Little or NO power after bottoming out suspension- 1981 300SD - PeachParts Mercedes-Benz Forum

funola · #1 03-12-2013, 12:49 AM

Quote:

Originally Posted by ROLLGUY

I am not sure exactly the speed he was driving, but it could have been as much as 70. He was traveling on a frontage road, and most cars travel around 60 when I drive on it. He thought he had a fuel filter problem, so he had a friend bring a set of filters, and he changed them on the side of the road. The primer pump was bad, so I imagine that is why they could not get it started, and towed it back home. Yes the dented oil pan crushed the rubber piece, and broke it at the seam where it attaches to the pickup. I did not bother to replace it, as it seemed to work without the piece on the bottom (I did not have a replacement anyway).

So Brad did not try to start the engine immediately after stalling and waited til after new fuel filters were installed before trying to start the engine?

ROLLGUY · #2 03-12-2013, 02:32 AM

Quote:

Originally Posted by funola

So Brad did not try to start the engine immediately after stalling and waited til after new fuel filters were installed before trying to start the engine?

He did try to start it, but it would not start. That is when he thought the filters were clogged, so they were changed. A combination of the battery being drained from trying to start it, and it being an old battery, the car was towed home and the battery was put on a charger. I think he noticed the big dent in the oil pan the next day, so he called me to help. All the time we were diagnosing and replacing parts, the charger was on the battery. That being said, I don't know if the engine being hard to start was because of the extra friction (still a theory), or just an old battery. After getting it running finally, it did and does fire right up with the same battery.

JimSmith · #3 03-12-2013, 10:56 AM

Quote:

Originally Posted by ROLLGUY

He did try to start it, but it would not start. That is when he thought the filters were clogged, so they were changed. A combination of the battery being drained from trying to start it, and it being an old battery, the car was towed home and the battery was put on a charger. I think he noticed the big dent in the oil pan the next day, so he called me to help. All the time we were diagnosing and replacing parts, the charger was on the battery. That being said, I don't know if the engine being hard to start was because of the extra friction (still a theory), or just an old battery. After getting it running finally, it did and does fire right up with the same battery.

I think the question is aimed at finding out if the starter motor turned the crankshaft when the attempt to start the engine immediately after it shut off following the bottoming out event. The implied understanding is that the engine was seized, and the starter motor did not have the juice to break it loose. If the engine rotated with the starter motor there is no real reason to suspect the engine seized.

Jim

ROLLGUY · #4 03-14-2013, 02:31 PM

Today I talked with Bruce (Brad's car is parked at his shop), who is helping with this problem.
Bruce is the guy that has also been helping Brad with his car (towing and repair theories).
Bruce is no dummy when it comes to engines (Diesel especially), as he has been working on them most of his adult life.
All 4 of the vehicles he has now are Diesels (2-300SD'S, 2- Ford trucks).

I respect and value his opinions and knowledge when trying to figure out the cause of this problem, and how to fix it.
Bruce told me that he talked to Brad, and he remembers the oil pressure used to be much higher.
It was at 3 when cold (idling), and went down to about 2 after warmed up.

Of course it pegged the needle when revved up.
He (Bruce) started the car yesterday to check it out, and noticed that the oil pressure was at about 1.5 when idling.

After running the engine to warm it up, the oil pressure was barely above 0 at idle, and would only get up to about 2 at full throttle (approx 1,800-2,000 RPM).
He checked the oil level, and it was fine.

He also was going to remove the belts to check if there was any friction caused by the accessories, but instead he used a mechanic's stethoscope to see if he could hear any bad bearings or anything that might cause external friction.
He did not hear any abnormal noises from the water pump, alternator, PS pump or A/C compressor.
If there was friction caused by an accessory, there would be a slipping belt, or a noise, or at least some indication that there was a problem.
He did not notice anything out of the ordinary.

He has thought this whole ordeal through, and he believes that the cause of the lack of power and engine speed, is in fact from oil starvation when the pan was dented when bottoming out the suspension.

The observances of the oil pressure getting less the longer the engine has ran since the original problem occurred, points to something inside the engine causing internal friction (spun main bearing etc.).

Thinking back on all the work/tests I have done (all in vain I might add), have me believing the same thing.

I think if I/he was to start the engine again and run if for a long time, it would soon seize up.

Bruce also seems to think it is making more internal noise than before.

To change the subject, Brad got a job the other day.
It seems that he may have enough money to buy a car soon.
Bruce has an extra 300SD that he might be willing to sell Brad, but it needs some minor repair to be road worthy.
If that happens, I might help out by buying Brad's 300SD.
I have another friend (Mike) that has the almost exact car with a bad trans.

If this all happens, the engine and trans will get pulled, and the trans will go in Mikes car, and I will dissect the engine from Brad's car to find out if internal friction has caused this problem.

Either way, I don't think Brad's car will ever drive on the road again.....

Rich

Brian Carlton · #5 03-14-2013, 03:32 PM

The underlying curiosoity that cannot be easily explained is how the engine failed to get oil through the pump during the event (which was momentary) but, somehow, managed to fix itself so that it now is able to pump oil and build pressure immediately after the event.

Could this "bump" that bottomed out the suspension actually have been a situation where the vehicle went airbore and all the oil in the pan decided to head upward when the vehicle came down?

That's the only possible explanation that I can fathom..............the story of "bottoming the suspension" isn't completely truthful and we've been on a chase because of it.

whunter · #6 03-14-2013, 04:40 PM

Quote:

Originally Posted by Brian Carlton

The underlying curiosoity that cannot be easily explained is how the engine failed to get oil through the pump during the event (which was momentary) but, somehow, managed to fix itself so that it now is able to pump oil and build pressure immediately after the event.

Could this "bump" that bottomed out the suspension actually have been a situation where the vehicle went airbore and all the oil in the pan decided to head upward when the vehicle came down?

That's the only possible explanation that I can fathom..............the story of "bottoming the suspension" isn't completely truthful and we've been on a chase because of it.

Call me, and I can explain this in detail you will find clear.

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funola · #7 03-14-2013, 06:24 PM

Quote:

Originally Posted by whunter

Call me, and I can explain this in detail you will find clear.

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Should everyone who wants to know call you?

I'd still like to know immediately after engine stalled and it failed to start, a detailed description of what happened.

1. Did it crank at normal speed and did not start?

2. Did it crank slowly and laboriously and did not start?

3. Did it seize and did not turn at all, with just a clunk from the starter?

I'd like to see a pic of the dented oil pan and the "crushed the rubber piece on the bottom". Sadly, the only pic that's been posted is the set of rebuilt injectors that was installed.

I thought we were going to see a video of it starting and running. What happened to that?

funola · #8 03-14-2013, 06:31 PM

Quote:

Originally Posted by Brian Carlton

The underlying curiosoity that cannot be easily explained is how the engine failed to get oil through the pump during the event (which was momentary) but, somehow, managed to fix itself so that it now is able to pump oil and build pressure immediately after the event.

Could this "bump" that bottomed out the suspension actually have been a situation where the vehicle went airbore and all the oil in the pan decided to head upward when the vehicle came down?

That's the only possible explanation that I can fathom..............the story of "bottoming the suspension" isn't completely truthful and we've been on a chase because of it.

Maybe it has something to do with the "crushed rubber piece on the bottom"? If it is an inlet to the oil pump, maybe it was partially or totally obstructed by the dented oil pan?

whunter · #9 03-14-2013, 07:32 PM

Quote:

Originally Posted by funola

Maybe it has something to do with the "crushed rubber piece on the bottom"? If it is an inlet to the oil pump, maybe it was partially or totally obstructed by the dented oil pan?

Exactly...
This is rubber.
Compress the oil pan enough, and it becomes a SEAL between the oil pickup head and oil pan face = it will vacuum seal in place, and starve the engine bearings = running metal to metal at high speed = damaging ALL bearing surfaces = increasing friction/temperature.

If you are lucky/unlucky everything expands so fast the engine shuts down from raw friction, before the babbitt bearing is more than "seriously surface damaged" = pull the engine, clean the crankshaft/bearing journals, replace all bearings.

IMO:
The critical question is engine crankshaft/block journal damage, 75/25 chance this engine can be saved, if it is not run any more before repair.

Thankfully this is not common with a crushed oil pan, usually (90%) the rubber, pan or oil pump pickup tube break = clear oil flow.

My rule of thumb: If it ran like this (higher than idle) longer than 5 seconds, the bearings are toast.

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The OLD broken part drooping from the oil pickup tube.

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The OLD broken part removed = you can see the rip hanging open.

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The NEW and OLD broken part side by side.

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The NEW replacement part.

help? 1984 300sd rubber oil pickup broken

http://www.peachparts.com/shopforum/diesel-discussion/147821-gruesome-617-engine-pics-dont-look-if-you-have-weak-stomach.html

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