Warm the engine driving or in the driveway? - Page 2 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

tonycarreon · 08-09-2012, 09:09 AM

Quote:

Originally Posted by shadrach74

...

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

tony_fury · 08-09-2012, 09:13 AM

Quote:

Originally Posted by tonycarreon

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

stephen wilson · 08-09-2012, 09:39 AM

#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.

particlewave · 08-09-2012, 09:52 AM

Quote:

Originally Posted by BYprodriver

How in the hell anyone can think driving is less of a load than idling where you start it is beyond me.

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

stephen wilson · 08-09-2012, 10:26 AM

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.

shadrach74 · 08-09-2012, 01:21 PM

Quote:

Originally Posted by stephen wilson

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.

particlewave · 08-09-2012, 01:45 PM

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.

shadrach74 · 08-09-2012, 01:48 PM

Quote:

Originally Posted by particlewave

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.

BYprodriver · 08-09-2012, 01:51 PM

Quote:

Originally Posted by Mark_T

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.

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.

Topless · 08-09-2012, 02:00 PM

Quote:

Originally Posted by BYprodriver

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.

BYprodriver · 08-09-2012, 02:01 PM

Quote:

Originally Posted by particlewave

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

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

BYprodriver · 08-09-2012, 02:05 PM

Quote:

Originally Posted by Topless

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.

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

Topless · 08-09-2012, 02:11 PM

Quote:

Originally Posted by BYprodriver

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.

san rensho · 08-09-2012, 02:24 PM

Quote:

Originally Posted by BYprodriver

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, 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.

BYprodriver · 08-09-2012, 02:30 PM

Quote:

Originally Posted by Topless

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.

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.

jaykay · 08-10-2012, 04:58 AM

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?

tranceatlantic · 08-10-2012, 05:04 AM

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.