Car Accident: Roof Damage, Engine Failure?

Hello everyone!

The day before yesterday, a good acquaintance had an accident in his Jeep Rubicon, manufactured in 2012, with a 2.8-liter common rail diesel engine from VM Motori.
He fell asleep while driving and hit a tree stump on the side of the road at low speed. The car rolled over the stump and eventually came to rest on its roof. Fortunately, he was not injured, but there was significant damage to the vehicle's body.
According to him, the engine was still running when he regained consciousness after a brief shock – although he hadn't turned it off.
It is certainly possible that a high gear was engaged just before the accident, and that the speed at the time of tipping was so low that the engine stalled (best-case scenario). Otherwise, some other event would have caused the engine to stop (e.g., fuel shortage?).

The vehicle is now parked in a storage area - there was no attempt to start it. We would like to know what kind of damage an overturned vehicle can cause to the engine, and what course of action would be most appropriate. Before we try to start the engine, we manually rotated it a few times.
'A mechanic mentioned that an overturned engine could be damaged by the engine oil, which, when the engine is tilted, can put pressure on the piston crowns. According to him, it's possible that oil might not drain quickly enough from between the piston crown and the crankshaft, potentially causing a collision with the piston. This could result in mechanical damage such as broken oil scraper rings. These wouldn't be noticeable when turning the engine by hand, but would cause significant damage to the cylinder wall after starting.'

It should be noted that the car has special equipment and is therefore priced accordingly.
Is it worth disassembling the engine to avoid potential damage after starting?

Sure, here's the translation of the text from German to English:

'Furthermore:'

What causes an engine to stall when it rotates 180 degrees?

Are damages in the valve control system possible (e.g., hydraulic blockage of hydraulic lifters)?

Is the statement about oil leakage between the piston skirt and crankshaft accurate, or what could actually be broken in that area?

What other damages should we expect, or what experience do you have with this?

Thank you in advance!

Manuel.

Hello, Curious George.

If the engine continues to run after being overturned, it will seize due to a lack of lubrication.
If there is no oil present at the pump or at the lowest point of the oil pan, then nothing will be lubricated.
Try turning the engine over manually. If that works without any problems, I would check for any visible damage and then attempt to start the engine.

Best regards,

The engine was shut off by the airbag control unit before the rollover occurred (due to a crash trigger).

Hello,

As far as I know, the Jeep also has a crash sensor or sensors that cut off the fuel supply in the event of an accident or rollover.
The engine could have been switched off for that reason, and it doesn't necessarily mean it was defective or seized.

Check the air filter/box and intake manifold for engine oil, which may have leaked in from above the cylinder head gasket.
It would then be sucked in and burned (leading to uncontrolled high RPMs in a diesel engine). If there's nothing there, I would – as klahaui already said – simply try starting it.

Here's a tip in case nothing happens when you try to start something:
The interruption is usually static and can typically only be disabled via OBD/a diagnostic tester.


Regards, Mpire.

edit: someone was faster.

Quote:

It would then be sucked in and burned (uncontrolled high-speed rotation in a diesel engine)

.

If that happens and he starts to get extremely agitated, the only thing you can do is quickly close his airways. So, take precautions.

Possibly, you might unscrew the glow plugs beforehand and try to start it manually, if it can be turned over by hand.

First, remove the glow plugs and turn them manually. Then, use the starter until no more oil comes out of the combustion chambers. Refill the engine oil, remove the air filter (it will be oily), and then you can try starting it.

I used to be able to get almost any overturned vehicle running again, including fixing its engine.

Hello!

Tomorrow the car will be picked up. Then, the glow plugs will be removed, and the engine will be cranked manually or with a starter. Possibly, the air hoses will be disconnected to check for oil leaks on the pavement.

'Thank you!'

Manuel.

Hello,

I was logged in as Manuel26 and wanted to provide a quick update.

The vehicle was transported from the accident site to the garage some time ago using a trailer.
As you described, the preparation was carried out there.
There was a large amount of engine oil in the intake air path (it entered through the connection between the valve cover and the air filter).

We also let the engine run for a while using only the starter motor – we prevented it from starting by disconnecting the plugs from the injectors. There's probably a more professional way to do this.

The engine started up without any problems afterwards!

Best regards, Manuel.

Hello.

Great Thank you for the feedback.


Regards, Mpire.