2001 E320 Oil Oddities - PeachParts Mercedes-Benz Forum

Lance Allison · #1 02-07-2019, 07:02 PM

One of my friends brought his 100k mile 2001 E320 over and asked if I could check the oil (only has the little stopper in place of a standard stick). Using a service dipstick, I checked it and found it to be slightly low - maybe 1/2 quart. The oil cap was VERY tight requiring channel locks to remove it. All over the underside of the cap and in the area in the valve cover where the oil is poured into looked very bad (see pics). Engine oil smelled normal as did the coolant and trans fluid. Those were also at acceptable levels. The car doesn't overheat

When trying to read the oil level from the instrument cluster, a message saying "MEASURING NOT POSSIBLE" shows up.

Before digging into this, does anyone have an idea of what to look into first? Thanks.

Sugar Bear · #2 02-07-2019, 07:36 PM

Lance, Do you know the history of the car? Constant short trips? Extended oil changes? Type of oil used? Does it reach full operating coolant temp? Does it run hot?

If it is just dirty/contaminated then several short interval changes (500 then 1,000 then 2,000 miles) following longer trips at full temp may clean it up.

Be cautious with oil additives/cleaners, they can break sludge loose too fast and block oil passages.

Good luck and please post the progress.

engatwork · #3 02-07-2019, 07:55 PM

Need to trouble shoot the oil level sensor in the bottom of the oil pan.

sixto · #4 02-07-2019, 09:31 PM

I don’t think I’ve seen a case that bad but mayonnaise on an M112 oil filler cap is oddly normal. Some say the riser design causes that. If there’s no oil in the coolant, let it be. You’ll not hear many stories of M112s blowing head gaskets even when overheated.

IIRC the oil level check needs about 5min after engine shutoff to register. You’d think it wouldn’t offer you to check it won’t check.

Replacing the oil level sensor requires dropping the lower pan. When they fail they throw errors. It’s probably functional if there are no warnings. It’s not a simple switch. It sends an oscillating signal or something like that when it’s working so the ECU would know if it’s not.

Make sure to use good quality synthetic, and I’ll add group IV/V synthetic rather than even M1 0W-40, if following FSS intervals. Otherwise any synthetic should be fine to about 5K miles. Take that advice with a grain of salt. Sixto is not the oil guy.

Sixto
98 E320s sedan and wagon
02 C320 wagon

97 SL320 · #5 02-07-2019, 09:41 PM

Does this car get lots of short trips ( sub 15 minutes of driving / 5 miles / lots of idling ) or is it parked in a very damp garage? Does this person store the car in winter but starts it every few days and only idles it for a few minutes? I've had customers cars with similar issues before.

The very damp garage one was difficult to diagnose, their brother was also a customer / car guy. He went to the garage and found water flowing from the back wall ( built into a hill side. ) The car was driven semi normally but being parked in a very damp area, as the engine cooled, it drew damp air into the crankcase.

Lance Allison · #6 02-07-2019, 10:20 PM

This belongs to an elderly friend of mine who lives maybe 3 miles from town. I assume this car rarely gets completely up to operating temp.

Also should mention the "goo" on the underside of the cap was thick like toothpaste. Not sure if that is good or bad :-) Noted on the dash display "service B 730 days overdue". I'm hoping it just never got reset.

Sugar Bear · #7 02-08-2019, 12:03 AM

Short trips and probably few oil changes are likely the cause. The lack of heat doesn't let moisture get burned out resulting that goo. Change the oil and get it out on some extended full temperature runs if they will allow you and you want to do so. It will probably be fine just don't try to clean it up fast with a solvent.

Good luck, keep us posted!!!

Lance Allison · #8 02-08-2019, 12:12 AM

I'll have the owner change the oil/filter, have the level sensor checked/replaced and drive it a bit.

He has a second home about a 2 hour drive from here each way. I'll ask him to take the E320 the next time he goes up there and will remind him to check on the oil every so often. Then when I see the car again myself, I can look a bit closer.

As always, thanks to everyone for replying.
Appreciate you guys!

Mxfrank · #9 02-08-2019, 12:27 AM

I used to see milkshake syndrome with my '99 E320 when it wasn't being taken on long drives. Committed W210 folks will tell you it's "normal", which is the mindset of the 210 set. I'm sure it reflects poor design. The problem is caused by condensation mixing with oil, due to the cap not allowing much air circulation. Mercedes settled a class action early in W210 production which addressed engine sludge by offering a free oil change. That fixed the symptom once, but the problem was never fully addressed. Clean out as much as you can, change the oil, go for a good day trip.

97 SL320 · #10 02-08-2019, 12:56 AM

Get the engine hot, change the oil, drive the car to hot again. After parking, remove the oil cap and let moisture escape, just be sure to reinstall the cap prior to driving. I'd go through at least a couple of cap off cycles. A large paper on the steering wheel noting " replace oil cap " is a good idea.

Ferdman · #11 02-08-2019, 06:32 AM

Lance, I agree with the conclusion that short drives (which don't allow the engine to reach full operating temperature) cause the condition with the oil cap. Along with an oil change, definitely clean the sludge from the oil cap and the oil fill port. In the future the owner should make an effort to have the engine reach full operating temperature every time he drives the vehicle, even if it means driving an extra distance to accomplish that. I would recommend using Mobil 1 0W40 oil. Walmart sells 5 quart containers for around $24, plus they will recycle your used oil if you are a DIY'er.

Hirnbeiss · #12 02-08-2019, 08:29 AM

I also got some improvement by replacing the thermostat at about the 10 year mark. The original may have gotten “tired” and didn’t let teh engine get fully to normal op temp.

speednjay · #13 02-08-2019, 10:39 AM

Put a quart of trans fluid in the oil. Run it for a few minutes and change tge oil. It’ll clean that sludge up

Zulfiqar · #14 02-08-2019, 11:25 AM

on my E320, this was normal if I didnt drive it for at least 30 minutes and I live in TX.

I have no empirical evidence of reducing this activity, but I did notice that this was a bit reduced when I resealed the breather caps on both valve covers - the passenger side one with the smaller breather hole clogs up completely and you will also see a similar mess in that breather cap usually accompanied by that cap leaking. The driver side cap with the larger hoses is usually very clean.

I used to fill it with 5w40 rotella or mobil1 0w40 and change it at 12000 miles along with a fleece type filter element bought from advance auto parts. The engine was fit as a horse till the day hurricane harvey claimed it.

btw - 2001 model year E320 would be a W210 chassis, I recall all W210 had a full dipstick in their engines, how come you only have the little sealed cap?

97 SL320 · #15 02-08-2019, 11:57 AM

Quote:

Originally Posted by Zulfiqar

I have no empirical evidence of reducing this activity, but I did notice that this was a bit reduced when I resealed the breather caps on both valve covers - the passenger side one with the smaller breather hole clogs up completely and you will also see a similar mess in that breather cap usually accompanied by that cap leaking. The driver side cap with the larger hoses is usually very clean.

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.