Diagnosis confirmation please.
 

My 300SDL has started smoking and consuming lots of oil. The smoke smells like burning engine oil and is gray/blue. No blowby is detected if I remove the filler cap while the engine is running. The interior of the compressor side of the turbo is oily and has a small puddle in the intake. The turbine side is sooty, not oily.

I suspect a failed turbo oil seal on the compressor side. What do you think?

I'd suspect the same.

I don't think you have enough evidence to conclusively decide that the turbo oil seal has gone bad, although that is the likely conclusion. You could still have some kind of higher-rev blowby situation or something like a worn or unsealed valve stem.

You may be able to isolate the problem further by pulling off the intake crossover tube and running the engine a bit that way. If you are getting oil blowing up from the turbo I'd say you have it traced.

Also, I think the blowby is vented to a location just downwind of the EGR valve (can't remember exactly). You could always make a few test runs with the blowby tube connected to some longer piece of tubing hanging down the side of the engine. It would blow out that tube onto the ground instead of burning.

I'd hate to see you tear into the turbo and then find it was some other cause.

Ken300D

I agree.

These can suffer a head gasket failure that dumps oil from the timing chain cavity into #1.

The characteristic failure of the turbo is very low oil smoke at idle. The airflow is not sufficient to carry the oil up to the crossover tube..........so, it's pooling in the riser tube. When you mash the pedal, this pooled oil flies into the crossover tube and down to the cylinders resulting in massive smoke upon initial acceleration.........gradually decreasing to a modest amount of smoke after the initial wallop.

Thanks all for the input.

The crossover tube interior is pretty oily.
That's almost exactly the smoke scenario we're encountering...modest smoke being a visible trail at any speed. Consuming a lot of oil too...2-3 qts in 90 miles.

Can't run it w/o crossover tube...I pulled the turbo this afternoon.:rolleyes:

BTDT. Usually, it tells you that it's down 3 when the oil pressure gauge starts falling off the peg........:eek:

Actually, you can start it without the tube and observe the oil pooling at the output of the turbo.........it starts to gurgle down there.

It never rains, it pours.

We've known this car (the $650 SDL) had oil consumption issues for a while. Sometimes, it would suck down a qt in 1000 miles, other times it would go for 3500 using hardly a drop. Being a cheap ride, I elected to fix when broken and not before...

Fast forward to about a month ago, when my stepmother was hospitalized with a head injury and Bride and I jumped into the SDL and haulled ass to Bryan, TX, about 2 hrs from here. After an almost all night vigil in the ER, we drove back to the farm (60 miles from Bryan) to spend the night. I drove Dad (he can't see well at night) in his car so I'm following the SDL and it's exhibiting the symptoms above...thick smoke at take-off and a moderate plume at cruise.

Smoke at this volume is a new development.

The next morning, I check the oil before sending Bride back to Austin. It OK so I send her home. When she gets home, she reports that the car is smoking REALLY bad now so, I worked out an arrangement for my daughter to return my 300D and pick-up the 115 for a driver so that Bride could park the SDL and drive the 300D until I could look at it and figure out what has happened.

Meanwhile, the 115 pukes its engine without warning and I put Daughter in the '83 wagon. So, now I'm driving the 12mpg PowerStroke I use to haul the dozer:eek:...I'm also looking for a turbo for the 603 but am coming up empty handed.

Anyway, I'm back in Austin today and decided to yank the SDL's turbo...I probably should just rebuild the damned thing myself but, I have ZERO time to screw with it. I'm tempted to ship the SOB to Ron's in UT and have him rebuild it, and be done.

Yep.........I know.

The vehicles are running acceptably well..........but the people and the animals are in bad shape. 1 down........1 going down........and I'm waiting for the third shoe to drop.

It's hard.

I was at PNP today and there was a W124 with an OM603 I believe. Turbo was still there. Don't have any idea what brand.
Found odo in the floor of the car. 557K!! :eek:

Would the leaking head gasket cause a similar issue of "loading up" at idle then blasting all that smoke out upon acceleration?

My SDL does this BIG TIME and I'm not entirely convinced my turbo is toast (although I'm pretty sure) as there are many quirks the 603 exhibits that could be my issue. It runs fantastic aside from the huge smoke show

One concern is that my oil consumption is not huge like others exhibit, maybe two quarts over 5000 miles. So I'm at turbocharger, headgasket, or valve guides/seals... I resealed my IP already and the oil cooler does not leak.

We'll know more in a few days...the SDL's turbo rides to Waco today for a makeover at Majestic. It should be done by the time I get back from AZ; I'll stab it back on sometime next week.

I'll post the results then.

I never had a head gasket failure on the 603.........to my knowledge.........so, I can't comment personally. But, I would not think that the head gasket failure would have similar symptoms as the turbo. The oil leak to #1 would be gradually increasing as crankcase pressures rise.........so, you'd get moderate smoke at idle and increasing smoke with rpm's. The increased smoke with rpm's might not be noticeable if it dissipates with airflow behind the vehicle.

The '86 consumes about 2 1/2 quarts in 5000 miles. I'm convinced it's the turbo and one of these days I'll get my lazy ass out there and pull the damn thing.

It takes about 45 minutes. Gityerassingear.

What kind of turn around time is Majestic offering you? And what warranty? The T3 bearings/seals are only around $40 last time I bought them (and promptly lost them).

They would have done it while I waited, if I'd cared to stay in Waco,TX for four hours on Thursday...I don't know about the warranty. I'd have done it myself but, don't have time right now to mess with the seals.

I told them to work it into their schedule and I'd pick it up this week.