Oil Change on a Cold Engine

Status
Not open for further replies.
Joined
Jun 10, 2010
Messages
1,231
Location
Duval Co. Jax FL, USA
The more i think about it, maybe the Muck that has always been in my Engine or in the Pan was finally shwing itself (also Oil level discrepancy) was there because we did the OC on a COLD Engine.

I have 16oz. MMO left, i will probably put that into my engine also my last 6 oz. SeaFoam, as the OC was very recent, and be SURE to chnage the Oil Hot/Warm next time!

Any other Perils, or unexpected behavior, from a "Cold" OC?
 
That muck at the bottom of your pan won't come out without a spatula. However, yes, do it hot next time and why not run MMO for a bit to shake some gunk loose.

I always think of seafoam more as a gas additive and it shouldn't get into your oil. Incidental foam done on a piston ring soak should come out immediately with a followup oil change.
 
When you say MUCK, have you done an UOA or pressure test to confirm your head gaskets are OK? I was ging to ask if you see any gas bubbles in the oF tank, but i recall thuis engin e uses the German-syle pressurised translucent reservoir. That 2.5 V engine should run pretty clean with a healthy PCV system. Its a nice engine.
 
I try to do my oil changes with a hot engine so that the oil flows out easier and the filter comes off a tad easier because everything is warm.
 
I run the car to warm it up, let it cool a few minutes and change the oil. Hot oil flows better and what ever the filter misses is in supsension.
 
I too drain my oil warm/hot but, really just out of habit. I think long ago when straight 30 wts were used it made a great deal of difference but, not today with the 5 wt. My typical draing ambient temp is 60-90 F and the oil flows quit freely at those temps.
 
I change oil cold sometimes. I don't see it as being a big deal and like he said if there is alot of muck/debris in the pan where did it come from?
 
The ability of any solvent to dissolve solute is going to be dependent upon temperature.

The hotter the oil is, the more muck you will remove, period.
 
Originally Posted By: Eddie
I too drain my oil warm/hot but, really just out of habit. I think long ago when straight 30 wts were used it made a great deal of difference but, not today with the 5 wt. My typical draing ambient temp is 60-90 F and the oil flows quit freely at those temps.


You are correct. I keep reading about hot oil changes, but cold changes where the car has sat for a time has more oil in the pan. More oil and with more contaminants. The oil was hot when you shut down the motor. Your hot oil which everyone claims hold more containments in suspension is still hot as it ends in the pan.....with the contaminants

Today's oil flows freely at air temps, with the possible exception of up north in winter. We read all the stuff about cold starts, pour points oil etc, yet when it comes to oil changes, the air temp oil doesn't hold enough containments in suspension or flow freely enough out of the pan to carry any containments that may have settled a bit?

I do it either way as time and conditions allow.
 
Cold or hot, The junk should be in the filter or in suspension. It was almost 100 deg when I did my last OC, and I did it cold. Havent done a cold OC in a LONG time. The used 5w-30 oil seemed to take longer to get out of the pan than when hot. You are prob looking at 90cSt v 10cSt hot. The last few light drippies and streams seemed to last forever!
wink.gif
 
Last edited:
Originally Posted By: Steve S
Where did all this muck come from in the first place, been wondering?


Steve! Hi!
34.gif


It has either:

1) Always been there, never showing itself due to Hot Oil Changes..
27.gif

2) Appeared, and been Enhanced by, a Can of Moly (Thought it was Not an O.D. as per Can Dosing instructions,)
3) The result of MMOs previous, and "No Oil Changes" before i got the car.
27.gif


In any case, it looked Very Funky. I would give anything to go back in time with a Camera and take a picture of that drained Oil, and video of the muck from Fill Hole it was low on Oil too.. However, even though they first thought it was "Water in the Oil" "Milkshake," Further examination, and me looking very closely and shining a flashlight on the Pan and sticking my Finger in it to look for Water (which had a "Caramel Swirl" in it, same color as what was coming out of Fill Hole, slightly mud-like) THIS WAS ON ENGINE THAT SAT FOR 3 HOURS so it was "Cold" .. determined it was likely Moly-related.

I cannot conclusively say if my engine is Mucked up (sludgy) or not. Now the 5W-50 is in there, and all seems to be well. I still get 50-wt. High Pressure its less with 40, (30 will be consumed, ive posted about this)

Im going to use Syntec 5W-40 next time. No more ARX plans for me, thanks. MMO may still get use, a slow, deliberate cleaning, topping off with MMO. Seems to be the only thing thats safe, unless i give Kroil/Kreen a shot before OC 500 miels before and change on HOT Engine!

After all, thats the first time i actually had SEEN anything like that. All other times, on warm/hot engine, it flowed out Fine, and on the Black side.

No HG issues with my car. Though i checked it out, and my Coolant could use changed, due to age. Coolant is Green, not Oil colored. Plus, no other HG symptoms, thanks. Want to keep it that way, car never Overheats.
lol.gif


Moly Moly Moly. Seems to have done Good AND Bad.
thumbsup2.gif


My engine runs Fine, too. Other things on it cause Hesitation, and it got the quickest Piston Soak ever.. One Hour with SeaFoam.
 
If you added moly to the muck, the muck will have moly in it.
Blame the bad neighborhood, not the nice old lady that is visiting!
 
I actually plan my oil changes right after a trip home from work, a good 50 miles. Just got to be careful of that cat. Got some nice burns from it. When my dad showed me how to change oil he always did it hot, so I do too.
 
Originally Posted By: defektes
I actually plan my oil changes right after a trip home from work, a good 50 miles. Just got to be careful of that cat. Got some nice burns from it. When my dad showed me how to change oil he always did it hot, so I do too.


So, is it worth it???

Did my first cold change that I can remember last oil change? I let it drain until the stream starts sticking to the pan and going everywhere like I always have and ended up not having to add a pint the first 1500 miles like I usually have to.


That was a great oil change. Not too much sweating from all the additional heat (95 ambient). The oil filter was a breeze to handle and I wasnt so worried about oil hitting my arm when removing the plug. The car was ran about one minute to move onto the driveway.
 
Originally Posted By: tenderloin

You are correct. I keep reading about hot oil changes, but cold changes where the car has sat for a time has more oil in the pan. More oil and with more contaminants. The oil was hot when you shut down the motor. Your hot oil which everyone claims hold more containments in suspension is still hot as it ends in the pan.....with the contaminants

Today's oil flows freely at air temps, with the possible exception of up north in winter. We read all the stuff about cold starts, pour points oil etc, yet when it comes to oil changes, the air temp oil doesn't hold enough containments in suspension or flow freely enough out of the pan to carry any containments that may have settled a bit?

I do it either way as time and conditions allow.


When its oil change time, I'll frequently put one of my vehicles up on ramps on a Friday night when I'm done with the car for the day and leave it overnight. Wake up in the morning and pull the plug and let it drain. Sometimes I'll even pull the plug that night and let it drain overnight. I always end up getting at least 1/4+ more of a quart out of the engine doing this (seen when I empty my oil pan into one of the used oil jugs I've got lying around).
 
I do it warm after it has cooled for awhile. I burn myself all the time on hot oil changes. I dont particularly feel the need to do the same on my own stuff.
 
Originally Posted By: buickman50401
When its oil change time, I'll frequently put one of my vehicles up on ramps on a Friday night when I'm done with the car for the day and leave it overnight. Wake up in the morning and pull the plug and let it drain. Sometimes I'll even pull the plug that night and let it drain overnight. I always end up getting at least 1/4+ more of a quart out of the engine doing this (seen when I empty my oil pan into one of the used oil jugs I've got lying around).


^ this. I experienced this and get 1/4 to 1/2 more oil out.
 
Status
Not open for further replies.
Back
Top