VarTheVar

Another reason is that the fuel mixture is extra rich during cold start and when the car is idling at cold temps. The combustion is also very inefficient until the metals expand and the pistons seal properly. During this time, the extra fuel fed into the cylinders combined with incomplete combustion leaves a residue of fuel in the cylinders. This washes off the protective layer of oil that's supposed to be coating the cylinder walls and can prematurely damage the bores as the pistons rings are scraping against the cylinder walls

2thHappy

Just drive off right away
m-engineering has ability to disable stop/start

VarTheVar

I like to keep it under 3k until I have at least 120° oil temp. Then maybe up to 4k the rest of the way up to 180°.
Also one thing to note for everyone is that our engines are turbocharged. Turbochargers spool based on load. So not only should keep the revs down, but also use less throttle within that rev range else your turbo will spool up. I try to keep it at 1-2psi of boost at most during the warmup. Although I'm not 100% sure about this, and if someone could shed some light that would be great, but I would imagine boosting at cold engine temps is just as bad as revving it out.

HappinessProcured

This isn't a permanent solution, at least on my car

VarTheVar

I believe regulation forces it to be on every time you start your car. Just set it in your individual settings along with auto blip and suspension and engine settings and switch to it every time you drive

aggie57

The fast idle on cold start is to heat up the catalytic converter, nothing to do with warming the engine oil. It’s an emissions thing. Your oil wont be at operating temp for 5 miles or more.

Capaldi

Gotcha. What causes the RPM's to go down?

I'm not sitting there, trying to get the car up to a reasonable temp, I'm wondering if I should wait the few minutes for the RPM's to settle down below 1,000 before I just go off and drive. Seems like you would want the RPM's to go down a bit before driving off on a cold start, no?

null

The point of the cold start is to warm the cats, a process that will be accelerated by driving. Just start the car and go. Some people would say just don't flog it till oil is up to temp, but no need to sit and wait at idle...

VarTheVar

The engine computer controls all of it. When it's in cold start mode the rpms are high, the timing is retarded, and the fuel mixture is rich. Even if you start driving the car right away the car stays in cold start mode until the catalytic converters get up to temp. If you have a louder than stock exhaust you can hear it come out of cold start mode as it quiets down a lot

aggie57

No, as others say you want to drive off straight away so the car warms up quickly. These engines run several different modes, cold start is just one of them. I’m not sure if the revs drop when it reaches a certain temp but that would make sense.

AlterZgo

The crunchy noise at low speeds is a common 911 issue. It happens to me in certain parking lots when temps are below 60 degrees. I don't know why it does it, but the first time it happened I thought something seriously broke... but it's just the combination of having big tires in a rear engine car and some odd interaction w/ the colder road surfaces that causes the rear tires to just freak out. It's totally normal and nothing to worry about. I though my car may do it less with 4 wheel steering but it still does it occasionally in lower temps and in parking lots at slow speeds.

null

Are you getting this when going straight at slow speed, or typically when turning at slow speed? Ackerman effect possibly, if the latter...

PetePorscheSD

RE: Stop/Start- I used that programmable button on the left of the steering wheel for the auto/stop function.... makes its simple.

Kornelia

I am also having a similar problem

Capaldi

Straight at slow speed