I read this in Road & Track a while ago in the technical correspondance when a person wrote in and asked if it were OK to turn the engine over a few turns (not start) when the oil is completely derained out to get all the excess dirty oil out and they replied that it was!

What do you guys think? Sound risky?

 

IMO...BAD idea

 

VQ can handle it.. go ahead and do it

 

I don't think thats really necessary. If your engine is really that dirty and needs a cleanin that bad, it's probably time for a complete engine overhaul anyways....or a new car.

OH, and to add, it probably won't hurt the engine as you're just turning it, most likely with some residue oil still in it.

 

thats like driving without oil... engine idle @ 700rpm... engine parts are moving @ 700rpm thats bad

 

VQ can take anything

 

No, not turn the car on, but 'cranking' the engine for a couple turns, not 700 turns.

 

if your engine is that dirty..run a engine flush through it.

 

NO! In order to get all the oil out, rev the engine really high!

 

damn yo, you'd probably get some other engine parts out at the same time too!

 

But the oil is really brown. Wont that hurt the engine???

 

This would be the quickest way to destroy your engine.

 

The thing is...how are you going to go about turning the engine ONLY, without starting it and causing damage????

Leave and let be, I say. It ain't broke yet.

 

disconnect a few of the ign coils and the car will never start.
u can turn that starter all day and it won't fire.

 

Not until it's between medium dark brown and light dark black.....

 

what if i like it well done? dark black?

 

Makes me wonder 'where the hell do they hire their technical editors from?'. I wonder if these numnuts have ever worked on a car or anything mechanical. Unpressurized residual oil does NOT lubricate cam/crank bearings.

Filter/drainplug/gravity/hot oil.....is all you need to get almost all the oil out. If your oil is so dirty that you are trying to get out every last drop, then why the hell would you bother changing it in the first place Just drive vehicle into the ground and trade it in for a new car.

Sure, disconnect your coils. Fill those cylinders with fuel so that when you refill your oil, the gasoline leaks past the rings and saturates your brand new oil. Why not add a pint of gasoline to your oil if you want to ruin it this quickly

Can't wait until some monkeybrain runs his battery dead with no oil and then writes R&T saying that he killed his battery, had to jump start it, and that there was a ton of bearing noise right before the motor seized. I smell a misinformation lawsuit brewing.

 

My dad told me he used to do this when he used to change his oil. It wont hurt it if you crank it real quick, but if the engine fires then you could do some damage.

 

You drain out about 4+ quarts, almost 5 quarts. You replace it with fresh oil and a new filter.

How much oil is still in there after you drain it? Is it worth wearing out the starter for an ounce of oil? If the engine starts, is it worth wearing out the moving parts?

Why even bother disconnecting coils, etc?

Run the engine to normal operating temperature, shut the engine off, drain immediately, hot oil is less viscous, flows out better. Worry not about the small qty of oil left in the engine. It won't make much of a difference.

 

I drove without oil once...

...bent the crankshaft

- M

 

Not worth the risk for a simple 15 minute oil change in my opinion.
Do it with your 500,000 mile tuneup. Thats when you'll KNOW your engine is probably gunked up with bad stuff.

 

I must say...most well said. I agree totally.

 

There is no risk if you crank it, but dont start it. I dont do this method just in case the car starts up

 

Yep, instant bearing wear. Plus all that material will float through your engine until its filtered out.

Just because Dad does it, doesn't make it right. The starter can turn the engine over at several hundred rpm. Without pressure, you will get wear. Remember that the engine is still cycling. There is serious load on the engine during compression. What is your definition of 'real quick'? What do you expect to get out of 'real quick'?

There IS risk. When rebuilding engines, I use assembly grease on all friction surfaces. And, in some engines, the oil pump will be primed. The oil filter is also FILLED prior to installing(usually messy on most cars). This will prevent some of the 'cold/first start wear' on the engine. I also fill the oil filter at every filter change. This eliminates the 'first start clatter' from the engine after an oil/filter change.
The wear is caused by engine CRANKING/STARTING with NO oil pressure.

Let me repeat myself. Residual oil will NOT lubricate the bearings in your engine. You need oil PRESSURE to prevent wear. If oil was so great at lubricating bearings, then use it to lube your wheel bearings/races.....Now you know why we use grease. Its not economical to provide oil PRESSURE & oil volume to the wheel bearings & races.

And again, DO NOT CRANK THE ENGINE WITHOUT OIL.

If gravity/hot-oil/filter & plug removal does not remove enough oil, and you are so frigging ****-retentive or obsessive compulsive, then purchase a shopvac/bissel wetdry vacuum cleaner and VACUUM that last ounce of oil from your pan. No need to touch the starter with drain plug removed.

There would be no market for accumulators/crank scrapers/prelubers/windage trays/pans with baffles/catch cans.....if maintaining oil pressure wasn't so important.
http://www.prelub.com/
http://www.pre-luber.com/
http://www.prelube.com/
http://www.firstlube.com/
http://www.autoenginelube.com/index.htm
http://www.masterlube.net/features.asp
http://www.thinkauto.com/accumulators.htm
http://home.planet.nl/~brink494/accu_e.htm
http://www.minesupply.com/Lubrication.htm

My experience with 'pathetic mechanics(not persons but the art of)' is that people who do this are the same ones that never top off their oil and also never change it frequently enough. Then, they run to the dealer for new engines under warranty and/or slander the mfg for making $hitty engines, poor dealer customer service,...... They never blame the fact that they were 3 quarts low & forgot to change the oil/filter in 50k miles. And if/when they did, they made sure to crank the oil to get every last drop out.

 

Is that like feeling the difference an oil change gives your car?