Run Engine or Not Prior to Oil Change?

[reubenray]

Should I or should I not?

[rk911]

Originally Posted by reubenray

Should I or should I not?

kind of a vague question. are you asking if you should change the oil immediately after taking possession; how often you should change the oil, if there is a 'break-in' period during which you shouldn't exceed a certain RPM limit or something else???

I change engine oil twice a year or every 5K miles whichever comes first. that's more aggressive than the mfg. recommends but that's ok. when we bought new in the fall of 2015 we were told that Winnebago does not have or recommend a 'break-in' period and our owner's manual confirms that.

do whatever makes you feel comfortable. changing engine oil in, IMO, cheap insurance. check your owner's manual for any recommendation on a 'break-in' period and for the recommended service intervals.

good luck.

[twinboat]

Run it until hot and then change it.

Gets all of the particles that settled out, back in suspension, within the oil.

[affreeman]

Sometimes I do. Sometimes I don't.

[lanerd]

You know I've heard it done both ways. Personally, I don't due to the fact that I don't like to start the engine without driving it for quite a while and my Mh sets for up to six months. In addition, since it has set for so long, all the oil has dripped down into the pan so when I drain it, I get more out. I do leave the plug open for about a 1/2 hour prior to putting it back in and putting in new oil/filter.

Changing the oil once a year with a new filter and only driving about 5000 miles per year, the oil is still clean when I change it.

Ron

[D Lindy]

If you do drain it when hot you'll have to take it out and run it till it gets up to operating temps, not just let it idle in the driveway.

[vtwinwilly]

Usually I do. Something I learned in Auto Shop way back in high school. The idea was, running the engine would do 2 things...

1) stir up any contaminants or sediment making them free floating in the oil, and ...
2) make the oil flow more freely so you get more out, more easily (more complete change).

This was Auto Shop in New Jersey, so who knows if it's true!

It's not like a religious experience for me. If I don't have time or just forget, I figure that a cold oil change is better than no change at all.

[Pusherman]

Originally Posted by reubenray

Should I or should I not?

Yes! As others have mentioned, it stirs up the contaminants to be drained out and makes it drain better.

Con is you don't want the oil so hot as it will burn you when draining.

[Crazeee1]

Originally Posted by reubenray

Should I or should I not?

I always run my engines up to operating temp before oil changes. Flows more easily.

[soonerdave]

I don't think either way is wrong, most important thing is changing the oil on a regular basis.

Changing your oil when hot because it stirs up contamination and let's it drain with the oil, think that one is false. The job of the oil filter is to catch and contain crud in your oil, if you get crud from the oil pan you aren't changing the oil often enough. Hot oil will burn, this is definitely true. Hot oil drains faster, true. Years ago when filters weren't as efficient changing oil when hot made more sense, don't think it's true today.

Only drawback to changing the oil when cold is it takes longer because the viscosity is higher. Remove the drain plug and then go do something else while the oil is draining. With a cold engine you don't have to worry about hot manifolds or exhaust.

Again, regular oil changes are the key to engine longevity!

[cyclone429]

Originally Posted by twinboat

Run it until hot and then change it.

Gets all of the particles that settled out, back in suspension, within the oil.

Actually there is a procedure, this is due to the fact particles become "encapsulated" within the oil molecule- we know is as suspended solids. Some very expensive equipment manufacturers requires oil changes to take place at operating temperature, for this very reason to remove the suspended solids.

Engine oil has a few jobs to do, it washes away debris from cylinder walls, engine bearings and allows the transportation of this to get to the oil filter to be separated or knocked out of suspension- liquid /solid separation. Secondly, the engine oil removes heat away from high friction points such as rod bearings, camshaft lobes, crank journals to control thermodynamics or heat control.

Regards, Marv

[TeJay]

The two letters on oil containers HD stand for High Detergent. That means as cyclone429 stated the dirt (metal particles) are carried away because it's suspended in the oil.

Some of us are old enough to remember the gas station attendant asking our Dads, "Do you want Detergent or Non-Detergent oil?"

The ND oil did not suspend the dirt particles.

I am not schooled in that science so I don't know for sure if getting it hot before draining the oil will actually remove more dirt particles? It may but after all these years changing oil both hot and cold the oil almost always came out dirty.

As far as I'm concerned, well it's really not a big concern. Most of us drive primarily at highway speeds. Engines operated at those speeds are contaminated the least. We also have very good oils and changing it at least close to the recommended mileages the oil is still not to dirty.

[Stuart W]

Originally Posted by soonerdave

I don't think either way is wrong, most important thing is changing the oil on a regular basis.

Changing your oil when hot because it stirs up contamination and let's it drain with the oil, think that one is false. The job of the oil filter is to catch and contain crud in your oil, if you get crud from the oil pan you aren't changing the oil often enough. Hot oil will burn, this is definitely true. Hot oil drains faster, true. Years ago when filters weren't as efficient changing oil when hot made more sense, don't think it's true today.

Only drawback to changing the oil when cold is it takes longer because the viscosity is higher. Remove the drain plug and then go do something else while the oil is draining. With a cold engine you don't have to worry about hot manifolds or exhaust.

Again, regular oil changes are the key to engine longevity!

Soonerdave you read my mind on this one..and to add when I drain it cold I will pull the drain plug and let it set for hours. When I do this it always takes more oil to reach the fill mark on the dipstick.

[Old Scout]

Ok I get it run the engine to get contaminants back in suspension but now you have oil circulated back thru out the engine. So now you have to wait for the oil to settle again. So when is the sweet spot where all of the oil has returned to the pan yet warm enough to have retained the contaminants? Frankly, if you change the oil and filter on a regular basis, I doubt if it really makes much difference whether if drained hot or cold--IMHO......
PS--what I do know is working around/under a hot engine can be a pain--literally.