Winter storage- to idle or not to idle?
 

Where I live the winter has been pretty rough lately: snow, salty roads and temps in the 20's. I haven't been able to drive my 89 Carrera for 3-4 weeks now.

Here's my question- do you guys think it's better to during these stretches to leave the car sit without running it, or is it better, or worse, to start it up and let it idle for 15-20 minutes to keep things moving. The battery isn't a concern because I keep a charger on it. How about flatspotting the tires? I've got Michelin pilots. Any thoughts or experiences? Thanks.

Just change the oil in the fall and leave it until you drive it regulary would be my advice. I pump up my tires to 40-45lbs to keep them from flatspotting.

A couple of the byproducts of combustion are acid and water. That why we put in fresh oil in the fall; so the engine doesn't sit with those things in it.
If you run the car until it nice and hot you tend to boil off the moisture. You'll find it condense on the inside of your oil cap. A relatively short warm up every now and then puts more moisture and acid into the oil without getting it hot enough to even drive off the moisture. Running the A/C once in a while during the winter is good for it but hardly worth what it does to the motor IMO.

-Chris
BTW: Has anyone noticed the cam pitting and rusting that aircraft guys have experienced using Mobil 1 during storage?

I would add...

Fill your tank to the top and add a fuel stabilizer to it. You don't want condensation forming on the inside of the tank.

I would not periodically start the car. You will never get it fully warmed-up and there is no reason to heat cycle everything needlessly.

I disagree. But I guess that's what the board is for...I don't let my car just idle, but I do run it during winter storage...once a month or more, long enough to get the oil to at least 180, hopefully driving out most moisture. I also pump up the tires before I park it, and yes, use STA-BIL. As the tank level drops, I fill from a can with fresh fuel, also STA-BIL treated. In the spring, another oil & filter change....it's worked for a few decades, the STA-BIL added to the procedure once it hit the market. But if it ever quits working? I'll stop doing things like this. ;)

Gee, I lay up the 911s whenever it rains!,but I couldn't conceive of putting the cars away for 5-6 months. I feel for you guys. I'd probably just leave it. Running the car would make me want to drive it when I couldn't and that's worse than just accepting it's not available.

I would say that starting your car and letting it idle is the worst thing that you can do for it.
We have pretty miserable winter up here, and you just accept that the Pcar can't be driven. Furthermore, just imagine what the salt will do to the bodywork.
On really cold days, when everything is frozen solid (snow, sluch, salt, etc) I take her out for a spin. Start up and let her run - open her up on the highway for about an hour and then put her away. It is great therapy!!
Starting er up and letting her idle is just going to clog everything up. She must run, built to be driven.....

It takes a lot of time for the 911 engine to warm up enough to evaporate the case codensation. You have ~ 3 gallons of oil that has to heat up. This means both thermostats have to open fully for all the oil to circulate. After that it takes many miles of spirited driving (ie - high head temperatures) to help the water evaporate.
Remember - water boils at 212F. The lower the temperature of the system the longer it takes for the water to leave. In the winter this is made much worse due to the cold air re-condensing the moisure as it tries to make its way out. Many 911s have a difficult time warming up at all.

SOOO - I would change the oil often if you run the car under those conditions.

EFI cars such as the Carrera are not as sensitive to sitting idle as are the older CIS equiped engines. Clean fuel and frequent use prevent a lot of headaches.

I wouldn't run the engine while in storage as has been said before. I would fill the tank with fuel stabilizer added, put it up on stands & put about 50 lb. in the tires. Also, I would rotate the engine every week or two to change the tension on the valve springs.

well, seems to be two camps here!

i don't lay mine up but if i did.....

leaving cars idle for long period does them no good at all - i wouldn't think that a couple of months wouldn't be a problem though.

i would run it maybe once a month, for a long period. like others have said it takes a long time to evaporate the moisture in there. maybe run it for an hour, i'd let it fast idle as well. hope you got understanding neighbours!:D

its a good idea to keep fresh fuel flowing through.

i'd rotate the wheels as well. leave the parking brake off.

My turn...
I live in Buffalo, NY...so I know a *little* about laying up cars for 5-6 months :( :(
- I run her as often as once every week or 2 weeks..but never at idle. Let her idle for a minute to stabilize things...then prop the gas pedal for 2200 rpm...and then let it run UNTIL it gets up to temp. Don't stop now...let it run *another* 15-30-45 minutes so that this won't be equivalent to a "short trip". Get the fluids up to temp and leave them there for a while. Once in a while, get in the cockpit and exercise the power windows and sunroof, and engage the trans ( if on jackstands) to move some oil around in the trans
Doing this requires you to refill the tank at some point ( laid up for 5 + months, remember??), so fresh fuel isn't a problem either.
Been doing this 10 years with good results...car is in an attached garage that never sees below 41 degF...so that should be factored-in to this response. Garage ends up at 70 degrees when you're done !
---Wil Ferch

I have the car in a frigid detached garage on an alley in an old town near Chicago. But I'm also of the "start it up" camp. I try to start it once a month to help the A/C seals (since my A/C still works well), and - to tell the truth - just to hear the sound and dream of spring. I last drove it a few days before Christmas - the salt has been pretty constant since then.

Agree with the STA-BIL, full tank, etc. above. Start it up to idle for a moment, and then raise it to 2,000-3,000 RPM to get the oil going. (If you still have Mobil 1 15W-50 in there, as I sometimes do, remember it is only good down to about 8 degrees F (-15 C). I keep the oil out in the same weather to see how liquid it is before I start up, and generally wait for a "nice" day (35 F???)

I bought an exhaust tube (like a neighborhood garage) to route the exhaust out of the garage (that way the heater doesn't pull in CO). Also, you can use the throttle cable adjustment for the cruise control to get the idle up - about 3-4 full turns should do it - so you can do other things while the car idles. Just remember to re-adjust before you shut the car off so you're not surprised some day!

I let it get up to operating temperature and then run it 15-30 minutes there. Total time depends on temperature, but usually 30-60 minutes. Luckily the few neighbors outdoors this time of year usually come by to shoot the breeze instead of complain. Stunning how clean a 911 looks next to the salty autos/floor of the garage!

Had the car on jack stands last year, and put it down to a discover a bushing squeak for half the summer. This year I'm just moving it back and forth to help the tires. I've heard flat spotting goes away with heat and driving in a few miles with modern tires, but would hate ($$$) to find out that's wrong!

4 Pilots - 4 Flatspots
 

Well, laziness has cost me inconvenience in the past. I put my car away for what was supposed to be 6 weeks. Circumstances changed that to 6 months!!!! Once the car was re insured, I went for a drive and found that all four tires had flat spots (Four, 3 month old Micheline Pilots) Luckily, they became un-noticeable after 1 month of driving. That'l teach me to let the car sit with 28psi for six months straight. I didn't have a chance to change the oil or put in any Sta-bil, but this was 3 years ago and there have been no problems since.

let me weigh in with the winter folks. car is put up for the winter (read, take ins. off and don't drive :( ). I put mine on jacks and use hockey pucks to apply some pressure on the struts/shocks. Start car up once a month, idle to 2500 rev when up to temp and let run for 20 min. = p/o'd neighbours! :D make sure you change the oil before the first drive. at minus 25 it makes no sense to do anything, so grab a beer and skip it to a warmer day!

Regarding getting the water out of the oil. I drive my car everyday in Seattle about 45 minutes each way to work, nice and wet. I have real bad water condensation in my oil. Makes that creamy white foamy paste up at the top of the oil spout. How long do I have to have the car hot to get all this crap out? I have even taken the tube from the oil tank to the induction box off and cleaned it out of there, It was full of it. I change the oil about every 3 to 4 thousand miles.