Oil in Water

[Wessel]

They oil may be still as black as normal, but is the level dropping?

My thoughts...... The less you drive it the better. The oil sticks to every internal part of the engine and cooling system. If not cleaned out properly the oil will eventually cause the rubber hoses to deteriorate and go soft, after which they will start to blow.
Whatever type of oil mixes with coolant it always emulsifies and looks like what you have there in varying shades, so the colour is no guide to where its come from.
As others have said, its hard to imagine how falling off the jack could create such a fault.

The driver side wheel was taken off. The driver side brake disk fell about 2 foot on concrete. The jack and the stand was also somewhere underneath. The engine cover below showed that it pushed in a few inches. The coincidence is just too big that the fall had nothing to do with it. I checked it before and the next day after it had oil in the expansion tank. From everything I have read my feeling is that the oil cooler or transmission cooler cracked with the fall causing the mixing of water and oil.

 

[noonboots]

I'm not familiar with the model but presumably the transmission oil cooler is a pipe that passes through the radiator on the cold side. The fall would have to have caused this pipe to fracture inside the radiator somehow. Anything is possible I suppose. If the examiner sees damage to the pipes you will be in with a chance.
The engine oil cooler on the other hand is a very common failure on every type of engine and can happen at any time.
Water rarely gets into the engine oil because the pressure in the oil system is greater than the cooling system pressure. The transmission oil in the cooler pipes is not under such high pressure, I've seen water in older type auto boxes.

 

[umblecumbuz]

... Water rarely gets into the engine oil because the pressure in the oil system is greater than the cooling system pressure. The transmission oil in the cooler pipes is not under such high pressure, I've seen water in older type auto boxes.

Lift the oil filler cap when the engine is running, and it will be evident that the bulk of the engine oil is at normal atmospheric pressure. There is plenty of opportunity for water to emulsify with the engine oil.

The cooling system, on the other hand, is always at much higher pressure while the engine is running.

 

[noonboots]

Lift the oil filler cap when the engine is running, and it will be evident that the bulk of the engine oil is at normal atmospheric pressure. There is plenty of opportunity for water to emulsify with the engine oil.

The cooling system, on the other hand, is always at much higher pressure while the engine is running.

The oil pressure is typically 60 psi +.The cooling system around 18psi.

 

[umblecumbuz]

The oil pressure is typically 60 psi +.The cooling system around 18psi.

You are ignoring the fundamental difference between the two systems.

The entire coolant system is pressurised. That is why the coolant system has a pressure cap. Try removing it while the engine is running and there will be a severe loss of pressure! There is no part of the system at normal atmospheric pressure.

In contrast, the oil filler cap can be removed for inspection while the engine is running, without any pressure loss. This is because there is only a small part of the oil circulation system that is pressurised, while the major part of the system is at normal atmospheric pressure.

 

[noonboots]

You are ignoring the fundamental difference between the two systems.

The entire coolant system is pressurised. That is why the coolant system has a pressure cap. Try removing it while the engine is running and there will be a severe loss of pressure! There is no part of the system at normal atmospheric pressure.

In contrast, the oil filler cap can be removed for inspection while the engine is running, without any pressure loss. This is because there is only a small part of the oil circulation system that is pressurised, while the major part of the system is at normal atmospheric pressure.

At what point in an engine does water under pressure come into contact with oil at atmospheric pressure? It would have to in order for coolant to get into the oil. In the oil cooler (more accurately called the heat exchanger because its main purpose is to get the oil to temperature more quickly then keep it there) the oil is under pressure far greater than the coolant passing around the core.
All irrelevant to the fact the CLS fell off the jack.
Finis.

 

[umblecumbuz]

As said, it could be atf getting into the coolant because the accident somehow may have fractured the seal within the heat exchanger radiator. This seems more likely than engine oil getting into the coolant. If so, the engine oil will be unaffected and water will not contaminate it. Easy to monitor.

... In the oil cooler (more accurately called the heat exchanger because its main purpose is to get the oil to temperature more quickly then keep it there) the oil is under pressure far greater than the coolant passing around the core.
All irrelevant to the fact the CLS fell off the jack. Finis.

Oil pressure within an engine is not a constant. There is a direct relationship between pipe bore and pressure. Maximum oil pressure is confined to the small bore drillings typically serving the crankshaft and camshaft. Other areas are also fed with pressurised oil - such as a turbo or supercharger where fitted - but at a lower pressure.

The oil feed pipework to a coolant/engine oil heat exchanger, where fitted, is at a lower pressure still, having larger bore feed, return and internal pipework. So engine oil flowing through a coolant heat exchanger is nowhere near the maximum pressure of the pump - thank goodness!