JohnJL

I was just heading out, armed with Robin's DIY pages, when I realized I haven't seen any comments about warming up the engine before changing. No notes in the archive either. Is this necessary/preferred?

Thanks all,
John

jstahmann

I've always heard it 'helps the old oil drain out easier'. Not sure if it's offically a recommended practice, but I usually drive a bit to warm up the oil before an oil change.

amfp

I always warm engine before changing oil, it seems to blend any dirt on bottom of tanks to flow out - rather than sitting on the bottom. Also to me filters come off easier.

os993

Can't hurt, but beware that when doing a full 993 oil-change (both filters), you need to get in there, and hot parts and hot oil around is not great when you're under the car.

Warm, I guess, would be ideal, but doing a cold oil change seems to be just fine as well.

993Maineiac

Mine is cold-never seems to be a problem getting all of the oil out. It's enough of a PIA getting the middle filter off without hot parts to contend with-just my opinion.

Al

GabiOsz

I guess you could drain it while its hot and wait for it to cool down before changing the oil filters. This is what my mechanic did on the last service, as soon as I took the car in he drained the tank and left it over night to continue the service.

kkim

I would think warm/hot would be preferred, but if this is your first time doing this, perhaps it might be better to try it cold and see how it goes first. That's what I did when I did my oil change for the first time a few months ago.

Hope you're prepared with a good oil wrench and have done your homework by reading past posts on the subject.

Good luck. Sure gives you a good feeling once you get it done.

chris walrod

Since I dont have to have it done in an hour like a shop would need to, I typically change it cold. My thinking is all the junk is settled to the bottom of the tank and crankcase, so thats the first to be washed out. Just my thinking

kev

For the record, the 993 shop manual "officially" recommends warming the car beforehand.

Like others, I have changed it cold.

Fred, Long Island

Cold change has one advantge. If there is a buildup of condensation (water) from a number of short trips, it will be the first element out of the drains. It is visible as you pull your hand and the plug away in the futile attempt to keep your fingers clean.

JohnJL

For the archive, cold (30 degrees) was fine. Oil flowed out slowly, but no issues.

I wonder why you'd want it warm...seems like if it's been sitting for a while any metal/other heavy particles would rest on the bottom and get flushed out first....?

thanks everyone...

milrad

You are all assuming that what is on the bottom comes out first. This would be true if the bottom of the tank and crankcase had steeply angled walls ending in an opening which matched the shape of the cross section of the container, only smaller. This is known as a "mass flow" bin bottom, as in First In, First Out. Unfortunately, we just have a hole from where the plug comes out. This is a "funnel flow" bin bottom. It means what's on top drops down through the hole, causing the rest of the material to "cave" in on itself as the level lowers. This is Last In, First Out. It's easier to draw than to explain, I guess :-). Pull the drain on your sink sometime to see a crude example.

Jason

JohnJL

Ah so. Thanks.

ca993twin

The downside of changing your oil when it's cold? You don't get to experience hot oil running into your armpit. This is part of the Porsche ownership experience.

993Maineiac

C'mon Steve, last oil change I made the requisit blood sacrifice-boiling in oil would be an unnecessary add on.

Al