'85 280SE oil usage

Perhaps I should add the following: The engine smokes after running for 1 minute or so, and stops smoking when it heats up after perhaps 5-10 minutes. It is much worse in cold weather - ie when below freezing point. The smoke is white-ish I think.

I have seen black/grey like smoke when giving full throttle. Also at kickdown - when engine was not entirely warmed up.

And more: I'm not only a Mercedes newbie - I'm also an engine newbie. Never realized what I have missed out on - until now.

Best Gunnar

Gunnar Langemark wrote:

You didn't say how many miles / kms on this engine. Engines use lube oil for three reasons: leaks, wear and lack of maintenance.

Leaks are just that, look for clean oil stains on the engine and underneath - by clean I mean more oil than dirt indicating a large enough leak to carry away the dirt.

Wear of the piston rings is inevitable in any engine, good maintenance simply allows the rings to last longer. A compression test will tell if the rings are worn, if so, an engine overhaul is needed - such an engine probably has done 250K miles / 400K kms.

An uncontrollable oil user is worn valve stem seals; these plastic seals wear out and allow lube oil to be sucked into the intake manifold. Some engines have this problem much sooner than others - it's quite variable. An experienced M-B mechanic can replace the valve stem seals without removing the cylinder head, a job that costs about US$500 in the US.

Some engines suffer from lack of maintenance - specifically, oil changes. The inside of the engine gets dirty and the piston rings no longer seal as well as they should. The cure is a few frequent oil and filter changes, say every 5K km and some long trip driving so the engine really runs at a good speed for some hours.

Most auto manufacturers will tell you that 1 ltr of oil consumption per

1K km is "normal." I don't but I expect 1 l. per 8K to 10K kms from a relatively new car. The harder a car is driven the more oil it will use. If your car has done over 150K miles / 250K kms some oil usage is to be expected.

Oil you buy has specifications. The low SAE numbers, 0, 5 & 10, indicate very thin oil and the higher numbers, SAE 40 & 50, thicker oil. You should use SAE 10 - 30 in the winter and SAE 20 - 40 in the summer. Don't use very thin oil in this old engine.

Finally, don't confuse water vapor in the exhaust during cold weather with oil burning. The smoke you see upon hard acceleration is mostly soot being blown out of the engine and exhaust pipes.

I hope this helps you to understand your engine's needs, not only this one but those that you'll buy in the future.

T.G is right! don't use thin oil in OLD worn engine like yours! (please do a compression test "WET" & "DRY" test to comform your engine condition first). I would use higher viscosity "thicker" oil in OLD ENGINES!

HAVE A NICE HAPPY THANKSGIVING

CSC

Thank you all for your answers, T.G. Lambach - you bet I can use your explanations. This is exactly what I need to make sense of all the small bits and pieces I pick up here and there. I'll be catching up on engines during the winter, and I have pasted your answer into a document I'll be keeping.

I'm an IT guy, and not an engine guy (yet).

The engine IS old, and has some 200k miles on it. So I guess I'll be using a thicker oil.

Best Gunnar

I added some SAE10W/40 Mobil - and plan on changing oil and oil filter this weekend. I just bought an engine manual and a chassis manual on ebay, so I guess I'll be alright.

I run two kinds of trips: 5-10 km twice a day and once or twice a week

2x50 km with a 20km stretch running at appx. 120-140 kmh. Probably the short trips are hard on the engine.

Gunnar

Suggest you buy a small note pad and keep a record of the engine's oil consumption - the amounts of oil added and the mileage of each addition. Also record each oil change. After six months you'll see a pattern or you'll find it doesn't burn much oil.

It's always better to deal with facts than one's memory.

T.G. Thanks for your advice. I already bought such a book, and I'm taking notes. I'm learning as fast as I can. I love this car - and this new hobby. :-)

Gunnar

T.G. Lambach wrote:

You shouldn't mix oil grades... This is like putting a mix of large and small marbles in a can and then shaking. They will seperate.

Sorry about the empty message, I spazzed. Marty

Thanks Martin, I has some speculation about that, but decided to do it anyway - and I changed the oil and the oil filter yesterday, so it only ran for about

40 miles with what MAY have been mixed oil grades.

So I found a DIY garage with a lift and did the oil and filter change. I was quite astonished to find that in the bottom of the canister - or container - that holds the oil filter there was quite a lot of sediment

- like tar or asphalt, which was hard to remove. Is it normal that there is a milimeter thick layer of such residue? As you may have noticed I'm quite new to engine and have next to no experience so I'm depending on kind people I meet - and the expertise on this list.

I feel that the motor runs a little better after the oil and filter change. It still smokes a little - but stops faster I think. I'm not sure however, that it is not just the general cold and humid weather here in Denmark that plays a part here.

Best Gunnar