[Yarok]

There has been a lot of talk about ensuring not that the dealer does not overfill your oil, but I've had two oil changes and both time they overfilled. The first time I took it back to the dealer and this time I'm going to drain the excess oil myself.

My question is... what, exactly, is the damage caused by too much oil? Is there short/long term damage? Does the car perform differently?

Thanks!

 

[hyperion]

Just depends on how much of an overfill. If it's just above "full" probably no harm at all, and I expect thats what you are finding on a return from your Toyota dealer along with 32 pounds of air all around in your tires which is what my dealer puts in every Toyota car he services. (even when requested has been 35/33.)

 

[firepa63]

My 04 was overfilled--about 3/4 of an inch above the full mark. The only observation for me was a drop in MPG. I averaged about 5 MPG less with the overfilled crankcase.

 

[ehurtley]

Well, if an engine is severely overfilled, you can blow a head gasket, and possibly warp parts. (I had a friend do that in a mid 90s Honda Civic, he put 3L into a car that already had 2L in it, with a max of 2L; the engine was so damaged that it had to be replaced..)

 

[mrv]

US TSB EG050-04. December 20, 2004. ENGINE OIL SPECIFICATIONS. 2001-2005 Prius. (Incorrect engine oil viscosity or improper fill level may result in a M.I.L. "ON" condition (most common Diagnostic Trouble Code P3191 "Engine does not start"). Use SAE 5W-30 API grade SL "Energy Conserving" oil and use proper fill quantity.)

http://autos.groups.yahoo.com/group/toy ... 050-04.gif
http://autos.groups.yahoo.com/group/toy ... 050-04.gif
or http://www.alldata.com/tsb/Toyota/11035 ... _EG050-04/

 

[calinkus]

My 2005 Prius had 1/4" above the full mark-from the dealer new.

 

[Guest]

My 2005 Prius had 1/4" above the full mark-from the dealer new.

Mine, too. So the factory apparently doesn't get this right, either.

Another reason to do oil changes yourself. And if you use fully synthetic oil, you can run up higher mileage intervals between changes.

 

[hyperion]

And obviously the 1/4" overfill is not at all harmfull and probably occurs because filler "rounds things out" American oil pans should have been designed 1/2" deeper.. to account for U.S. quarts.