Oil loss with no smoke???
 

I have an 81 300D with a real hunger for oil. The problem is I dont know where its going! I am using a quart every 800-1000 miles(about 1 week of driving). There are usualy 1 or 2 small(pea sized) drips in the driveway,but thats not near enough to account for a quart per week. There is no visible smoke in the day time unless under hard acceleration. Any ideas where all the oil could be going? Is it possible that the tiny drips are adding up to a full quart per week? The car starts up fine, even when cold and has normal power for a non-turbo diesel. The engine has about 50k on a complete rebuild. Any ideas??
Thanks!
TJ

I believe I remember the Tappet brothers arguing that you can burn a quart of oil every five hundred miles without it being visible in the exhaust.
I have found that using different brands of oil and different viscosities can have a big effect on how much oil the engine consumes. For instance, using 10-40 in my Olds 455 in the summer when temperatures are over 105 will result in significant oil usage. Put in 20-50 and the oil usage drops precipitously.
I think if you look at the Mercedes literature you will find that using that much oil is well within acceptable limits for their diesels. I would not worry about it if it were my car.

A drip every minute or two will be at least a quart in 800 miles. Find the leak and fix it before getting excited about oil consumption. After all, the 220D usually eats a quart in a quarter tank..... Most usual places are leaking valve cover gasket (easy fix), leaking blowby tube, or misc. dribbles from leaking chain guide covers, etc. There are several bolts that go into the chain case up front, and if they dont' have sealant on them, leak oil out.

A diesel will consume massive quantities of oil before it shows blue smoke -- usually only see blue on startup with bad valve guides or guide seals, or if the turbo seals are shot and you are blowing oil down the exhaust pipe, or if the vac pump diaphram is holed, and then only at idle.

Peter

My 1977 300D
 

"Consumes" oil at the same rate. I have a leak at the oil filter housing/engine block gasket (too lazy to fix it) and I do get a little blue smoke at start up, especially when cold. After that, the only time I see a hint of smoke is when I have one of my NJ idiot commuter "friends" tailgate. Usually I feather the throttle a little and give him/her a face full. Then they back off.

Kind of cool, like having a 007 smoke screen.

Don't worry about the level of oil you're consuming, just consider it a handy anti tailgating device.

JCD

About 2 years ago I always found tiny drops of oil under the car.
I put a can of STP brand "stop oil leak" in my car. Ever since I do not see any more oil leaks.


David

___________________
1985 300D Turbo

"A diesel will consume massive quantities of oil before it shows blue smoke."

"you can burn a quart of
oil every five hundred miles without it being visible in the exhaust. "
My 240 is a prime example of how true these statements are... I am burning a quart in less than 250 miles...and you would not notice any soot/smoke if you saw me driving around... my 81td was much "smokier" and only used normal amounts of oil... most smoke from diesels is unburned fuel...'properly' burned oil is almost invisible compared to improperly burned fuel....