#1  
Old 06-10-2021, 04:41 PM
track73 track73 is offline
Ultimate Warrior
 
Join Date: Nov 2006
Location: Munster In
Posts: 1,504
Default oil change

I have always changed oil after the engine was at operating temperature. But I was wondering why. If the engine in question was at operating temp when it was shut down and hasn't been run for a day or 2 and the ambient temp is in the 80's, wouldn't the oil have been all drained to the lowest point anyway. Since I'm retired I don't put many miles on my daily driver. Why nor just drain the oil for an hour with out heating it up?

__________________
1979 Trans Am WS-6 .030 455 zero decked
flat pistons
96 heads with SS valves
041 cam with Rhoads lifters 1.65 rockers
RPM rods
800 Cliffs Q Jet on Holley Street Dominator
ST-10 4 speed (3.42 first)
w 2.73 rear gear

__________________________________________________ _______________________________

469th TFS Korat Thailand 1968-69 F-4E Muzzle 2
  #2  
Old 06-10-2021, 04:57 PM
HoneyHush HoneyHush is offline
Senior Member
 
Join Date: Mar 2014
Location: Florence,Ky.
Posts: 246
Default

I always change my oil cold. You don’t burn yourself, any water that’s in the oil is on the bottom, and as much oil has drained to the pan as going to.

  #3  
Old 06-10-2021, 05:04 PM
b-man's Avatar
b-man b-man is offline
Moderator
 
Join Date: Sep 2002
Location: Sunny So Cal
Posts: 16,410
Default

The contaminants in the oil are in suspension when it’s hot just after shut down, the contaminants will drain out easier and more completely this way. Many owners manuals for older cars prescribe this method, many didn’t have oil filters so they asked you to follow that procedure.

When cold it all settles and sticks to the bottom of the pan, you get less of the contaminants out this way.

Do whatever you wish.

__________________
1964 Tempest Coupe LS3/4L70E/3.42
1964 Le Mans Convertible 421 HO/TH350/2.56
2002 WS6 Convertible LS1/4L60E/3.23
  #4  
Old 06-10-2021, 05:05 PM
mgarblik mgarblik is offline
Ultimate Warrior
 
Join Date: Mar 2005
Posts: 6,035
Default

If you service your car often and don't have very dirty oil or sludge build-up inside, it really doesn't matter much. The argument always is that warm oil flows much easier and more of the old oil will come out when you drain it. That's true. Also the contaminates are more likely to be in suspension in the oil if it's drained hot just after running. True again. But if you use a quality oil filter and change the oil often how much of a real big deal is it? None really. 10 minute fast lubes began really pushing the "always change the oil hot" deal because that's what they do. You drive your car to them blazing hot off the interstate and they change the hot oil for you in 10 minutes.

  #5  
Old 06-10-2021, 05:18 PM
padgett's Avatar
padgett padgett is offline
Senior Chief
 
Join Date: May 2021
Posts: 467
Default

I always change my oil warm, not hard to do when usually is above 70F year round.

Besides hot vs cool flow for a 5w-30 or 0w-40 synthetic is minimal anyway.

__________________
Orlando - Where rust must be imported.
Web Site


  #6  
Old 06-10-2021, 05:46 PM
ZeGermanHam's Avatar
ZeGermanHam ZeGermanHam is offline
Ultimate Warrior
 
Join Date: Nov 2016
Location: Seattle, WA
Posts: 1,924
Default

Personally, I don't think it makes an ounce of difference either way. The most important thing is just performing routine oil changes, period. I can see the arguments for both approaches. If you drain the oil after the engine has been warmed up, the contaminants may indeed be suspended more evenly in the oil, but less of that oil is in the oil pan to be drained. In contrast, if you wait overnight, most of the oil is down in the pan, but contaminant suspension is less.

I think it's a wash either way. Just change your oil and filter regularly and enjoy the ride.

__________________

1966 Pontiac GTO (restoration thread)
1998 BMW 328is (track rat)
2023 Subaru Crosstrek Limited (daily)
View my photos: Caught in the Wild
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:15 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017