Flush before oil and filter change

[williamsmotowerx]

Why do you think it's a good idea to warm engine up before oil change?

I prefer to change oil cold after a nights rest. Everything that can had a chance to settle. Warming it up isn't going to loosen anything that's already stuck in the crevices.

[lefty o]

Why do you think it's a good idea to warm engine up before oil change?

I prefer to change oil cold after a nights rest. Everything that can had a chance to settle. Warming it up isn't going to loosen anything that's already stuck in the crevices.

because the crap has settled and stuck to the bottom of the pan and doesnt come out when drained. warming it up gets it in suspension allowing the crap to drain.

[williamsmotowerx]

So you're saying the sediments in pan will stay in pan on a cold change?

What about the suspended junk that's now dispersed throughout the engine on a warm change? That all comes out?

[lefty o]

So you're saying the sediments in pan will stay in pan on a cold change?

What about the suspended junk that's now dispersed throughout the engine on a warm change? That all comes out?

most of it will come out. if you do it cold, almost none of it will come out, and it will keep moving thru the engine.

[engineguyBill]

Cold oil will cling to walls and inside crevices moreso than warm/hot oil will. Warm oil will flow much more freely and bring with it the majority of crud that is inside the engine.

[williamsmotowerx]

The last time you shut it off, the oil was hot... and it had a chance to completely drain into pan.

When you run it for 15 minutes before oil change, it's now dispersed everywhere, and won't have that long time frame to settle into pan.

I'll say if you're going to do a 8 hour oil change, drive car into garage and drain overnight is best, but a quick change I still think cold is best.

[Tuner]

Why do you think it's a good idea to warm engine up before oil change?

I prefer to change oil cold after a nights rest. Everything that can had a chance to settle. Warming it up isn't going to loosen anything that's already stuck in the crevices.

because the crap has settled and stuck to the bottom of the pan and doesnt come out when drained. warming it up gets it in suspension allowing the crap to drain.

Let it sit overnight and heat the pan and oil with a magnetic electric heater or an electric paint stripper heat gun or a 500 watt halide light. Let it drain a good long while and then heat the bottom of the pan with a paint stripper heat gun. That might be the best way to drain the oil from one that has been sitting a long time.

[peejay]

Why do you think it's a good idea to warm engine up before oil change?

I prefer to change oil cold after a nights rest. Everything that can had a chance to settle. Warming it up isn't going to loosen anything that's already stuck in the crevices.

because the crap has settled and stuck to the bottom of the pan and doesnt come out when drained. warming it up gets it in suspension allowing the crap to drain.

If there's enough "stuff" in the pan that it is settling out, you don't need an oil change, you need an overhaul.

[pdq67]

About the dizzy cap and cleaning it with starter fluid.

I made darn sure to check it for fumes before I put the cap back on the dizzy because I knew that I could blow the dizzy up.

I waited something like a 1/2 hour or so all the while fanning the opened cap and dizzy to make sure there wasn't any starter fluid fumes around.

Like I said, I would use MMO to flush a sludged engine now-a-days.

pdq67

[BOOT]

The last oil pan I pulled had a layer of sludge in the sump like I've see before and read of others with similar exp after using break in lubes or additives. The sludge did such a good job of trapping fragments before entering the pump pick-up from a part failure awhile back that I kinda wanted to smear grease or something back in the sump.

[RDY4WAR]

Why do you think it's a good idea to warm engine up before oil change?

I prefer to change oil cold after a nights rest. Everything that can had a chance to settle. Warming it up isn't going to loosen anything that's already stuck in the crevices.

Think of cooking oil in a pan. If you let it sit overnight and try to drain it cold, it won't come out. If you dump it while the pan is still hot, it'll drain. Sludge works the same way.

[MadBill]

Yeah, if you dump it while it's hot, it firms up in your drain instead..

[peejay]

Like I said, I would use MMO to flush a sludged engine now-a-days.

MMO smells nicer, but I've had great luck desludging an engine with the cheapest ATF that the parts store had. Five quarts in the engine and change every 500-1000mi until the filters stop looking like a block of charcoal when you cut them open. Then go back to using actual motor oil, but doing the mid oil change top-off with ATF instead of motor oil, if it's burning any.

[pdq67]

Years ago, back when I had my 2000 Metro, 3-banger commuter corn-popper, a neighbor gave me 8 or 9 old quart cans of Ford Type F ATF just to get rid of it.

I added a can of it at gas fill-up until the stuff was gone. Worked great, but once my car hiccupped and belched a big cloud of smoke, then went right on down the road fine.

I think I topped that tank off instead of pouring it in at the start of my fill-up was all. Didn't get it mixed in good sort a thing. Say a quart to 9 gallons of gasoline...

pdq67

[user-23911]

Flushing has never seemed like a good idea to me.

We see lots of badly maintained ex japan vehicles with deposits stuck inside the engine.
When you use additives to do a flush, it loosens them up, they don't come loose straight away but come loose later, end up blocking the oil strainer, then they come into the workshop with low oil pressure.


So if you want to change the oil, change it hot, don't use any additives.