Is 1 QT oil/1000 miles too much on an 88 560SL?

[toms560]

My 560SL with 116K goes thru one quart of oil per 1000 miles or so. I've heard both ok and bad, just looking for opinions. No smoke or visible leak or loss. Maybe valve guide seals? Should I just put in the oil and tear the motor down when I have higher mileage and really need to do more? Thnkx.

[al parker]

Hello,
I don't think that's too bad. For me it would not lead me to an overhaul or rebuild but....a lot of it depends of what kind of oil you're using, your driving style, and the use of the vehicle.
I've had vehicles that used a lot of one brand or grade of oil but when changed over would actually sonsume (burn) less oil.
Severe service or hard driving can make an engine use oil.
Luck
Al

[cbdo]

Make sure you're using the right viscosity. At my first oil change they used a standard 10W30, which disappeared at the rate of a quart every 5-600 or so in summer driving--but the manual specifies that weight for ambient not over 50 degrees F. I now use 20W50 in a high-mileage-engine formula, and a quart goes well over 1000--maybe 1500 or so.

[David Langsam]

That sounds a lot like valve stem seals. Mine went through a quart every 500 miles. I had them done at the same time I did the timing chain. Doesn't consume even a drop now.

If you check the tail pipe first thing in the morning after it's been sitting all night, you should see some smoke.

David

[stephenson]

You did not note if you use synthetic oil ... I would, prior to great expense, consider changing to Mobil 1, let it clean things for about 3K, then switch to a slightly thicker M1, and see what kind of experience you have.

I have heard of the synthetic cleaning effect being put to good use this way ... if you could decrease the burn rate a bit, you could simply accept the loss of the oil as not a major factor .... carry a few quarts with you and not worry about spending $1500 to save 12 quarts a year X $4.00 a quart = $48 ... take a long time to pay that back ... and, you will likely end up with some loss per 1000 miles even after what work is required (if valves and/or rings expect more like $3-5K for repairs, making math even more in the "more oil" category).

[KirkVining]

Originally posted by cbdo
Make sure you're using the right viscosity. At my first oil change they used a standard 10W30, which disappeared at the rate of a quart every 5-600 or so in summer driving--but the manual specifies that weight for ambient not over 50 degrees F. I now use 20W50 in a high-mileage-engine formula, and a quart goes well over 1000--maybe 1500 or so.

I had the exact same experience on my 280SL. As soon as I switch to 20W50 it stopped - I'm not burning even that. I think the engines are just designed for a heavier oil. I do know that from building hot rods back in the 60's that engines with more forged parts are harder on engine oil, which is why 20/50 was called "Racing Oil" back then - it lasted longer in an engine with more forged parts. That might be the same reason in a Mercedes.

[cbdo]

In my case, there was no great intellectual insight in the decision--just a matter of RTFM, 'cuz the chart was right there in print.

[mottgrand]

I agree with the oil selection comments. In my 88 560sl with 90kmiles changing to high viscosity oil doubled milage (1000 to 2000) in mid-summer. Still I am planning to do valve seals when I will do the timing chain at about 110 k seems common recommendation. Will probably save a lot compared to doing them separately.