If you drive a car with too much oil, what could happen? - PeachParts Mercedes-Benz Forum

BullGator2020 · #1 02-17-2015, 03:52 PM

Could driving with too much oil (let's say more than 3 quarts over) cause oil to leak into the exhaust?

What are some other issues that can occur?

1993 300D 2.5 Turbo

Thanks,

W

interzonearts · #2 02-17-2015, 05:28 PM

interesting question. The only way i can think of for the oil to get into exhaust would be through the turbo. To get oil trough the exhaust valves first you'd have to have oil in the cylinder but if the oil level was high enough to reach the inside of the clinker then the engine would have really hard time turning i think.

dude99 · #3 02-17-2015, 06:16 PM

You can hydraulic the block and blow seals out, or in extreme cases, a hole in the block. As for oil in the exhaust, are you sure its oil and not just sooty water?

t walgamuth · #4 02-17-2015, 07:13 PM

Hydralock generally bends a rod or two.

dude99 · #5 02-17-2015, 09:02 PM

Quote:

Hydralock generally bends a rod or two.

I was actually referring to hydraulicing the block, when the pistons come down into the over filled oil and push it out somewhere... but hydrolock is also a possibility.

ah-kay · #6 02-17-2015, 09:17 PM

Just Google "overfill oil in engine" or something similar and there is a lot info/comments. Majority is no good.

The short answer is bad as oil can foam or blow a seal. The long answer is by how much, up to the brim? And how long the car had been driven? What size engine or oil capacity? I would say overfill by 3 quarts should not have done permanent damages as it may only be 1" above the max mark. There is too many variables in there and you might get lucky.

t walgamuth · #7 02-17-2015, 09:22 PM

Quote:

Originally Posted by dude99

I was actually referring to hydraulicing the block, when the pistons come down into the over filled oil and push it out somewhere... but hydrolock is also a possibility.

I have never heard of such a thing. hydrauulicing the block means what?

Mölyapina · #8 02-17-2015, 09:22 PM

It could promote the engine running away.

97 SL320 · #9 02-17-2015, 10:18 PM

What is the capacity of the engine? For a 5 qt system, 3 QT really isn't that much because the oil pan volume increases as the level rises ( bottom on the pan is a small sump, as you go up the area increases. )

For reference, I worked on a 90's Jaguar inline 6 with unknown history that had a supposed bad head gasket / low oil pressure / bad engine. On running the car I could tell the smoke was oil not coolant and the high level on the dipstick came from too much oil.

Piecing the list of failed parts together, the oil pressure sender failed causing the gauge to show zero oil pressure at idle and just above. Previous owner thought car needed oil and kept adding and adding and adding. . . I pulled about _4 gallons_ out of a 7 qt ish engine. The engine was pushing oil past the crankcase breather then into the intake manifold.

In the near term the engine didn't seem to suffer. While not the best thing to do, over fill is way better than underfilling.

vstech · #10 02-17-2015, 11:22 PM

Quote:

Originally Posted by t walgamuth

I have never heard of such a thing. hydrauulicing the block means what?

I think he means hydraulicing and I think he means foaming up the motor, causing a run away condition...

he is separating hydraulicing from hydra locking... so, he's not talking about bent rod syndrome...

dude99 · #11 02-17-2015, 11:25 PM

Quote:

I have never heard of such a thing. hydrauulicing the block means what?

When the crank is submerged in oil it whips it up into a frothy foam. This expands to fill the crank case. When the pistons come down normally there is an airspace, which is fine as the air can move\compress. However the oily froth does not compress, which means it is instead forced elsewhere.