Excessive oil consumption
 

Ok, now that I have the car actually running I took it on a short trip today. All in all aprox 100 miles round trip. I started out with topped off fluids including the oil. By the time I had gotten back to town my oil light was flickering. I thought initially this was just thinned out oil and low oil pressure (my air cooled vw would do the same thing).

When I checked the oil, it didn't even register on the dipstick. Granted this was after immediately shutting the engine off and I haven't checked it after it sat for 30 minutes, but any ideas what could make it use/loose so much oil in less than 100 miles?

I don't think it's leaking it out and the car isn't smoking THAT much, or atleast I didn't think it was.

Prior owner confirms that this is typical oil useage for the car since she got it.
I have several ideas like re-ringing the pistons, valve seals, valve job....
but where should I start first?

-Tim

The guy that had it before the person I got it from was using conventional oil in the car, not oil for diesel engines, I don't know that this matters much but thought I might ought to add that small bit of info. Also, I don't think it is leaking oil at that fast of a rate, but there are puddles of some liquid collecting on the air intake manifold. It's not thick enough to be oil, doesn't smell like diesel or antifreeze. I'm sure it's oil but definitely not oil consistency. It's dripping at the front of the mainifold and making its way towards the ground, though some of it is hitting the exhaust manifold.
-Tim

What oil are you running in it now? Diesel rated oil is quite a bit different. Do you still have the oil seperator on the valve cover? From top to the bottom of the dipstick is at least a quart or more of oil. If its not pouring all over the ground I cant see how you could burn that much in only 100 miles without some visible oil smoke.

Jason

That sounds like excessive blowby. I used 27 quarts of oil in 500 miles when I first drove my D24T home. I dumped in 2 quarts every 50 miles. Yeah, I rebuilt it rightaway.
A lot of the oil went from the breather into the intake....then out the tail pipe.

Steve

27 quarts in 500 miles???!!! Holy crap and I thought my car used some oil! WOW

Jason

Ok... Let me just hit each question...
Rotella 15-40, same as in my Dodge Cummins

oil seperator??? I have a rubber tube from valve cover to air intake that is an exhaust gas recirc of sorts... whats an oil seperator?

It's not pouring out anywhere though there is smoke when it runs but NOTHING like I would think you would see with a quart every 25 miles which is about the rate I'm loosing it.

The smoke that I am seeing is white or whiteish-blue. I did romp on it twice on my return trip home and got pretty good rolls of black smoke, but then that was expected when I did it.

It has been pretty cold here and since the 3 new glow plugs that I put in last week the car is firing right up and the motor sounds quite strong. I've never had an engine need rebuilt that started so easy.... It's hitting on first crank every time.
Planning a compression test, but really wonder if this is the issue.

Thanks for the feedback.
Tim

Due to their extreme high compression compared to gas engines, diesels can burn quite a lot of oil and not have any major visible smoke. You could pour straight motor oil into your fuel tank and the engine would run OK on it. The heat and pressure in the combustion chamber are so high that it will burn almost anything.

Your situation sounds like a combination of factors, leaking and burning both. The stuff collecting on the intake runners is oil from a leaky valve cover gasket. The cork gaskets on these engines are notorious leakers. If you install a rubber 1-piece one, available from Volvo or some parts houses, it solves the problem. Check your valve clearances while you're in there.

The main thing going on is almost certainly worn, damaged and/or stuck piston rings. Valve seals or guides cannot cause that much oil consumption. Using non-diesel-rated oil is likely a big part of the problem here. Diesel oils are formulated to handle the soot production and different kinds of stresses found in a diesel engine. If gasoline engine oil is used, serious sludging and deposit problems can result, which will gum up the rings and prevent proper sealing. That may be part of what's going on in your engine if non-diesel oil was used for a long period of time. If that is the case, you may be able to help free them up by using some different types of oil, such as Lubro-Moly's MoS2 anti-friction stuff or a good lightweight synthetic, or even some additives like Marvel Mystery Oil or Rislone. However, that can turn into an expensive experiment since those oils are not cheap when you're burning through it as fast as you are. You may see some positive results, but then again you may not.

There is also the possibility that the rings have been damaged by overheating, or are just plain worn. I used to have a VW Rabbit with the 1.6L diesel (same as a D24 with two less cylinders). When I bought it, it used over a quart of oil every 100 miles. I tried different oils and additives and it made no difference. I pulled the head off and had it rebuilt with new valves, guides, seals etc, and that made no difference either. Finally I took the pistons out and discovered that the rings were shot -- cylinder bores were OK, but the rings had had all their spring cooked out of them by someone overheating it in the past. I gave the cylinders a light hone, cleaned the pistons and installed new standard-size rings and it was completely fixed. That engine never used so much as a drop of oil again. I drove it all across the country and never once added oil to it.

Even when it was burning through oil like crazy, the Rabbit always started and ran perfectly and barely smoked. I couldn't believe it could be the rings until I finally tore it down.

My guess is that your situation is similar.

D24 engines are like humans they are all different! Some engines drives normally but uses alot of oil like imbodies car. Some engines get hard to start when cold and som engines start perfectly when cold but not if it is warm.
And some engines are very slow.

You might try BG109 compression restore. Its supposed to be able to free up stuck rings and dissolve carbon build up. It would be worth a try I doubt your consumption will get any worse!

Jason

I hate to tell you this but my engine used a quart in 25 miles. When I pulled it down, the top piston ring gaps were more than 1/4". One was broken.
Amazingly it would crank up quite easily and did not seem to use oil.....until you drove it.

The guy I bought it from said check the oil on the way home so I checked it after ~100 miles. Fortunately we stopped for food. It took 4 quarts to get it back to the dipstick mark.

The engine and had less than .001" wear in the bores and I rebuilt it using the same pistons. Same engine will use a quart in about 2-3000 miles now.
The starter ring had some teeth missing too so I had to remove the engine anyway.

Steve