Check out the pic's... anyone know how it got this way?

I finally got around to taking the valve cover of off the 1990 300SEL that I got from my buddy's family who just gave it to me. It's been sitting around for a couple of years. I knew it had the blue smoke out the tail pipe so I'm getting ready to change the valve seals as a first step. There is no "milk shake" in the oil so no head gasket problem of that type. It has a lot of oil at the side of the engine so it might have the typical head gasket outer oil leak.

When I removed the valve cover I discovered the most gunked up valve train I've even seen. It looks like someone poured black marshmallow sauce all over it.

I scraped as much of it off as I could after a couple of hours of work. I've made sure that all the oil drain ports were open down to the oil pan. I then drained the oil, installed a new filter, added new oil including 1 bottle of ATF to help clean things up. I plan to do another oil change after I've changed the valve stem seals and driven it for a couple of hundred miles.

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03 CLK430 Cabrio 211K Pweter Silver/ Oyster Leather
90 300SEL 214k Pearl Black/ Alto Grey/Black Leather

Prior: 85 190E, 88 300TE, 89 300TE, 90 300E 2.6, 90 300TE, 92 300E 2.6, 91 and 93 300SL, 87 Ferrari Mondial Cabrio

Here's what it looked like when I finally re-installed the cleaned oiler tube, cleaned oil tray in the valve cover (missing in the pic) and the valve cover- a spare I had

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03 CLK430 Cabrio 211K Pweter Silver/ Oyster Leather
90 300SEL 214k Pearl Black/ Alto Grey/Black Leather

Prior: 85 190E, 88 300TE, 89 300TE, 90 300E 2.6, 90 300TE, 92 300E 2.6, 91 and 93 300SL, 87 Ferrari Mondial Cabrio

I wonder if the oil was ever changed........

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

I had a buddy just chime in that it might have been caused by the previous owner adding auto store "valve seal fix". It would seem to explain why the oil in the pan was really black and dirty but didn't come out grainy or in clumps. Only the areas where the oil would be stagnant seemed to be covered in this thick goop.

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03 CLK430 Cabrio 211K Pweter Silver/ Oyster Leather
90 300SEL 214k Pearl Black/ Alto Grey/Black Leather

Prior: 85 190E, 88 300TE, 89 300TE, 90 300E 2.6, 90 300TE, 92 300E 2.6, 91 and 93 300SL, 87 Ferrari Mondial Cabrio

good hot run with some cheap 5w30 and marvel oil will clean that out slowly

best buy a dozen case of oil filters

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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)

Run some Kreen in the oil and fuel. That stuff is great.

I'd probably run a bottle of sea foam in it and one of the oils that has more detergents to clean that out. I'd probably do it at least 3 or 4 times within a month or 2 of hard driving. Also, once that @#&% is cleaned up you may have some leaks.

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1990 190E 3.0L

Check the thermostat; engine may have been running cold, a major contributor to a gunky valve cover area.

DG

If this is a longer term car I would lock the chain in place and remove the cam and rockets and clean it completely.

If that's not an option - For now get some cheap Walmart brand 10-30w and some seafoam and do oil changes every 500mi for maybe 4x and see how it looks

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

X2 on checking the thermostat...good idea!

Interesting thread, please keep it updated.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Unfortunately, that's the sludge you can see.
The sump will be full of it as well.
Oil pump and screen are probably covered in it.
Timing chain and drive wheels.

The oil fill is also used in the cooling process of the engine.

I've had an engine which seized under similar circumstances - i.e. very neglected.
I took that engine apart and found the bottom end and oil pump full of gunk. The lubrication to the tie rods and big end bearings were not getting through to do their job because the gunk was blocking important access holes.

Sitting around for a couple years?

Heck, that sludge did you a favor in preserving metal lol

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Allen Kroliczek
Oak Grove Autosport | Oak Grove Autosport
01 G500, 82 300TD, quite a few more.....

Benz Mondi, it would be a good idea to remove the oil pan and check the bottom end of this engine, and thoroughly clean the oil pan, etc. Now you understand why your buddy's family gave you this 1990 300SEL.

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Fred Hoelzle

send a dollop to Blackstone and see what the analysis says :-)

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-- raymond~
47º 34'N 122º 18'W

I like this idea!



I would gladly take another neglected 300SEL. Not great for around town, but nice freeway cars.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]