Ok so this is what happened. I accidentally put an extra 1/2 quart of oil in my 2009 Chevy HHR SS. It is not the original engine. I had the original engine replaced recently with the ZZ Performance LDK Long block which is the exact replacement for a Buick Regal GS. This engine calls for 6.3 quarts of oil. So that I am guessing means roughly six and a half quarts of oil. There is around 7 quarts of oil in the engine right now. My question is, will the extra half a quart of oil hurt my new engine?

 

If it were me I would put the car on the level and check the oil level on the dipstick.
If I shows what you feel is high I would pull the drain plug and let about a quart out in a clean pan.
Put the drain plug back in and wait 10 minutes then add back from what you drained to make it come out at the full mark. Be sure to give some time after you add each time for it to get in to the pan before dipping the stick.

Done.... Now you can sleep at night.

Silverfox

 

What does the dipstick indicate? GM says anywhere between the lines is ok. I'm guessing the additional volume is on the bottom, so the old dipstick should work.

You could just loosen the drain and get a oily arm or get one of those "oil change pumps" that pumps the oil out through the dipstick chute (used in marine apps).

I don't think a half quart is really going to harm much.

 

Half a quart isn't much , you should be fine, just remember the correct amount for next oil change and beyond!

 

Sure, it should be fine, but... you just spent a pile of money on this new engine, how hard is it to drain the oil and refill it to the proper level? Me, I wouldn't run it with too much oil.

 

x2 what RJ says. Being .7 of a quart too much is kinda pushing it. Note it is .7 of a quart, not HALF a quart. It may or may not do any long term harm, but then again why not do it right in the first place?

Tip: just cause the specs says it uses 6.3 quarts, don't just dump 6.3 quarts in and call it quits. One has to actually check the level as that last quart is added to ensure it is not under or over filled.

 

There are 2 main ill effects from an overfill:
1. flooding the crank seals. Level above the bottom point of the seals.
2. added resistance to the crankshaft. Level above the splashers on the counter weights of the crank.

 

I believe the LDK has a windage tray to avoid splash up to the crankshaft counter weights.
So, what does the dipstick show?? How much over filled , 1/4 inch? 1/2 inch?
When do you plan on next oil change?
Is this the first break in oil run, I'd change it at 1,500 miles tops. Especially in a turbo engine.

 

I doubt anything serious will happen. As others said, learn from it, and move on. It's 10% extra. It will probably get blown out through the PCV system.

I used to lose more than that when I had one of them flat 4 engines. Heck, I could blow 1/2 to 3/4 of a quart through the PCV during one autocross day, with a co-driver. I would purposely over-fill by 0.5 quart to prevent oil starvation by day's end.

The car is past 200k and still running fine. No oil loss. It's not mine, but the buyer is lovin' it...

 

If overfill is great enough oil will foam, counter weight is like an eggbeater. Aeration will cause lack of lube to parts due to the air that's now in the oil.