GeneralTso

I was recently told by our local Porsche expert to let the car warm up for 1-2 minutes before driving to avoid issues with pulled head studs. I couldn't find the thread, but I could have SWORN that Peter Z. and others suggested starting the car and driving it away (gently) just a few seconds later...

Where does everybody stand on this issue?

Thanks!

Jeff

Amber Gramps

Warming it up is always a good Idea. Even here in california I let it warm up a minute fresh out of the shed. You can feel it smooth out as it warms up so...do you have to? well, if it wasn't an engine issue it would be a tranny issue. the tranny is really stiff when cold and a blast when warm.

D.C.

My owners manual (86 Carrera) says start it and go. I dont follow that advise. I let it warm up for about 1 minute, because it runs better that way.

VNTGSPD

Drive it gently right away. There's lots of threads on this so you will see lots of opinions but most say to drive it.

I suppose if you are dealing with a newer fuel injected car, a short warm causes no harm but also you don't build much real heat if any in the engine and trans during a static warm up.

With a carbed car, sitting and waiting for the car to warm up just puts more crap on the plugs.

WitchDoctor

Pete Zimmerman's book recommends start and drive, BUT keep revs below 4000 until the temperature comes into the operating range.

DARISC

Pete's right (surprise, surprise!)

It is not a good idea to warm it up.

Also extremely important (and mentioned by Pete) is to drive with a VERY light foot on the gas pedal to keep the stresses down on the bearings when cold. No more than, say 1/8 throttle should be applied when cold. That's plenty to easily keep up with traffic while the temp. builds.

The highest percentage of engine wear occurs during cold starts.

Peter Zimmermann

Not only is "start & go" always recommended, by Porsche, for older cars, I discovered an interesting tid-bit that I mention on page 182 (997 discussion) of my 8th edition. "When the car is driven following a cold start a program prevents early upshifts (Tiptronic, of course), which allows the catalytic converters and the engine to reach operating temperature sooner." For the life and health of the engine, start & go - the internal bits can't reach operating temp and favorable clearances while idling!

Brett San Diego

Porsche didn't start this until the 997? Mercedes implemented this emissions reducing measure in the mid 90's (maybe other manufacturers, too, but I'm only familiar with Mercedes). Always causes lots of consternation for new owners of these used cars when their transmission doesn't shift out of first until 3-4000 rpm when cold.

Brett

DARISC

I find that interesting because what it is also effectively doing is operating the Tip trans to emulate proper manual shifting, i.e., when cold, shifting too early should be avoided to preclude the need to apply too much throttle (more than, say 1/8) and thus lugging the engine (stressing bearings), which is as harmful , if not more so, to the engine than reving it over 4k.

Pete?

dshepp806

I give her 30-45 seconds max, stationary, Then she's on the road.....I keep her no higher than 3K RPMs until I reach 148 degrees,..then she sees nothing above 3900 RPMs until I reach operating temp...then we (both) go to the "other" side...


........together...

Best,

DARISC

That's the ticket! Who/what sat on your car!

Mike Murphy

DARSIC, you must be an engineer, because only someone who has studied engine fluidynamics and thermodynamics would know the importance of this . Right on!

On a different note, BMW specifically mentions that you should drive immediately upon starting your engine (E46 models at least) in the owners manual. BMW has gone to great lengths to shorten to warm up process, and their E46 cars warm up faster than just about any car engine I've seen (electrically heated diesel CATs notwithstanding). Granted, the oil isn't hot, but the water temp in these cars goes from ambient to operating temperature in mere minutes.

Steve Weiner-Rennsport Systems

Totally concur with Pete,.....start it up, and drive it gently until warmed up. Remember, these dry sump engines get oil pressure very quickly so give it a 20 seconds idle and drive off keeping RPM's at or below 4000 until the oil temp reaches 180 degrees F.

Don't forget that the transmission, CV joints and wheel bearings all need to be at temperature before driving the car hard and that doesn't happen with prolonged idling.

Peter Zimmermann

"I find that interesting because what it is also effectively doing is operating the Tip trans to emulate proper manual shifting, i.e., when cold, shifting too early should be avoided to preclude the need to apply too much throttle (more than, say 1/8) and thus lugging the engine (stressing bearings), which is as harmful , if not more so, to the engine than reving it over 4k."

DARISC: Exactly!

Brett: Probably because a far greater percentage of Benz's are automatics. Porsche has always been concerned with warm-up emissions, which really plays into the start it & go philosophy. Thank you for letting us know this, good piece of info!

Daniel Dudley

Sorry honey, I had to leave without you. Steve and Pete SAID so.