Advice needed please - Page 5 - PeachParts Mercedes-Benz Forum

kerry · #61 07-26-2008, 11:53 AM

Sounds like the turbo oil seals (and bearings?) have gone bad and it is sucking oil in thru the intake and running on that oil. This would explain the white smoke. This could be a result of a leak in the turbo oil line causing inadequate lubrication to the turbo. The oil coming thru the turbo would account for why it won't shut off when the diesel fuel is shut off at the IP.
I'm guessing he's going to need a rebuilt/new/used turbo.

kerry · #62 07-26-2008, 12:12 PM

Now I'm thinking something else. Could the original problem have been that the turbo was seizing up, restricting air flow into the intake and the additional oil got it turning again but now the source of the problem has become obvious?

Hatterasguy · #63 07-26-2008, 12:56 PM

Could be, sounds like this car has a bunch of issues. Someone is going to have to go through it when he gets back.

barry123400 · #64 07-26-2008, 07:42 PM

Quote:

Originally Posted by kerry

Now I'm thinking something else. Could the original problem have been that the turbo was seizing up, restricting air flow into the intake and the additional oil got it turning again but now the source of the problem has become obvious?

Good thought but the injection pump was refusing to supply fuel reliably. In almost if not every time the engine quit there was no fuel out of the injector lines. In fact for quite awhile it was almost impossible to get that injection pump to deliver any fuel to start the car with from the mechanics posts.

The oil leaking line might have starved the turbo bearings I agree as well. I really doubt this though. More likely too much air mixed with the oil instead. This could have contributed to the slowdowns after warmup that where being experienced while the car was being serviced. Just dragging the turbo down with overheating and binding turbo bearings maybe as soon as they got hot. Yet after the three quarts of oil was added the car did at least ten hours with no replay from what I can accertain. At this point I would really wonder how much base oil was still present. Did he let it get low again? I suspect he did.

Now he has a redundant fueling source unfortunatly with the turbo seal or seals out as well. I only hope he checks his base oil quite often as he is now really using the base oil as additional fuel. Thats if he is still driving or trying to do the last eight hours.

Tough trip. Could happen to anyone. This whole thing may go down in the records as no really accurate knowledge of the cause of the original problem was ever truly established. Even so called hindsight that makes things pretty easy usually is not very productive on this one yet. At least not to me.

If I have learnt anything from this episode though. It is these cars may not do well when three quarts low on the highway. Even though they hold so much oil in comparison to a gas engine. The five quarts remaining may not be enough to give a constant steady supply of oil. Instead a lot of air is mixed in perhaps.
The oil pressure gauge would probably remain pinned when this was happening. The air would compress as soon as the oil pump picked up another shot of oil. The air/oil cycle is so fast the gauge might not react. Yet you might have a very large portion of air in the system as well as a little oil. Just a supposition. Probably wrong as well.

kerry · #65 07-26-2008, 09:22 PM

I was thinking that the original problem of slowing down was caused by lack of air due to an issue with the turbo. The open fuel cap was misleading and they immediately began looking a fuel issues. Disturbing old fuel lines can easily lead to air leaks which were introduced by the attempt to fix the problem.
With the additional oil, the engine began breathing properly, allowing them to fix the air leaks.
All this is speculation but mechanical mysteries are always intriguing.

My Wanderlodge with a CAT 3208 had similar symptoms after I first bought it although it was shutting down abruptly. I thought it was the turbo. Turned out it was a dirty air filter. Between the air filter and the turbo was a rubber 90" fitting. When the vacuum caused by a fast turning turbo got high enough due to inability to draw enough air thru the filter, it would suck down the rubber fitting, cutting off all air to the engine. Engine would stop. It would then immediately restart because the rubber fitting returned to normal once the vacuum was removed. Lucky for me I found I mechanic who had experienced the exact same problem in the previous six months. Both were caused by an exhaust leak near the air filter allowing soot to dirty the air cleaner.

miljohnj5 · #66 07-26-2008, 11:08 PM

After two years with minimal problems, my car decided to give me a second close encounter that occured this morning as I began just inside the Texas border on I40 toward Amarillo. Mein auto started lagging at higher speeds (55-65). I stopped after driving for less than an hour to add more oil because of a slow leak. I started it up and it began stumbling. I put it in park and revved the engine and it just took off, rpm's went through the roof and tons of white smoke poured out the back. I waited a while and checked for any additional oil leaks, none. Started it up, ran fairly well. About 10 miles later, climbing a hill (climbing hills-a consistent factor throughout my ordeal, either leads to fluid level differentiation or simply engine strain- tough call) and started to stall out so I pulled over and put it in neutral and gave it fuel, the engine took off again and redlined in a hurry before I could shut it down and the engine temperature sky rocketed- I thought ole Dixie bought the farm. The engine shut down but not right away. I waited almost a half hour this time to start it up. It didn't start right away and took several attempts while HUGE clouds of white smoke poured out the back. After it started I noticed a ticking so maybe (as suggested by STJAMES) a lifter blew. Would that have also caused the engine rpm's to run away too if it was sticking? The engine runs strong now but the ticking is still there. Is it a lifter possibly? How much is that? Geez... these are the times that try Benz souls.

kerry · #67 07-27-2008, 08:40 AM

No lifters on these engines so that's not the issue. It sounds as if your turbo is having problems. Read a few posts back up the thread and see that people think the turbo seals have failed and the engine is running on engine oil being introduced thru the turbo. Sound could be a bad turbo but it also could be something else if engine redlined for a while with no load on it.
If you're having to add oil every hour, then there's a serious oil problem somewhere. It's looking like the turbo could be the source.

Hatterasguy · #68 07-27-2008, 11:59 AM

How many miles are you getting out of a quart? It sounds like Brians 300SDL with a badly blown turbo. But not blown enough to lock the engine with oil.

When the engine is revving up like that it's consuming the oil from the turbo seals, so your lucky you were able to shut it down. At some point its either going to choke on the oil, or run away and blow apart.

Do you have AAA? I'd consider towing it.

barry123400 · #69 07-27-2008, 09:05 PM

[QUOTE=kerry;1921880]I was thinking that the original problem of slowing down was caused by lack of air due to an issue with the turbo. The open fuel cap was misleading and they immediately began looking a fuel issues. Disturbing old fuel lines can easily lead to air leaks which were introduced by the attempt to fix the problem.
With the additional oil, the engine began breathing properly, allowing them to fix the air leaks.
All this is speculation but mechanical mysteries are always intriguing.

Kerry I agree anything like you suggest is possible. Automotive mysteries are fasinating. I know it's the mystery that keeps me going or perhaps the challenge on some problems. That fuel cap off could have easily been the stimulious or decoy .

Your suggestions are not total speculations either. If he had monitored his oil level or topped it up as soon as he stopped he may have gotten away with it.

We will perhaps need a second almost identical case to occur to get any real baseline. Or is any member willing to drop his mercedes diesel oil level three quarts of oil and drive fast on the highway?

A thread like this one is not all downside if it makes people driving 20-30 year old cars check their oil level regularily. Since these cars have the potential of heavy oil leakage developing at any time they really qualify. Just by checking the oil level everytime they fuel up they will hopefully see the level dropping abnormally early enough. I am aware a lot people like myself already do check the level. I am also aware a lot of people seldom if ever check their level. .That habit can get costly enough you wish you had checked it after it is too late.

Needless to say an attendant at a service station should not be given this duty unless you like your oil level higher than it should be. Plus it might be hard to determine what they would do as a few might not know what an oil dipstick is. Or where to put the oil in.

miljohnj5 · #70 08-08-2008, 07:28 PM

I made it into town last week. I also made an appointment for my car with a forum recommended mechanic. I'll report the details so maybe this thread can be resourceful later.
In the meanwhile, I seemed to luck out with the big picture. My old Air Force friend is stationed here and he's letting me stay for cheap in his nice house, no slumming for graduate school.

He's also letting me borrow his Jeep while he's out in Texas. Getting around town in a new Rubicon is nice but I miss my car. I'll think I'll rename it Lt. Dan in memory of my cross country trip, 2,658 miles later he maybe down but he's certainly not out. "I had a destiny. I was supposed to die in the field! With honor! That was my destiny! Sorry Lt. Dan...

kerry · #71 08-08-2008, 07:39 PM

Did you have to have more work done on it or did you drive it there as it was?

miljohnj5 · #72 08-08-2008, 07:57 PM

Quote:

Originally Posted by kerry

Did you have to have more work done on it or did you drive it there as it was?

I drove it. Turbo was still working and there weren't any more issues after my (mis) adventure #2 beyond the slight ticking sound which will be looked into next week. Oil leak slowed to 1 drop per 20 seconds after running 6+ hours when I was on the road. Smoother running and idle after Lucas additive seemed to reduce blow-by and the engine temp stayed fine through the rest of Texas, New Mexico (stayed overnight) and into Arizona. Oil leak was still minimal after I drove it to the indie shop this week in 100+ heat and engine temps were fine too. The acceleration has picked up around 40-50 and the acceleration at passing speed is even higher than it used to be at 60-70 mph. Hopefully I'm not dumping fuel somewhere if it's feeding the engine excessively in order to cause the higher-than-normal speeds. I'll post facts later instead of my limited speculations.

nickofoxford · #73 08-09-2008, 03:57 AM

man im sorry to hear about that. as already said i'd try to run the engine on an alternate fuel source to rule out whether the actual fuel is contaminated and depending on what could be or is in the fuel i would keep an eye on seals and hoses down the road. if the kids put anything seal-eating in the tank that could explain the injector leak. as for the fuel door lock, check your trunk lock actuator (should be under a plastic pop-out panel). man i ripped every single door panel off and put some hours on my mity-vac to find the stupid trunk lock was dry rotted, the trunk isn't a great place for vacuum elements

just throwing that out there. hope you get this all worked out

-nick