I have taken my 300D on several road trips over the past several months - from OKC to Colorado, Austin, TX, and St. Louis (400 - 700 miles). Car runs great - think I could get better gas mileage though - avg. around 22-23 mpg.

But, my question has to do with how much oil I use - 1 to 1 1/2 quarts per 1000 miles. Does that seem excessive? I notice no leaks, no smoking - and when I drive the car around town oil consumption is probably half this.

Any thoughts as to why the difference and what to look for?

Ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

what type/viscosity oil are you runnin?

how many miles on the engine?

__________________
Cheers,
Robert

It is not at all uncommon for a car that uses little or no oil around town to burn some at higher speeds.

Your consumption is within the limits normally considered ok. There is a fair bit of variation from car to car when it comes to oil consumption because of all the variables.

What oil are you using?

edit - oops! Timing is everything!


Tim

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2009 VW TDI Jetta Sportwagon 172k miles (rear-ended harder than Elton John on 8/4/13. Total loss)

1991 Volvo 240 142k miles (T-boned by a stop sign runner. Total loss)

I have only used 15W-40, usually Rotella, sometimes Chevron. Car has 250,000 + miles.

ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Reminds me of my old '79 240D - consumed 1/2 quart consistently each 2 tanks of fuel, thats from dipstick halfway point to bottom line. Yet cross country 80+mph all day long consumption more than doubled. Probly healthiest thing diesel engine can do, think about it.

As I think about it, I imagine if oil gets past rings and valve guides to burn in the combustion chamber, there is likely excessive combusion by-products also going the other direction and getting into the oil.

Not such a good trade-off in my mind... I think I'll take the tight motor.

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2009 VW TDI Jetta Sportwagon 172k miles (rear-ended harder than Elton John on 8/4/13. Total loss)

1991 Volvo 240 142k miles (T-boned by a stop sign runner. Total loss)

sounds a bit excessive, worn rings or valve guides... either way, I'm guessing you are not gonna tear apart the engine to fix it. You could bump up to 50 wt oil in the summer and see if it makes any difference, but its not a legitimate 'fix'.

__________________
Cheers,
Robert

Probably valve guide seals gone bad, but if a new set doesn't last very long, time for a valve job. You are getting due, typically they wear out around 250,000 miles.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Yeah but what y'all are missing is Ryans '78 300D has NO oil/blowby recirculating device that dumps blowby into crankcase far as i know. Instead blowby goes straight into intake manifold same as my '79 240D then gets drawn into combustion chambers where it no doubt assists vital lubrication of valve seats, cyl walls and keeps piston rings happy too.

I stand on my opinion that healthy 250k mile primitive pre-79 MB diesel drawing blowby/oil direct through intake manifold into combustion chambers at constant driven high speed is healthiest thing it can do.

Heck no, this aint oil sneakin "upwards" past piston rings against all diesel logic. Its definitely blowby mainlined through intake manifold, thats why oldies like pre-79 diesels always use a little oil. One qt per 12-1800 miles for them aint unusual at all, lacking blowby recirculation into crankcase you understand.

Meanwhile Ryan, ye aint tellin us what speed ye drive cross country. '79 240D threshold for oil consumption was somewhere around 78mph. Sure as hell haint nothin i ever worrried about.

You stick with yer 250k mile 300D well maintained and watch it reach 420k+ says me. If maintained we never hear of these engines dying between 225 and 380k. Instead its like everybody gets squeemish suffering terror of "high mileage syndrome" dunno why.

Peter, aint seen ye for awhile. Tell us more about cyl head/valve work on 617's. Heard they deserve new headwork at about 280-320k as part of regular maintenance. Now driving and loving 116 300SD at 262k thinkin of pulling the head next year, checking the guides and deffinitely doing seals to boot. Never heard of em needin alot of valve work though.

I have 2 thoughts:

My father once drove his '74 240D from Asheville to Phila, having mostly done 2-10 mile trips for several months before this. He checked the oil before he left, then found himself at least 2 qts low in Phila. He would have checked the oil in the garage, which is level. Assuming that he really did check the oil (he was old enough to be a bit forgetful, and not a "car guy"), my only conclusion was that maybe the crankcase had quite a bit of fuel in it, which evaporated and got sucked into the intake during the hard run.

Another thought is that I read somewhere that these engines are not designed to be run at high power output for more than 4 hours. I have thought I could detect reduced power the last 100 miles in my '84 240D during a 5.5 hour run I made 2 x week for 3 months this year, and my consumption went up moderately (didn't keep records).

Perhaps the engines get hotter during sustained runs as every part is heated to the max, and more oil is burned/evaporated?

Are you using the proper filling procedure? Only add oil (and just one quart) when the level reaches the bottom mark. If you try to chase the top mark, the engine will consume that oil when driven at highway speeds. Nothing wrong with the engine, just normal character.

Driving at high speeds will tend to increase oil consumption.

I've heard of mis-calibrated dipsticks, whereby trying to keep the oil level at the mid-point is actually overfilling, so the engine consumes that oil. You may want to let the level drop a little below the low mark and see if the oil consumption stabilizes. Make sure you have the right dipstick for your car - the handles are color coordinated. Ask at the dealer to be sure.

From the on-line Electronic Parts Catalog (EPC), original part number is 615 010 2172, replaced by 615 010 2372 and 617 010 0872. If your dipstick has any of these numbers, it is correct.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Gentlemen,

Thank you for all the replies. I was pushing it pretty hard I think - probably averaging between 70-75 mph the whole trip using the cruise about the whole way. Last Christmas, I took the car home to Ohio (1000 miles) and noticed exactly the same thing - but the car runs great, decent gas mileage, and I notice no drop in power etc.

I have notice occasional smoking on start-up, but not bad, and not consistent.

I remember reading somewhere (I believe in an owner's manual, which I don't have for this car) a figure for oil consumption, that I thought was extremely high - and that was from the factory when the car was new. I know oil has improved, etc. but it seems these cars were designed to use oil.

I know that my '72 250 manual says that 1 quart per 1000-1500 miles is NORMAL.

ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE