On my 1982 300D turbo (200K miles) I used to add about a quart of oil every 2000 miles. recently oil consumption has gone up to more than 1qt every 1000 miles. i went on a crusade to fix external oil leaks but not too much was leaking. When i take off the oil fill cap it puffs like a choo choo train so i think the blow by is excessive. The air filter was getting drenched with oil on one side (I resealed the leaky oil trap cover with silicone) the exhaust tail pipe has a thick coat of soot as well. Oil trap drain is open (I poured oil down it to check). I noticed some oil around two of the head bolts (star heads). thinking it was the valve cover i cleaned them off but a small amount of oil reappeared back at the two head bolts. Should i retorque the head? Could that be the oil burn problem?

I plan on pulling the glow plugs to see if there is oil associated with one of the cylinders more than another.

I bought the car 30k miles ago from the original owner. About 50K miles ago the PO's mechanic (The Diesel Stop, in San Gabriel, now out of business) replaced the piston rings, main & rod bearings, head & flywheel bolts. Also grind crank, re-size rods. Compression after work completed was noted as 300, 280, 300, 320, 280. Complaint was excessive noise and low oil pressure.

Maybe unrelated but the engine shakes more at idle. I adjusted the rack bolt but no difference. Power is still OK with engine.

Any suggestions?

Thanks

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1972 450SL
1982 300D Turbo

Those are very poor numbers for having new rings. (I wonder why they are no longer open???) Unless it still needed a valve job after the rings were done, all the cylinders should be in the 350-450+ range. The cylinder head was off and they were doing so much work to it already, a valve job should have been done at the same time.

With only 50k miles, there should be no reason for the head to leak if the job was done right. Mabye they didn't re-torque the head after it was run to operating temp???

I doubt torquing the head bolts will do much,but you can try. Have you done a compression test now, or are those numbers from right after the rebuild? It sounds like the rebuild has some issues.

If those numbers were from right after it was put together then they sound about right. You need to put at least 500miles on them to get the rings seated and "broken in" properly.

"When i take off the oil fill cap it puffs like a choo choo train"
That's not *always* a bad sign. I know quite a few MB diesel engines that have blow-by like that and run very well (My 320K mile engine, for example, can still start without a block heater on 0*f days). All engines are going to have some blow-by no matter the age, miles, or design.

"the exhaust tail pipe has a thick coat of soot as well"
Part of the diesel life. I can't think of a pre-2002 diesel exhaust that has no soot in the tailpipe.

"I adjusted the rack bolt but no difference."
Is the rack damper a kind of gold color? If it's not, it could be the old style with a weak spring. What RPM do you idle at?

but what kind and weight of oil are you using?

also those numbers are normal if the compression was tested cold.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Others on this forum have mentioned turbo seal failure with such high oil consumption. If I recall, not very expensive to repair with a kit.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Retorquing the head won't buy you anything.

In fact, I'd bet that the oil that you see around the head bolt remains from the leaking valve cover. They can be a PITA to seal completely and the proper torque on the nuts is critical.

If you are getting an extraordinary amount of oil in the air cleaner and blowby is high, the chances are good that the bottom end is marginal and the oil is passing to the engine via the breather.

As mentioned, it's also likely, on high mileage engines, that the turbo seals leak some oil as well.

The combination of high blowby and leaking turbo seals will result in some serious consumption.

This one has very little blowby but is consuming a quart every 1500 miles...........most likely due to the turbo seals.

that retorquing is unlikely to help.

but it prob wont hurt either.

again i ask about oil because if using the wrong type or if not changing often enough, stuck rings can result.

and if that is the case, sometimes other action can help besides tearing it down.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Thank you for all your responses.

I am using Delo 400 15W/40. Change w/ filter religiously every 3K. PO was a stickler for maintenance as well. the rack damper bolt is the new upgraded one with the stiffer spring.

Oil is not leaking from valve cover. Several of you mentioned turbo seal leaks; How do you tell if the turbo is leaking through the seals. the seals i know about are not leaking (oil return from the turbo and the air intake seal to the turbo). Are there others?

I don't have a compression gage for diesels (do you have to remove the injectors or the glow plugs to tap in?), maybe I'll try to borrow one if you think i need to. I'm surprised no one mentioned doing a leakdown test, but again i don't have this tool.

Here is the receipt the PO gave me for the engine job. No mention of head work, except the customer was charged for "complete gasket set". Now that i look at the receipt again the compression numbers appear to be values before the rering since they are listed under "system analysis" (sorry for that confusion). Repairs were done 8/98, 50K miles ago by "The Diesel Stop" (no longer in business):

Parts:
1 set piston rings $120
1 set main bearings $86
1 set rod bearings $82
1 set head bolts $68
1 set flywheel bolts (does this mean they pulled out the engine?) $15
1 complete gasket set $195
1 oil filter $14.95

Repair order - Labor instructions:
Troubleshoot and repair excess noise condition/low oil pressure.
A. System analysis - compression test 300, 280, 300, 320, 280.
B. R&I engine assembly
C. Clean and inspect all components
D. Reassemble engine w/new components and gaskets to stop oil leaks.
E. complete settings.
F. Performance test.
Labor: $1500
Sublet repairs:
Grind crankshaft
Resize rods, check pistons $400

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1972 450SL
1982 300D Turbo

This is somewhat difficult to confirm. But, if you are agressive, there is one test that you can perform.

First, make sure the oil level is precisely at the full mark......no more......no less.

Then, take the breather off the air cleaner and route it into a bucket of some sort. Make sure that all the oil from blowby will NOT go into the engine and WILL end up in the bucket.

Drive it for at least 1000 miles. Yes, it's quite a bit, but, the only way to confirm the culprit.

If the bucket fills up with oil............meaning 1 quart........at 1000 miles........blowby is the culprit.

If the bucket doesn't fill at all..........meaning 1 cup or less.........at 1000 miles........the turbo seals are the culprit.

Note that I just invented this test..........LMK how it works out.

Eh, thats not that many miles, with some coffee/food I could probably pull that off in one day. My nonstop record as of yet is about 820 miles in 12 hours......(some was at 55mph...thats why it took longer) Second place is 760 miles in 10ish hours....

Sounds like a great test though, I will remember that if consumption increases on either of our cars.

Our van looses at least half of its consumed oil from blowby, there was a big drool of it all the way down the multiple-part air intake, and a sopping puddle in the bottom where the air filter is. 82k on it, pretty sad. plus, it blows blue exhaust, so its probably burning it too. uses about 1qt for every 1300miles or so....

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

pawoSD--just curious, but is that the 3L V-6 in the Caravan? I ask because I used to own a '91 Chrysler LeBaron (think Plymouth Acclaim w/ vinyl roof, grandma-plush interior, and digital dash!) that had that engine and good god!!!! did that thing burn oil. I started using that gunk you pour in w/ the oil once it got really bad--I HAD to though, because if you sat at idle at a stoplight for more than 45 seconds, the plume of oil smoke that thing let out was amazing. That being said, the motor ran well, and the car was quite fast--I sold it with 261,000 miles on it to an employee, whose son did a head job and replaced the rings. So the car now has almost 340,000 miles on it.... Only high dollar repair I ever performed was a transmission overhaul at about 175,000 miles--guess it'll be due for another one of those soon....just this time I won't be paying for it.

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Christopher
'06 Mercedes E350 station wagon (silver/black)
'85 Mercedes 300D (black pearl/palomino)
'85 Mercedes 300SD (smoke silver/burgundy)
'79 Cadillac Sedan DeVille

'05 Toyota Camry (because always running is nice)

'85 Mercedes 300D sold back to orig. owner 8-1-06
'84 Volvo 264GL Diesel, owned 2000-2013

No wonder The Diesel Stop is out of business. The poor mechanic worked himself to death. He was charging prices like he was working on his own car. He should have visited a dealer and asked how much was a 125,000 mile service and he probably would have been quoted close to $1500.00 and I know he would have hit $1500.00 if he had said: by the way how much to change a glow plug with that? That's why I can't go into business as a Mercedes mechanic. I don't know how to charge folks like the dealers do.

BenzDiesel

"1 set flywheel bolts (does this mean they pulled out the engine?) $15"
"B. R&I engine assembly"
You answered your own question.

"Compression after work completed was noted as..."
"A. System analysis - compression test 300, 280, 300, 320, 280."

The compression numbers in your first post was *before* the work was done. The low numbers were likely the reason a ring job was done.

$1500 for the work and $400 for outsourced work? Thats a heck of a deal. Many other places would be in the $2000+ range.

I know when I pull and replace a Mercedes engine, it takes me about a whole week to recover, physically. It takes longer than that for all of the oil to get from under my finger nails and keep my pillow case from getting dirty from all of the embedded oil and transmission fluid that I had wallowed in. I wouldn't do all of that work for $1500.00 for my OWNSELF!!! I charge me about $4500.00 for the labor and put it on credit and pay it off over time as the engine build up miles. But $1500.00 to do that for somebody else??????, when Mercedes dealers charge almost that much ($1500.00) to change your oil and brake fluid and wash your windows. I don't think so.

BenzDiesel