Hi folks. I haven't posted in a month or so, things got busy. But I have a new question. A few months ago the Chevy dealer replaced my engine after the camshaft bearings self destructed and left metal particles all through my oil. The new engine has run OK the only problem I have noticed was a 2-3 MPG loss in gas milage. However today when I changed the oil for the first time in the new engine, I found they had put between 8-9 quarts in. I know too much oil is bad. My question is how bad and what should I look for in damage this gross overfill could have caused.

 

Replaced the engine a few months ago? So when you've been checking your oil regularly,you didn't notice it was overfilled? If it didn't blow some out the seals or gaskets you are probable OK. An overfilled crankcase will take more power to turn the internal parts:hence a loss in efficiency.
In other words, your gas mileage should increase and you will likely notice a little more giddy up in your car.
AND: Check your oil regularly!!!!

 

First of all I do check it regularly. But I look for it to be low not high. One would assume the new engine would be installed with the proper amount and since I didn't ad any, I didn't notice the overfill on the stick. Your post doesn't make any sense. How does a "a loss in efficiency" cause "your gas mileage should increase and you will likely notice a little more giddy up in your car". There are no noticeable external leaks, but it would be hard to tell internal damage.

Does anybody else have USEFUL information on my original post?

 

To much oil will make the crankshaft have to drag througt the hige oil. less power less MPG. ECT.

 

Chances are you wouldn't get internal damage from to much oil.

Question though.... Did you smell the old oil? My thought is maybe there was fuel in it...... It would be very odd for a shop to put that much oil in there.... very odd indeed. Now that you have the proper amount keep your eye on it and see if it increases.


And on your questioning firemangeorge's "loss in efficiency" comment, re read what he said as it makes sense. Too much oil will cause a parasitic drag on the engine which is a loss in efficiency.... now that you have the proper amount of oil "your gas mileage should increase and you will likely notice a little more giddy up in your car".

 

Fire is saying that once you have the CORRECT volumn of oil in your engine that you will gain power and milage since the engine will no longer be being bogged down by the extra oil.

As for how it got that full it is could be that the new engine was delivered with oil in it and the tech did not check the dipstick before and after. But like Fire said if there are no visible leaks or signs of blow-by at the exhaust tip then you are probably OK.

 

Sorry you misunderstood my post. I should have inserted "now that you changed your oil and have the correct amount................"
By the way,if you check your oil regularly,don't just look to see if its low. An overfull crankcase can be a sign of internal problems(such as a cracked block,cylinder head etc.) In your case it appears to just be a problem caused by the dealer.
Later, George

 

#1) NEVER assume things are "supposed" to be right.. Check & make sure.

Over Full Oil is like trying to run in a swimming pool.. Really slows ya down.

A new engine is generally tight, & until broke-in, can experience lower gas mileage.. Which should improve with miles & break-in..

(as previously stated) Since you are not externally leaking, you might be OK..

But I'd be keeping an eye on the hot oil level, should read right on the high mark of Full..

Also keep an eye on the Anti-freeze reservior, make sure that level is not going down..

 

I do appriciate the help. You bring up a couple of interesting points I hadn't thought of. I agree it is very odd for a reputable shop to overfill this much, which is why I didn't look for an overfill on the dipstick. But I hadn't thought of other fluids increasing the volume of oil. I know water is not getting in the oil as this produces a easy to see change in the color of the oil. The oil does have a slight fuel oder, however if half of what came out of the oil pan is fuel shouldn't the fuel oder be pretty strong? How would that much fuel get into the oil? I am concerned about the possibility of fuel in the oil.

As for firemangeorge's post. I understand how the extra oil would cause loss in efficiency and power. But there was not a noticable loss of power. I thought at first the drop in MPG was due to the new engine being tight. I misunderstood the second part since I just changed the oil today and haven't had a chance to see any improvement.

 

New tight motor will have a lower mpg while breaking in...And the overoil will definitly drag down the crank rotating.