Warm the engine driving or in the driveway?
 

Just wondering what was better, to warm the engine idling in the driveway OR to gently drive it until it gets to normal operating temp? Please fill me in.

Driving ....

gentle driving till warm, that's what the manual states or something like that.

Driving. Do a search, there's several threads on the subject.

turn on engine, put on belts, drop top, play with radio / nav / HVAC, check mirrors, slowly engage 1st / reverse, go. Prob good idea to let it idle at least 30s before pulling out IMHO.

Drive! 1,000,000,000 %

Endless disussions about this topic on all kinds of forums etc etc.

Driving gently. Short shift. I don't exceed 3K rpm until the engine is warm.

Somewhere I read that holding a hairdryer over the engine for a few minutes before driving works great .

i run mine sitting until the rpm's drop (out of cold cycle) and go no higher than 3500 until it's warm.

I believe this is correct only when used in conjecture with putting your keys in the freezer before starting the car.

Wow!!! Thanks for the input. I have been doing it all wrong all these years. I just hope no one wants to race me just after I pull out of my driveway. :)

Manual says drive the car immediately after starting. Don't apply full throttle, don't exceed 80% throttle, and don't exceed 4,000rpms, until the car reaches operating temperature...then you can drive it however you want.

Well Mr. Shecky Green, back when we used to have winter we installed plenty of these.



http://986forum.com/forums/uploads01...1344443852.jpg


I sheared off a shift pin on an X19 that sat one week on the shore of Ontario, it was standing still warmed up when it happened, that's how viscous the gear fluid got.

I usually let idle for 20-30 seconds then bring rpms up to 2500 for 5 seconds or so before taking off. If I don't bring rpms up first, it surges and lurches on first take off.

Driving immediately also warms up the transmission.

New York, eh? I can tell you live in a sub-tropical climate as you only have one cord coming out of the grill. Up here we'd have dual block heaters, a battery blanket, and an interior warmer, and we'd still have to put a pan of hot coals under the oil pan for 15 minutes and spray ether into the air intake before starting it.

Howling winds, deep snow, freezing temperatures... and when we get outside it's even worse! :D

The object of the game is to minimize the load on the driveline until it is at operating temperature. How in the hell anyone can think driving is less of a load than idling where you start it is beyond me. :confused:

That's what I was always told. Why operate something that's not at least out of the cold cycle? I usually let mine run for a few minutes when cold, even in the dead of summer, before i take off.

Yet Porsche, in the owner's manual, specifically states that you should not let the car sit and idle when you start it and that you should immediately drive off. There must be some reason for them to make a point of saying that.

Is there any scientific basis for the 2500rpm number that has been posted a number of times? Just to be clear we are running modern engines, with modern synthetic oils (hopefully)... I can see no logical or scientific reason to stay under 2500 RPM. If the system has oil pressure, then there should be no metal to metal contact. Certainly full throttle or Red line ops are a no-no until the fluids are warm, because that may generate oil pressures that are higher than factory parameters. Also, in extreme temps, dissimilar metals contract and expand at different rates. Metal to Metal interference form this phenomenon is highly unlikely, but is still something that we should keep in mind.

2500, 3000, Idle...whatever. The factory says 4K is the limit cold and there is likely some scientific reason for that...other than someone on an internet forum said it once and 25 people repeated it.:p

hah! you mean everything on the internet isn't true?

my procedure:
1. open garage door
2. insert key and turn to on, until oil check is done (or chime stops, whichever occurs first)
3. start engine
4. pull out of garage
5. drive away hoping the garage door closed
6. drive to the highway onramp, 1.2 miles from the house
7. resist the urge to have fun for another 4 or 5 miles
8. usually fail

I think item #6 is the problem causing item #8 to fail..
You need to move, you live too close to the on ramp...lol:)

#5 is funny! I would change that one. Once or twice I hit the remote twice, leaving the garage open all day, facing the street, inviting anyone to rob me. Now I wait until it's fully closed before pulling away. So I guess I do Idle for 1 Minute or so.

Ummm....because Porsche says so, and they made the car.
Do you not have an owners manual? I'll take their word for it. ;)

I think the point is that idling the engine is doing exactly jack for the drivetrain and its fluids. Idling til warm may make one think that the car is ready for hard driving, when in truth this would be extremely rough on the drivetrain. Gentle driving until warm ensures that everything is ready for high rpm driving.
JM2C

The problem isn't about the load on the engine while idling. Engines don't run as efficiently or cleanly at idle, so it can lead to excessive combustion byproducts in the oil.

Shadrach, you answered your own question. The reason to limit RPM's while warming up is because all of the engine components haven't warmed up, so internal tolerances won't be correct. It's not just a question of having some oil flowing. As far as the 2500 RPM number ( I usually hear 3000 ), I think that's derived from experience and common sense. You can feel it, 4000 it getting to the area I would consider high RPM.

I did not say there was no reason to limit RPM, What I said was that I have scene "0" scientific evidence to support the 2500RPM number. You're right, it's not just question of having oil flowing. It's a questing of having oil pressure within the specified parameters. Too low and parts don't get adequate lubrication - too high and seals get blown. The latter is likely a bigger concern. Cold, viscous, oil + High RPM = High pressure. High pressure + cold seals = the propensity for a leak.
As far as tolerance and interference issues under normal conditions, my experience is that it's muchado about nothing with water cooled engines. Where oil temp is an issue is how it relates oil pressure. Many people have tried to pass off many old wives tails as coming from "experience and common sense."

I don't care if someone limits their RPM to 2500RPM until all the gauges are in the middle, it certainly is not going to hurt anything...what's mildly annoying is the people throwing out a hard number like there is some sort of science behind it. There's not as far as I can see, but I'm open to learning... I do believe that Porsche (imperfect as they've been through 986/996/987 lines knows something about engines and would not set a limit at 4K unless there was a reason to. BMW is the same, Some of the M cars had computer controlled red-lines depending on temp, but nothing as ridiculous as 2500.

Did I miss something? The only mention in this thread of 2500 was my post, and I just said that I rev it to 2500 for a few seconds before take off to smooth out throttle response. It's a little jerky on first take off if I don't. Probably should clean the maf and throttle body.

Not directed specifically at you. ;) It's been echoed as gospel both here and other places. I've also heard it stated in person. When I ask why or where the info came from, I've never gotten anything remotely close to a solid answer.

I agree. The reason they say that is to minimize emissions by warming the catalytic converters as fast as possible, after all Porsche has to warranty emissions parts for 8 years. Also vehicles get very low MPG while motionless.

Yep, also idling the car while stone cold tends to load up the cats with rich mixture carbon. Then the car runs lousy and the cats fail prematurely. Just get in and drive.
:cheers:

Yes I do have a owners manual & I have read every word in it at least twice.
It also says to change oil every 15,000 miles with Mobil 1 0w-40. Ummmm..... I assume you follow this also.
Ever watch a professional race team warmup a car for hitting the track?
KN3D

Aced my smog test yesterday, 102,000 miles on my original cats.
I prefer replacing cats over engines.

I guess we have both seen good success using different warmup techniques (102K on original motor and cats) so it really doesn't matter much, at least in SoCal. Ultimately it is your car and your $$ so do what you feel is best.
:cheers:

Yep, the Porsche recommendation to drive immediately is based on emmision and MPG concerns, it has nothing to do with engine longevity.

Its indisputable that there is exponentially more wear on an engine at cold temperatures, and the more load you add at cold temperatures, the more wear.

See HOTRODSRJ’s COOLING TIPS Operating temperature vs power and longevity!

Now I don't recommend idling the car until it reaches operating temperature, although that would minimize engine wear, but idling the car for a minute or 2 or 3 is much better for the car than turning the key and driving off.

My warmup procedure varies depending on several variables, but when I rebuilt my engine, during the breakin period it idled a long time before it moved.

From cold, I try a time my move off until after thewhine form the secondary air pump (I think) dies and seeing the temp needle move off...a little...this maybe a minute or so

My rationale is more gradual even warming of the aluminum heads. We all have heard of the cracking issue yes?

here's my 2 cents:

Idling may be less stressful for the engine but will require more time to to reach normal running temp. Driving is harsher but the engine will warm up faster. I would suggest driving gently until the engine has warmed up.

Yes, but this is generally a result of air or a blockage in the cooling system. Shouldn't be an issue on a properly maintained car.

Which is exactly what Porsche suggests

I just start driving and keep it under 4500rpm for the first 10 minutes. It takes forever for the engine to warm up.