CWhaley

Really this practice is a hold over from the old straight weight oils of our youths... The older 20 - 30 - 40 or 50 weights would not drain down very well from the valve train area after sitting in colder temps to the oil pans of the classic US Iron! So, service techs and shade tree mechanics started the "Warm the oil" practice. Does warm oil carry or mix the contamination better then cold oil? Well, I do not have nor seen any data to support that... Yet, it might help.

These days a multi-grade syn oil will drain equally well cold (NOT FRIGID!) or warm. In the end it really is a personal practice that each does for themselves.

LVDell

Thanks everybody for the input!

So, I'll ask one follow up then to the heated oil question. Is there a difference of just letting the car idle for several minutes to get up to temp after sitting for some time rather than driving it around?

My car has been on the lift for several weeks now (since the weekend before Thanksgiving) with no wheels installed since the powdercoater is backed up. Figured I'd get the oil change knocked out while I'm waiting

Macster

From an oil change point of view I can't see any difference of any significance. The oil gets hot (warm anyhow) and the oil doesn't care if the heat comes from the engine idling or from the engine working to move the car about on the road for a while.

I don't have the luxury of having a place where I can let the car sit either backed up on ramps or (must be heaven...) on a lift until I can get around to changing the oil. If I did, I might be tempted to move the car into position and then some time later (maybe much later, a day later for instance) change the oil. At which time I'd just let the engine idle a bit to get the oil warm. In fact, given I've changed the oil several times just after driving the car 30+ miles to where I can change the oil (at the office) and changed the oil blazing hot doing the oil change with the oil warm vs. hot sounds ok to me.

Sincerely,

Macster.

LVDell

Thanks for the reply Mac

Michael-Dallas

The longer it takes for your engine to reach operating temp, the longer it runs in a rich condition (the ecu will do this to get the cats up to temp asap). This may contribute to fuel dilution in the oil, which may increase oil consumption, lower oil viscosity, and/or lower oxidation stability.

For your situation, I wouldn't worry about it. Unless I did that on a daily basis. But even still, it's nothing that a nice, long cruise on the highway can't fix.

If you want more opinions, then you may want to search or post on bobistheoilguy.com.

Michael.

adam_

Years ago I attempted to change the oil in an air cooled VW.

It was 5 below zero, Fahrenheit, in the shed.

When I took the drain out, nothing... so I took off the 6 nuts and that round plate that held the oil strainer. Nothing, had to pry it out. Then slowly a blob began to bulge downwards, eventually plopping into the pan below. It was really quite strange to see this liquid acting like tar...

After two hours not much happened. Buttoned it up- So I got two cans of oil, heated them on the stove, put it in the car. Figured to do it next time warmed up!

Generally I do it warm, not "full operating temp".

A

LVDell

Holy crap! That site gave me a headache

Dudley

I like to change my oil hot. No good reason except it flows better. I would use a double set of vinyl gloves to prevent burning my hands when I removed the drain plug. I have since gone to oil drain valves and the whole process is much easier/safer. I run a hose from the valve to my collection container.
http://www.quickoildrainvalve.com/
Of course, a few people are skeptical. They worry about quick change valves opening unexpectedly but it has not been my experience.