[sebapce]

Hello,

I have a problem with cold start for which I may have found solution. Right now my F30 335i (catless downpipe + resonator delete, today I'm going to bring back the resonator) is very very loud on cold start. For me this is not a big deal apart from the fact, that is sounds like a tractor or something. But I live in a peaceful neighbourhood so that just doesn't feel right.

Yesterday I noticed that i can kinda "cancel" the cold start by pressing the throttle a little bit and hold it like that. The car goes silent and I think even the rpm's go a little bit lower.

So my question is - is it safe for the car if I do this "trick" to interrupt the cold start?

Adding a little bit throttle feels very strange and uncomfortable when I do this right after the engine starts. But the press is really small, basically when the car recognizes that the throttle is indeed pressed i stop and hold it like that. And from what I can notice - this method puts significantly smaller amount of load onto the engine which even may be beneficial (since cold start is about cats anyway, and I don't have cat)

[White435]

You can interrupt the cold start by putting your car in gear.

[sebapce]

That's what I was doing in certain situations for example starting the car at 5AM. Anyway, simply putting the car in gear does not stop the cold start procedure. I have to drive, then after few meters the cold start is completely cancelled. My concern with this approach is negative influence for the transmission because you start with that extra kick coming from higher RPMs. I'm no expert, don't know what the results of doing this over and over would be. That's why I thought that maybe a better solution is using minimal amount of throttle to make it silent

[thejeremyman9]

Originally Posted by sebapce

That's what I was doing in certain situations for example starting the car at 5AM. Anyway, simply putting the car in gear does not stop the cold start procedure. I have to drive, then after few meters the cold start is completely cancelled. My concern with this approach is negative influence for the transmission because you start with that extra kick coming from higher RPMs. I'm no expert, don't know what the results of doing this over and over would be. That's why I thought that maybe a better solution is using minimal amount of throttle to make it silent

Agree, putting it in gear does not disable cold start, it just lowers the RPM a bit because you are under load, but the car is still under the cold start cycle. The loudness is because under cold start the wastegate is fully open in addition to raised RPM.

I assume you are not tuned; you can actually turn off cold start completely via tune

[sebapce]

Yes, I’m aware of the tune method, which can completely remove cold start. I’m not planning to tune the car just now. And surely I won’t tune it just to remove cold start. That’s why I’m asking about the throttle method. Whether this can be safely used or not. I know that this may sound a little bit stupid, but maybe tricking the engine to interrupt the cold start can cause problem, due to mentioned wastegate for example. I don’t know. As I already said, I’m no expert and don’t want to do this over and over if this trick can cause any problems.