Too Much Oil?
Thread Starter
Instructor
Joined: Sep 2003
Posts: 130
Likes: 1
From: Florida Treasure Coast
Too Much Oil?
Any danger in adding too much oil? My car took 7.5 quarts to get the fill line on this oil change. Should I be watching the pressure or anything? The manual says to add an extra quart when racing or competitive driving, but to remove it afterwards, so I think I'm ok. Don't want to cause any damage. 
Team Owner
Joined: May 2001
Posts: 87,315
Likes: 1,585
From: Western NY
Originally Posted by Dave68
6.5 is perfect, 7 is a bit much, and 7.5 would make me uneasy. Remember, a full crankcase reads halfway up the crosshatch.
When I changed my oil this past spring, I got the car full warmed up, so the "winter oil" would flow out readily, jacked the rear higher than the front, so al the oil would drain, then let it drain for about an hour. Mine took a little over 7 qts. to refill. Naturally, this included the additional oil that the filter contains...
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
Originally Posted by l80ous
When you Yanks say Quarts do you mean Litres?
Why isn't "full" at the top of the crosshatch? It sounds misleading.
By the way, the factory dip stick marking is misleading. 6.5 quarts does NOT cause the oil mark to reach the top of the cross hatch pattern.
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Le Mans Master
Joined: Feb 2002
Posts: 6,937
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From: Waldorf MD
There are previous threads on this. Appearently the dipstick was changed in later years, so 6.5 quarts don't show as full. On my 1998, 6.5 quarts comes to top of cross hatch.
By the way, raising the rear only drains another 2 ounces of oil. Hardly worth it, but I do it anyway.
By the way, raising the rear only drains another 2 ounces of oil. Hardly worth it, but I do it anyway.
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
Originally Posted by rws.1
The dealership has always filled my '01 to the full mark on the cross hatches....
There are previous threads on this. Appearently the dipstick was changed in later years, so 6.5 quarts don't show as full. On my 1998, 6.5 quarts comes to top of cross hatch.
Pro
Joined: Apr 2005
Posts: 666
Likes: 5
From: Mt. Pleasant SC
Yes, that is too much oil unless you are racing. Believe the 6.5 qts that your owner's manual calls for. I can't comment on the apparent problem with the later C5's dipstick reading because I have a 2000 and 6.5 qts brings me exactly to the top of the cross hatch each and every time.
Racer
Joined: Jul 2004
Posts: 474
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From: Pa
Originally Posted by Beezvette
7.5 is a lot. Most people put in 6.5 or 7. I put in 7 and it fills it about 2/3 of the way up the cross hatch. I would not put 7.5 in.
I have a 04 and 7 quarts 2/3 of the way up the cross hatch.
Advanced
Joined: Sep 2005
Posts: 73
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From: Great Mills MD
I find this interesting. I bought my Z about a month ago and checked the oil after I got it home (only had 1500 miles on the current oil change). When I checked it, it read just above the lover mark on the dip stick so I added a quart to bring it up the top of the fill line.... So, is this safe or do I need to drain a little oil?? I've owned a lot of cars in my life and this is the first time I have ever heard that "full" is not the top line on the dip stick.
Team Owner
Joined: May 2004
Posts: 26,345
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From: SoCal
Originally Posted by Dave68
1 litre = 1.056 quarts
Dave Hill has stated in the past that after a full drain (10 minutes), oil refill is 6.5 quarts. Of course if you jack the rear 6 inches higher than the front and let the oil drain overnight, you may be able to fit in 7 quarts but 6.5 is the average refill volume.
By the way, the factory dip stick marking is misleading. 6.5 quarts does NOT cause the oil mark to reach the top of the cross hatch pattern.
Dave Hill has stated in the past that after a full drain (10 minutes), oil refill is 6.5 quarts. Of course if you jack the rear 6 inches higher than the front and let the oil drain overnight, you may be able to fit in 7 quarts but 6.5 is the average refill volume.
By the way, the factory dip stick marking is misleading. 6.5 quarts does NOT cause the oil mark to reach the top of the cross hatch pattern.
I change my oil every 3-4K miles. I now have over 50K miles on the car. EVERY time I put in 6.5 quarts.... and EVERY time it is at the top of the hash marks. This on a 2004.
What do you think......
DH
Race Director
Joined: Aug 2000
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i had a 2000 coupe and presently have a 04z06. both of these c5's take (or took) 6.75 quarts to fill (top of the hatch pattern, so mid hatch pattern would be about right @ 6.5 qts). i always raise the back up a little higher than the front, and let drain for 20 or 30 minutes. when i took delivery of my 2000 coupe, the oil level was somewhere around 1 inch above the hatch pattern - so much for dealer prep 
JoeC
JoeC
