check the Owner's Manual for the proper spark plugs and transmission fluid, or call your local MB dealer. I own a 1998 E320 (purchased new) and changed the transmission fluid for the first time at 85,000 miles and the spark plugs for the first time at 108,000 miles … both were in acceptable condition. From now on I intend to change the transmission fluid every 60,000 miles, same for the spark plugs. As mentioned previously, I use Mobil 1 0W40 in that engine and change every 7,500 miles. I am sure you are aware the new MB coolant is blue, or you can opt for Zerex G-05 Coolant which is amber … 50/50 mix. This engine does have an oil level dipstick. As I recall MB eliminated dipsticks as a cost reduction on the newer vintage engines that have an electronic dash readout for engine oil level.

__________________
Fred Hoelzle

Good advice on the plugs and transmission...and I mentioned that to the owner when we discussed the oil mess the other day. He is "going to wait until we confirm there isn't some other engine problem" which basically means it will never get done. It was challenging to convince him to use a quality oil of the proper viscosity and get the right coolant in it.

Bought a couple 5-quart jug cases of Mobil 1 0w40 Euro formula when a parts/racing store had a going out of business sale and that is what is in the car now. Along with the standard gray and white box MB-branded filter cartridge.

I've used G05 coolant across the board for years and always have it available, so that is what I used after a few cleaner->drain->water->drain cycles.

I can say with 100% certainty this particular car had a small rubber/plastic plug where the oil dipstick would normally be. Passenger side toward the front of the engine. I have 2 service dipsticks - the shorter one (red handle) worked fine to check the engine oil level, but I didn't leave it in. The verdict is still out on whether or not the oil level can be checked from the instrument cluster after changing the oil. I should be able to see the car again Monday or Tuesday.

__________________
Lance Allison
Lance@LanceAllison.com

Current:
11 MB S550 4Matic, 55k miles, Designo Black/Black
14 Ford F150 XLT Lariat Crew, 73k miles, 5.0
Coyote V8 4x4. Black/tan.
09 GMC Envoy Denali, 5.3 V8, 4x4 SWB. 38k miles,
Jewel Red/Med Gray.

Gone:
87 MB 300SDL, 320k miles, Astral Silver/Blue.
98 VW Jetta TDI, 488k miles, Classic Green/Gray.
85 Olds 98 Brougham FWD, 4.3 DIESEL V6, 80k
miles, 3x Gray.

MBCA Member, Chicago Region

I’ve never had a problem., never had a sludge problem either

__________________
1993 e300
1995 e320
1994 e320
2006 s500 4matic
2004 Jeep wj overland
2001 Ducati 748
2004 Honda shadow aero

Four + decades of building / repairing engines says otherwise.

Good oil changed regularly won't cause sludge to begin with. For cars with a carburetor, 3 / 4 K on regular oil is about the limit, using synthetic here is a waste because poor fuel control contaminates the oil. I run synthetic in non turbo fuel injected cars to 8 / 10 K due to tighter fuel control keeping oil cleaner.

Mercedes specified synthetic for this motor. The engine has a tendency to build sludge in start/stop service, as you've seen in this thread.

To whom is directed towards?

Lance, for that engine without a dipstick the Owner's Manual should provide a step-by-step procedure for getting an oil level indication on the instrument panel.

__________________
Fred Hoelzle

Leave the key in on without starting the engine. In a few seconds the display will ask if you want to check oil level. The display will change before you remember which button is yes Really, MB, why not just display the oil level instead of asking?

Sixto
98 E320s sedan and wagon
02 C320 wagon