Warming up Car... How long?

Just bought a 1999 996 C2 and the owner told me that I should wait until the car reaches the second line on the temp guage before driving off. (It rests on first when cold) How long do you all wait before taking off... This morning I was sitting there thinking, its been 6 minutes, and I am still waiting..... What do you guys think.

ABSOLTELY NOT!!!!! You should NEVER let these cars warm up idle in the garage, etc. And never REV the engine while in idle trying to wiat for it to warm in an attempt to warm it up more quickly. Easiest way to damage your engine. The manual clearly states to start the car and drive away immediately and keep the revs low till at operating temperature. This process brings the engine to temp quicker and safer.

I never let the engine go above 2500rpm until temp reaches 180deg!! Yea I know a Boxster, but they have simular engines and they can get jiggy too!

start and floor it!!! out of the garage thru the neigborhood...hitting a couple of school kids and old ladies.....see the smoke in your rearview mirrors.....pull over and pull out all your hair!! Never (like Dell wrote) NEVER let the car idle....start and drive off....like the manual says don't go over 4000 rpm untill the needle hit 180....I think never go over 2500 (like rbennet wrote) before the needle is past 180......you will enjoy your P a lot longer.

What they ^^ said! Keep it under 4,000 RPM until car gets to normal operating temp, which in my car is when the needle is between the "8" and the "0" at the 180� mark.

First I always warm the car until the the car comes to idle - about 700RPM, which takes about 2 or 3 min. tops. Then I keep the RPM's under 4K until the car comes up to temp, about 180 degrees. You can actually feel the tranny warm up and shifting is much easier. After that I consider the car ready to go.

The reason they want you to drive the car right away is not clear...some say it is because they want the transmission to warm up as the engine warms up...some say it is an anti-pollution thing (those German environmentalists)...can't see what is actually wrong with idleing to warm some before you drive (anyone explain the science here). I think riad has it right.

The short answer is that the engine will warm up faster that way and thus be "protected" sooner than later" as long as you keep the RPM's down during this warm up period. It's all about engine life.

Its okk, I dot warm up my BMW, but I do on my 996... I really dont know which is correct & what to do... argggh

I give it 30 seconds or so b/c it's choppy otherwise when driving off

Wow, this is something I've always wondered about, being somewhat automotively challenged (most of my automotive knowledge comes from listening to Car Talk, but try not to hold that against me). I understand the part about it being OK to drive off almost immediately in above freezing temperatures and would allow a quicker warmup (with a few minutes warmup at idle in sub zero temps). http://www.cartalk.com/content/colum...anuary/01.html But I always thought it was not a big deal to let the car idle for longer, say 10-30 minutes in the morning (save for a little extra pollution and miniscule wear and tear). Is there something unique to P-cars wherein an extended idle is not recommended? http://www.cartalk.com/content/colum.../April/01.html If idling is indeed bad for the car, I guess corollary question would be at what time interval would the marginal benefit outweigh the cost of having to restart the engine while say, running back into the house, versus just leaving the engine idling. In the pasts I've left the car running in the driveway if I think I will be 10 minutes or less.

The car is designed to idle higher when it's cold for a reason, whether it's 80 or 8 degrees out I always let the car come to idle (about 700) before moving. Starting your car and driving it normally while the engine is cold just does not seem like a good idea.

Get in, start the car, put on your seat belt and you are ready to go. Agree that you should not exceed about 4000 rpm until engine is fully warmed up.

what a load of crap. what is he, 80? the newer cars, by that i mean since the 80's don't need that. just don't get too crazy for the first 2 miles or so the engine warms up a lot faster by driving and tires can come to the operating temp.

http://www.cartalk.com/content/colum.../April/01.html If idling is indeed bad for the car, I guess corollary question would be at what time interval would the marginal benefit outweigh the cost of having to restart the engine while say, running back into the house, versus just leaving the engine idling. In the pasts I've left the car running in the driveway if I think I will be 10 minutes or less.[/QUOTE] so yoou are those people pamper their p-cars and complain all the troubles your baby gives you like faulty plug, rough idling, bluh, bluh, bluh. Morden "high performance" engines are design to operat at high temperature to acheive efficiency and HP with the advan of ECU and metallegy. there is only one way to baby these cars is to drive ithem like you stole them the way the germans intended them for.

This is exactly what I do - seems to work great.

By the way. It doesn't matter how you warm the car up, just as long as you fully warm it up before driving it hard. You do no damage letting it idle til warmup or driving it immediatly. So do whatever tickles your fancy. If the questions is "is it necessary to warm it up fully before driving", the answer would be no.

Is there any recommendation before turning the ignition off after returning from a drive? I heard you should let it sit and idle for avery short period, any truth to that?

I guess there is mix emotions, but It sucks when its 5:30am and I am sitting out in car trying to get to the gym thinking " I have been here for 5 minutes now, and still waiting" I guess it really doesnt matter as long as I keep the revs down. Thanks for all the responses, also is normal temperature in between the 8-0 or around that area? Do these cars ever overheat in traffic? I just don't know what to expect, and the last thing I want to do is harm my car from lack of knowledge? What is everyones experience? How high has temp gotten on some of you? I have had everything from 67 camaros, to new 3 series and everything is different.

In my Audi, if the engine is too hot, the radiator fan will continue to run after the key is out of the ignition. Do our cars do that too (haven't driven my car in 100* temps yet)?

996's will do the same thing.

I'm with riad! That's exactly what my routine is when warming up my car. Idle down to 700 rpm or so, then I'm off.

Me too, wait for 700RPM, it takes approx 3 -4 mins, but the temp gauge still indicates that the engine is cold.

You guys are simply wasting time if you're sitting in your car for 3-4 minutes. Start the car...give it a few seconds to get the oil flowing (like noted before, usually the amount of time it takes to get your seat belt on and get yourself adjusted), then drive off. If it's cold out, just don't hammer on the car. Modern motors w/synthetic oils will not be harmed by driving off immediately. An idling only car warms up the motor, but nothing else. Driving the car warms up all the components at the same rate, helping to extend the life of major seals (know of any on 996s and Boxsters?) and "in between" components. Not to mention there are some components that simply can't be warmed up w/o driving the car. I'm fairly certain it's not good for a car to be driving with a warm motor and a cold transmission and/or brakes. ..nor is it safe!

Doug, Let me ask you this question then; why do they engineer the car to idle faster when it's cold? Rob

Dunno...? I will say that with almost every car I've owned, a quick blip of the throttle will bring it down to a reasonable idle...if not the 700 rpm you mentioned. Still...???

I've posted this question on Renntech... if those guys don't know, no one does.

OK, I'd say it probably takes you one minute to turn on the ignition, put down whatever you're carrying, get belted in and well situated before driving off. So it takes me another 2 minutes, I'd hardly call that a "waste" of time. How is driving with a warm motor and a cold transmission and brakes any worse or more unsafe than with a cold motor? Aren't you still warming up the other cold components by driving? Regardless of the warm-up time, none of us hammers the motor until proper operating temp. Is there some mechanical detriment to the components if they're not all warmed up at the same rate and time? From what I understand, the case against idling (for any car) has always been about fuel economy and pollution, not mechanical damage. Are Porsches the exceptions?

The reason you do not sit around and warm up your car in Germany is because if you let you engine idle for more than 2 minutes you can get a ticket. Personally I let my car idle for 30 - 60 sec and then keep the rpms below 3000 till she is fully warmed up. Am I correct, probaly not but now you know the German law and my procedure.

I believe excessive idling at start up leads to some consequence of not having complete combustion of the fuel. This can cause "damage" somehow, but i am by no means the expert. (moisture as well) Just trying to remember why i was told not to do it. My biturbo Audi S4 manual stated that you needed to see the OIL temp move before harder driving. There were times when the engine temp went up pretty quickly but the oil took considerably longer. Why don't we have oil temp gauges?

I think we all agree not to let you car idle until the temp rises. My engine runs rough when it's cold, almost like it has bad gas (but not that bad) and my 2001 did the samething. As soon as the idle hits 700rpm it purrs like a kitten. I really don't need to be anywhere 2 minutes faster, so why not?

Well now I'm very curious, too. I was told what I was told and it made sense to me when I was told...and I'm sure I was told by an "expert". I'd love for an engineer to chime in here and set us all straight...

I tried to keep the car under 3000 RPM right after I start the engine and it didn't work out very well, I didn't let the car warm up first, I just drove off, the car stalled pretty bad on 1st 2nd and 3rd gear, feels like engine is shutting off, from another article I read few days, if your car stalls then it means you need to let it warm up a little bit.

The mixture needs to be a little rich at cold temperatures to provide enough fuel for combustion. At cold temperatures, some fuel condenses in the intake tract. This effect is similar to the use of a choke on a carbureted engine. Running a bit rich at elevated speeds also helps to heat the catalyst up faster to reduce start-up emissions. Unless its below 0 deg, I can't see the value in sitting for 3-4 minutes to allow the engine to drop from cold high idle. Cheers,

Interesting discussion. I'm no engineer, but here's my reasoning: Fuel has a flashpoint. On cold days, you have cold fuel... assuming that the composition of the fuel hasn't changed, the specific flashpoint should be no different, however, the amount of energy required to reach that flashpoint is increased. Running a little rich on cold startup should increase your chances of achieving combustion and thus achieve startup. Now that I'm thinking about this, does cold weather significantly increase the fuel flashpoint due to moisture condensing within the fuel? Engine emissions are reportedly worse on startup and at idle. Running a higher startup idle is not only the result the richer condition, but it also helps to get the cats warmed up to help further reduce emissions. I think that the manual recommends driving right away in an attempt to reduce overall emissions, especially idling emissions, and to reduce the chances of emissions toxicity (e.g., letting your car idle in an open door garage).

I think everyone's on the right page here. Definitely the choke on my snow blower serves the same purpose, but I always wait for that engine to warm up before I start throwing snow! Keep in mine Porsche may just reccomend something for liability reasons. This morning I started my car and it took less than 2 minutes for the car to idle normally, so I'm sticking to that game plan.

Hey, at least we are talking about starting the car to take it OUT of the garage. Can you imagine what this thread in the F-Car forum would sound like

1) Pull off car cover 2) Dust lightly with endangered snow owl feathers 3) Stare admirably for several minutes, turn around then back again quickly to notice any dust the owl feathers missed 4) Have a friend help push the car out of the garage as not to annoy family members with that 8 or 12 cylinder roar 5) Gently open door with kid glove on 6) The car is 4" off the ground, slowly get in to avoid back injury, close door 7) Put on racing gloves 8) Hold steering wheel and gaze out the windshield in admiration 9) Place key in ignition (it's on the right side) 10) Step on clutch, disengage transmission 11) Slowly turn the key 12) Listen closely for wearing timing belt 13) Get out and open engine lid 14) Examine timing belt 15) Write down date/time/mileage to ensure accurate timing belt change 16) Have a friend follow you in his BMW 17) Drive to dealer for maintenance 18) While driving home in your friends bimmer , tell him how stupid his iDrive is.

Thanks Rob! I needed a good laugh before my coffee kicked in ...in a nother related note, the wife and I were watching the ALMS 12hrs of Sebring this past weekend as we are watching the starting grid head out and get introduced (type of cars) the wife says as they go through the GT class, "is that a Ferrari F430 in the field?" I pause, look at here, she has a puzzled look, then I ask her, sure why not? and her response is "I thought those cars were garage queens". I almost shat myself from laughing so hard! I should note that my wife is a track junkie herself and really knows her cars (damn I'm lucky) and when she asks the other Docs she works with at the hospital that have F-Cars, she says, "hey, you should come out to the track this weekend, our local PCA chapter is having a DE event". To which they reply, "are you kidding?....these cars are not meant for the kind of 'abuse'...." YOU HAVE TO BE KIDDING ME!!!

C'mon! Didn't you ? "START SNOWBLOWER AND IMMEDIATELY START BLOWING SNOW." I wonder how long it takes the cats to warm up on this Bad Boy...

LOL That's a good one...

Interesting. The more I think about this, the more I suspect the reason the manual states to drive off immediately instead of letting your car idle in the garage is for environmental reasons. First thing in the morning the catalytic converters are stone cold so they don't work that efficiently (that and choke = lovely smell of unburnt fuel on startup). So the quicker you drive off, the faster the main cats light up and the less pollution the car emits. Do our cars have pre-cats in addition to main cats?

riad you're hilarious...thanks. This is one of the thoughts as I stated earlier....the environmentalists are quite strong in German manufacturing.

Riad, I believe the idle is higher at cold start to warm up the cats. My old RX7 has an accelerated warm up mode which revs the car to 3k upon cold starts for 10 sec or so. A blip of gas takes care of that. Cars definitely run rich at start. That's why short trips are inefficient. Engines run best at operating temp. So, as soon as oil starts to flow, I take off slowly under 3k. You may have a foul plugs? How often do you drive your car? If it's not daily, try doing that for 3 consecutive days to see if any change in idle when cold.

I drive my car daily all-year-round. The engine just sounds a bit rough when it starts, nothing out of the ordinary and my 2001 did the same thing. I don't think its harmful to let the car come to idle, or not, it's whatever everyone's more comfortable doing. We ALL agree that we keep the RPM's down until the car come up to temp, about 180 degrees. So we have that going for us, which is nice. Rob

As usual Rob I agree with you, but I take one exception.... A BMW beemer is the motorcycle, the car is a bimmer...

Ok, it's time to get back to the orginator of this thread. Hey dant? Are you confused yet?

I think we lost him. He went out, sold his Porsche and here he is warming up his new wheels . . .

I knew there was a difference but had no idea which was which.

Here's my Honda, next to my 2001 C4.

cars run rich when they are first started. the rich running condition at idle when cold can "wash down" the oil from the cylinder walls at a higher than healthy rate. it can also lead to fuel dilution of the oil, the oil then has a lowered flashpoint and loses film strength...extended idling is not as detrimental as it used to be now that cars are very precisley metered with EFI, but dilution and wash down still occurs. The best strategy is to start the car,drive away, and kep the revs under 4000 until te coolant and/or coolant/oil rise to operating temperature. Also, there have been instances where catalytic converters have overheated from extended idling.

Did you see my snowblower? Seriously, thanks for the info.

no problem! get a plow for that 911! more fun than a snowblower, but the snowblower is cool anyways!!

Great looking snowblower...has it ever been used or did you just finish Rejexing or Zainoing it or whatever? Honda...like no other.

Whats a "snowblower" ???

It's what you get when you breed an Eskimo with a *****.

Thank you Mr. Carl Spackler.

I came from the beemer forum and if you asked a question like this, you get about 8 responses from the smart *** 16 year olds that just had their daddies buy them an M3 saying "repost" or "why did you buy a car like this if you can't even operate it"..... At least you guys add value

There are a few of them here, easy to spot by the way!

Oh Rob.....I do NOT envy you guys up in the NE! You crazy snowblower kinda guy

It's getting old for me too Dell.

Caddyshack references never get old.

Twenty bucks says the Smails kid drives right off without any idling. You guys crack me up. Seriously though, the inital higher idle (enriched air/fuel mixture and increased airflow) is necessary simply to acheive a smoothly running cold motor. Try starting with a clean slate and progam the startup and idle yourself which is something I did on a 944 turbo motor. It was pretty apparent the motor won't work well without a little "goose" to get things headed in the right direction. P.S. I use the exact same procedure as Riad.

The higher idle is computer controlled and not a result of increased air/fuel feed. This is not to say that the car does not run richer at cold startup, but it is not what controls the idle. I do not run air injection on my 996 and it does not effect idle one bit. Perfectly normal and needed for smooth idle.

who's the guy in Caddyshack the walks out and trows up in the Porsche?? that's waht happened to me when i got the parts bill for my first engine rebuild!!!

Yeah, that was just wrong!

Indeed. I was wondering if anyone else noticed it. Get your trivia here! That was Spalding, grandson of the Judge Smails. "A flute with no holes is not a flute; and a donut with no hole is a danish."

I get in the car and go as I am in an innner city garage the fuel stink gets really bad if I leave if for 1 minute. The car is if fine but transmission a little stiff in the cold, so I keep under 4000 rpm until need operating temp. TBH more worried about the transmission than the engine. Once the engine if firing away it is warming up anyway so just go!

I have to say you lost me there. Yes, the higher idle is computer controlled. I would have to say that is obvious. What does the computer control? The fuel mixture, ignition timing and the idle air bypass valve (I think you called it "air injection"). How can the engine rpm change (without changing the load on it) without changing the fuel mixture or the airflow?

I mentioned this discussion to my wife - and the fact that's it's gone to five pages now. She wants to know if you all warm your wife up as long as you warm your car up.

Kudos to your wife!

You mean we are supposed to warm them up as well? I thought it was all about us!

Yes. And for the record, Julie's feet can get colder than any metallic car part left out overnight in freezing cold temps...so she puts them on me!

Yeah, what is it with the "cold feet" thing?

On two occaisons where I left the 996 idling to warm up some, as soon as I put the car in reverse the CEL lit up......after about two days it turned off. hmmmm....

I've scoured the net for more information on this topic. Does anyone have a link to an engineer-based site that concretely answers this issue one way or the other? For the record, I used the Riad technique. Start car, wait for fast idle to end, drive off at low RPMs until car at optimal operating temperature....then drive HARD.

Lo and behold, I found something just after my post from the Army Corps of Engineers: http://www.nad.usace.army.mil/cold_w...iving_tips.htm "Starting: Let your car warm up from one to two minutes before driving during winter temperatures so the oil circulates to all moving parts." And from the BBC : "...oil not only settles in an engine, but the cold also makes it coagulate; it takes a minute for the oil to thin out and get pumping everywhere it needs to be, and running high RPMs with cold oil creates an unpleasant metal-on-metal environment which is really quite detrimental to an engine's health. Give it just enough to keep running; wait at least a minute or two before even putting the car in gear for the best results. Once the engine is warm, it can be run just like any other time; except when it's that cold, it's probably also fairly snowy or icy."

You are looking for a definitive answer where none exists (just like in real engineering). I suppose we could practice some scientific method...develop a theory (hypothesis) and go get some data, but that would take all of the fun out of arguing. Mostly people like to techno-babble without any real data (an appropriate, representative data set) then violently argue their point. Even in the above post...there is no data to support the recommendations. Oh it comes from the Army Corp. of Engineers so it must be good...BS. The most technical P-car site I have come across is Renntech.org.

Ask any racing team and they will tell you there is no point sending a car out on the track with cold oil, as the resistance of the cold oil will be visible as power loss in the engine - not to mention the increased wear on the engine !! Abuse any engine with cold oil and the parts will experience excessive wear because the oil is just not flowing quickly enough. The only question is how long do you need to idle to get the oil just warm enough to drive away. I go for the 2 mins approach: Start her up, drive her gently 10 meters out of the Garage, leave her idle while you close the garage, and then drive away without abuse until you both reach working temperature. (instructions for warming the car - not the wife)

Irish - you need to get an automatic garage door opener. I'm glad you clarified that, because you NEVER want to leave your wife on "idle" while you close the garage!

I don't think this is a question for the "race team", I know their cars are quite warm when the race starts, that's not the question. What is cold oil? How cold? What is the right temperature for oil, lubricants, other parts to be at when you start to drive? SHOW ME THE DATA!!! Not more opinions...even if they are a race team (many of which are not successful). YOU still do not provide any data (my original point).

Didn't someone mention synthetics earlier? I don't think the ten quarts of Mobil 1 I put in my car a few weeks ago are going to have the clumping effect as previously mentioned. For me personally, I just wait for the compressor to kick off on cold starting. It drives less with those jolts that you get if you aren't linear with the accelerator when driving it immediately after starting it.

After doing a fair amount of reading on the web, I remain convinced that the start the car when cold and drive off procedure is simply a part of the save gas and reduce emissions campaign. However, it would seem that letting the car warm up gingerly until the cold start rpm advancer has ended (usually about 1-2 minutes) is the ideal method. Put another way, why wouldn't you want to warm up the car this way? It lets the oil warm and circulate to all the parts of the engine before any potential harmful wear during cold usage. Here's a pretty interesting and somewhat scientifically-oriented article from Canada.

On the subject of engine warming up. I hear a high pitch sound/whine like a small high-speed pump. Not really noticeable because it�s on when the car is started but defiantly can hear it shut off after the car has run for about one minute. Any idea what that is? (car is a 99 Boxster, have only had it a couple weeks now and my first p-car)

That would be the muffler bearings spinning around until they warm up.....

Really? Bummer, I thought the PO mentioned he had replaced that already. Oh well, my Blinker fluid is low so I�ll order some of that at the same time.

Be careful not to use just any blinker fluid. If you don't use the Porsche recommended fluid you could wear out your bicoupled flanger prematurely... ask me how I know

That noise is the motor of the electric blower that injects air into the engine during the first 1 minute from a cold start. Helps warmup the exhaust. Normal.

ah, thank you.

Wow.. 6 pages so far. I can't swim though all that to see if this is stated, but it's my understanding that the issue with allowing a car to warm up as it idles is historically because a car just clicking over has less chance of circulating oil around the entire block. While I believe that would be true of my 76 spitfire and 82 jeep, I'm not sure that it would be true of a P car. Keith