Too Much Engine Oil

[alpineglen]

Too much oil was added at my last oil change (approx 1/2 qt/litre). Engine idles rough for a short while @ startup then smooths out. Slight rough idle at stop. Has been extremley hard on fuel ever since. I drained the oil down to half way between the add & full lines on the dipstick, no change. Will too much oil damage a crank or cam position sensor?

 

[BigSlim]

Too much oil was added at my last oil change (approx 1/2 qt/litre). Engine idles rough for a short while @ startup then smooths out. Slight rough idle at stop. Has been extremley hard on fuel ever since. I drained the oil down to half way between the add & full lines on the dipstick, no change. Will too much oil damage a crank or cam position sensor?

Alpineglan,

Adding 1/2 quart too much engine oil will not cause any measurable damage to your engine or its vital components. The excess oil that you have added will either leak out or burn off over the course of a few days. Inspect the area around the oil pan (refer to this GMC Canyon oil pan diagram) for any spillage.

If you added more than a quart of excess oil to you engine then you would have cause to be alarmed. If your oil level is high enough for the crankshaft to splash into it then this aerates the oil (translated: introduces air into the oil) which destroys the oils ability to properly lubricate the engine. This could result in bearing damage. The excess oil splashing up to the piston rings could also make it impossible for the rings to seal, which is why you might see oil billowing out of the tailpipe. This will foul your spark plugs, and possibly damage oxygen sensors/cat.

Aren't you glad that you didn't overfill it too much?

 

[alpineglen]

Thanks for the info. I let the garage (not a dealer) know about their mistake. Ever since this happened my mileage has gone to the dogs, only 240 miles/400kms per tank. No engine light, codes or stored codes. I changed the cam position actuator solenoid (after talking to a GM mechanic who also owns one), but no improvement . Any ideas?

 

[Molson02536]

Thanks for the info. I let the garage (not a dealer) know about their mistake. Ever since this happened my mileage has gone to the dogs, only 240 miles/400kms per tank. No engine light, codes or stored codes. I changed the cam position actuator solenoid (after talking to a GM mechanic who also owns one), but no improvement . Any ideas?

Try turning the ignition keys on and then pulling the ECM fuse out for a few seconds. Once the fuses are back in place, start the engine and go for a test drive. This should reset the PCM to recalibrate the engine's performance and economy.

Good luck and keep us posted.
Molson02536

 

[alpineglen]

Tried pulling the fuse with ignition like you suggested but no improvement.

 

[alpineglen]

Finally found the problem. The engine was running too cold, so I had a new thermostat installed and the mileage has improved!

 

[alpineglen]

Engine oil change had nothing to do with decreased gas mileage, just bad luck that it happened at the same time. The culprit was the engine thermostat. Replaced that annually since and the engine runs hotter, keeping the mileage up where it should be (getting 31 mpg highway).

 

[hfos]

oto much oil

My new o me 2010 Canyon SLE 2.9 4x4 had an oil change just before I bought it. Very soon after my check engine light when on with code P0017. camshaft, and crankshaft position sensor etc. I drained almost a quart, reset the code and it has not gone on since. Coincidence? Can anyone give an insight?