I noticed a substantial difference in the oil color when removing the engine. Some was "like new" from the engine, the tank oil was black. Can anyone explain the difference?
Thanks
Full Version: Oil Circulation/ stock 914 6
I'm no expert but I would say you have a circulation problem. Maybe all the crap just lingers in the oil tank?
Don't know why you have a difference and I won't claim to be an expert either.
Roughly the oil circulation on stock 914-6 is as follows:
From the bottom of the tank into the suction side of the pressure pump.
From the pressure pump thru engine case to the engine mounted oil thermostat.
If hot: from the thermostat to the engine mounted oil cooler and on to the main oil galley and on to bearings & such
If cold: from the thermostat to the main oil galley and on to bearings & such
From the bearings & such down into the bottom of the engine case where the scavenge side of the oil pump picks up the oil and pumps it back to the oil tank.
At the oil tank it goes thru the oil filter before dumping back into the tank where it can head back to the engine.
If there is and external oil cooler there is an external thermostat between the exit of the scavenge pump and the oil tank where the oil can be routed to the cooler and back where hot.
The oil from the tank goes straight into the engine with out being filtered , so what ever the oil in the tank looks like should be what the oil in the engine looks like.
If this is a car that has been sitting for a long period of time, maybe the oil in the tank got contaminated.
Jim
Roughly the oil circulation on stock 914-6 is as follows:
From the bottom of the tank into the suction side of the pressure pump.
From the pressure pump thru engine case to the engine mounted oil thermostat.
If hot: from the thermostat to the engine mounted oil cooler and on to the main oil galley and on to bearings & such
If cold: from the thermostat to the main oil galley and on to bearings & such
From the bearings & such down into the bottom of the engine case where the scavenge side of the oil pump picks up the oil and pumps it back to the oil tank.
At the oil tank it goes thru the oil filter before dumping back into the tank where it can head back to the engine.
If there is and external oil cooler there is an external thermostat between the exit of the scavenge pump and the oil tank where the oil can be routed to the cooler and back where hot.
The oil from the tank goes straight into the engine with out being filtered , so what ever the oil in the tank looks like should be what the oil in the engine looks like.
If this is a car that has been sitting for a long period of time, maybe the oil in the tank got contaminated.
Jim
Thanks Jim.
I puzzled, the circulation system keep the oil equal. The car has sat for a couple of years due to health issues. The last drive I developed an oil leak from return tubes causing 3 qts. of oil to be added.
Gene
Don't know why you have a difference and I won't claim to be an expert either.
Roughly the oil circulation on stock 914-6 is as follows:
From the bottom of the tank into the suction side of the pressure pump.
From the pressure pump thru engine case to the engine mounted oil thermostat.
If hot: from the thermostat to the engine mounted oil cooler and on to the main oil galley and on to bearings & such
If cold: from the thermostat to the main oil galley and on to bearings & such
From the bearings & such down into the bottom of the engine case where the scavenge side of the oil pump picks up the oil and pumps it back to the oil tank.
At the oil tank it goes thru the oil filter before dumping back into the tank where it can head back to the engine.
If there is and external oil cooler there is an external thermostat between the exit of the scavenge pump and the oil tank where the oil can be routed to the cooler and back where hot.
The oil from the tank goes straight into the engine with out being filtered , so what ever the oil in the tank looks like should be what the oil in the engine looks like.
If this is a car that has been sitting for a long period of time, maybe the oil in the tank got contaminated.
Jim
I puzzled, the circulation system keep the oil equal. The car has sat for a couple of years due to health issues. The last drive I developed an oil leak from return tubes causing 3 qts. of oil to be added.
Gene
QUOTE(jcd914 @ Oct 7 2012, 10:30 PM) 
Don't know why you have a difference and I won't claim to be an expert either.
Roughly the oil circulation on stock 914-6 is as follows:
From the bottom of the tank into the suction side of the pressure pump.
From the pressure pump thru engine case to the engine mounted oil thermostat.
If hot: from the thermostat to the engine mounted oil cooler and on to the main oil galley and on to bearings & such
If cold: from the thermostat to the main oil galley and on to bearings & such
From the bearings & such down into the bottom of the engine case where the scavenge side of the oil pump picks up the oil and pumps it back to the oil tank.
At the oil tank it goes thru the oil filter before dumping back into the tank where it can head back to the engine.
If there is and external oil cooler there is an external thermostat between the exit of the scavenge pump and the oil tank where the oil can be routed to the cooler and back where hot.
The oil from the tank goes straight into the engine with out being filtered , so what ever the oil in the tank looks like should be what the oil in the engine looks like.
If this is a car that has been sitting for a long period of time, maybe the oil in the tank got contaminated.
Jim
Where is that drawing from?
When I bought my car I took a ride with Willem Modderman to give me the run down on my car. He told me to make sure that you always listen for the bubble coming from the oil tank and you will know that all is working right (circulation). You can hear the oil percolate in the tank when the car gets warm. I am often asked what the hell is that bubbling when people ride in my car. Bubble Bubble Bubble. Do you get the bubbling on your car?
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