Cold engine oil change?

I normally change my oil on a warm engine. Got started with other things last night and did not get to actually draining the oil while the engine was warm. It is jacked up now, belly pan off, front wheels off, and would like to not have to take it down to run it until warm, all other things being equal. I buy into the physics of warm, cycled oil holding particles in suspension better (and therefore likely draining more completely), and if opinions are such, I will take it down and run it warm. If opinions are that draining cold will be equally effective, if not simply longer, then I'll do it cold.

This is on the '05 Golf BEW (126,500 miles), thanks in advance.

kcunniff said:

I normally change my oil on a warm engine. Got started with other things last night and did not get to actually draining the oil while the engine was warm. It is jacked up now, belly pan off, front wheels off, and would like to not have to take it down to run it until warm, all other things being equal. I buy into the physics of warm, cycled oil holding particles in suspension better (and therefore likely draining more completely), and if opinions are such, I will take it down and run it warm. If opinions are that draining cold will be equally effective, if not simply longer, then I'll do it cold.
This is on the '05 Golf BEW (126,500 miles), thanks in advance.

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I also see the warm engine logic, but I like to do cold oil changes because all, or a lot more, of the oil is in the pan. Any warm engine is still going to be draining back into the pan...Mark

I like warm oil changes, especially with the heavier oils the TDI uses. You don't do it when the engine is hot, just warm. Give it plenty of time to drain as well, to make sure it gets out of all the journals and into the oil pan

Seriously?

I just read the original post to my wife, who knows almost nothing about cars. She said the EXACT same thing that I was thinking.

Why not just start the car while it's jacked up and let it run till warm?

Why you take wheels off to change the oil? ;-) I drive my car up on wooden blocks which get my engine up high enough to slide my 5 gallon oil change bucket under the pan. Oil bucket is an old metal paint bucket.

Warm oil drains back pretty fast as thin as the oil is when hot. Warm oil also drains faster than cold oil, I theorize. On one hand if you are only driving 15,000 miles a year and the engine can go 600,000 miles you might get tired of changing the oil and dispose of the car before you wear it out. On the other hand your 15,000 miles a year could be much harder on the engine than my 35,000 miles a year. Cold starts are more harmful than moderate highway speed driving.

Worry less, drive more.

roadhard1960 said:

Warm oil drains back pretty fast as thin as the oil is when hot. Warm oil also drains faster than cold oil, I theorize.

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To me, it is not a matter of draining fast, it is a matter of draining it completely. I remove the oil filter first, because I don't know how many times I have dropped a filter into a pan of old, dirty oil. I am never in a hurry, so I begin draining, go inside and relax for a while, then complete the change. I'll admit that I am not in business, so time is my own...Mark

Conrad -JSW said:

Seriously?

I just read the original post to my wife, who knows almost nothing about cars. She said the EXACT same thing that I was thinking.

Why not just start the car while it's jacked up and let it run till warm?

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I'm sure you know that it would take a good while for a TDI to get up to temp by just idling. That seems like a waste to me. Driving it I can run an errand.

roadhard1960 said:

Why you take wheels off to change the oil?

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I rotated the wheels and was going through my normal inspections.

I agree that changing oil when it is warm is the best. Like others have mentioned, not being on a time crunch makes it easier to let the oil drain for a few hours while I tend to other things (like naptime).

However, I think that in this case, you will be okay with a cold drain. Your car will forgive the transgression.

Happy driving

I typically do all oil changes on a cold engine. Less issues with touching the wrong parts and coming away with blistered skin. With the weights of most Lois these days, it's hard to imagine that the difference would be much more than a few ounces out of four and a half quarts of oil.

I know it is beating a dead horse but I add 5 quarts when doing an oil change and I am not past my full line on the dip stick. There is almost 8 ounces sitting in the oil filter housing and oil cooler.

I do agree that hot engines are painful. I sometimes loosen the oil filter to let it drain, pull the drain plug and come back a while later.

kcunniff said:

I'm sure you know that it would take a good while for a TDI to get up to temp by just idling. That seems like a waste to me. Driving it I can run an errand.

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You don't have to get it up to full operating temp, just warmed up enough so that the oil flows a bit better. But as others have stated, one cold oil change won't hurt anything.

Way back in the day, VWs didn't have oil filters, just a screen "oil strainer." It was common to run non-detergent oil. You wanted to drain the oil hot, so that as much of the sediment as possible was carried out with the draining oil.

Today, the sediments are trapped in the filter.

However, I still prefer to drain the oil when it's warm. Counter-intuitively, I want to do this so I DO NOT completely drain all the oil. Since the filter keeps the oil relatively clean, I want to restart the engine after the oil change while the bearings, cams, lifters, cylinders, etc. still have an oil flim. Yes, this is "dirty" oil, but I prefer to dilute my clean oil with a bit of dirty oil rather than risk a startup with no oil film on the critical parts and perhaps a small delay before the oil pressure builds to normal levels after the oil change.

It's a tradeoff between diluting the new oil with a bit of the old versus having an oil film on the critical parts when I start the engine and the pump has to fill the filter before actually lubricating the engine.

That's just one man's opinion...

Thanks for the input, I ended up driving it until getting to operating temperature then performing the drain and change as normal.

Still interested in gathering more opinions and experiences for future consideration, so keep 'em coming!

I prefer the warm oil change also but in the event of a cold change I just let it drain longer. Go eat lunch and then return to add new oil and filter.

I prefer the warm oil change also but in the event of a cold change I just let it drain longer. Go eat lunch and then return to add new oil and filter.

It's July... in Florida.
How cold could your oil be?

I will simply note that while having the oil warm is an aid in speed, and something could be said for getting some small stuff in suspension before draining, I will note that IMO an occasional cold oil change is almost certainly going to be of no long term consequence, and I doubt that even regular cold oil changes would make any real difference over the long run. Provided you give it enough time to drain (say a hour or more) then since diesel oil is naturally formulated to hold particles in suspension, I don't see that it would make much difference if those were fine particles of carbon, or something else. I would say if you feel uncomfortable starting it on the ramps, then pull the drain plug and walk away for awhile. Come back later and finish the job.

Just have it warm in the winter as it takes a long time to drain out when it's really cold. Here's something I didn't know: the oil and coolant temps are about the same driving around until you pull a grade. Nice to have all the temps available.