[swamy]

Without giving gas i.e!Makes the first gear jumpy. Such an odd issue.Has anyone else faced this?

[fshubert]

So to clarify, you start the car cold, in netural, foot off clutch and gas and the car revs above normal idle by itself? I've not experience anything like this myself.

[swamy]

Yes foot off the clutch. Happens about one or two times a week &the spike lasts only a few seconds before settling back down. First few times this happened, I didn't realize the rpm was shooting up on its own & thought something was wrong with the clutch - looked like a teenager learning to drive! so annoying

[Dcarter15]

What rpm is it jumping up to?

[BMWrules7]

Originally Posted by swamy

Without giving gas i.e!Makes the first gear jumpy. Such an odd issue.Has anyone else faced this?

Perfectly normal. Your engine management system is doing what it takes to get stability.

Neutral is fair game for the engine management system to increase rpm for various reasons.

[DrivenByE30]

From cold, you are supposed to let the car warm up about 30 sec before driving off...


From cold, Once you start, the engine over-rev above 1000 rpm (1250 rpm?) for about 10 seconds i think...

then it will drop back down to the regular 750rpm...

I personally never drive off right away when this happen... the car needs to wake up...

so if you drive off when it is reving at 1250rpm, of course your first gear will be jumpy...

[BEAR-AvHistory]

Originally Posted by fshubert

So to clarify, you start the car cold, in netural, foot off clutch and gas and the car revs above normal idle by itself? I've not experience anything like this myself.

You might not have noticed it but, dead cold start fast idle is very normal in cars. Modern fuel injected cars come out of it fairly quickly compared to old carbureted ones

[fshubert]

Originally Posted by BEAR-AvHistory

You might not have noticed it but, dead cold start fast idle is very normal in cars. Modern fuel injected cars come out of it fairly quickly compared to old carbureted ones

You're right! Funny but I just glossed over it but now recall the days of the Holly double-pumper on my Chevelle taking a while to get to normal idle.

[rking117]

Originally Posted by DrivenByE30

From cold, you are supposed to let the car warm up about 30 sec before driving off...

I have heard many conflicting stories about this. As for the ///M versions because of how they are built you definitely need to let them idle warm before driving off and then keep them under 400 RPM until the engine warms up completely.

But as for any other non ///M i have heard you shouldn't warm them up and that they are made to drive right away after cranking them. since this information came from BMW reps i think it is pretty sound info.

[rking117]

Originally Posted by fshubert

Holly double-pumper on my Chevelle

Hmmm, totally different technology but ok i am with you.

[Thumper333]

Originally Posted by DrivenByE30

From cold, Once you start, the engine over-rev above 1000 rpm (1250 rpm?) for about 10 seconds i think...

then it will drop back down to the regular 750rpm...

Correct, this is for emissions, SAI, heat up the cat, ect.

Originally Posted by rking117

But as for any other non ///M i have heard you shouldn't warm them up and that they are made to drive right away after cranking them. since this information came from BMW reps i think it is pretty sound info.

It's complete BS. LOL Unless by BMW rep you meant "Engineer" and not salesperson (and even then I would have some follow up questions and request some documentation).

No car is "designed" to crank the engine and then hit the gas before the starter gear finished spinning. Unless it has an electric oil circulation system that starts when the doors are unlocked. Even then any such blanket statement is a sure sign of being wrong. For example, is the start up procedure the same for;

A car that was just driven normally until normal operating temp was achieved, then turned off for 20 minutes while shopping.

And a car that has been sitting at the airport for 30 days while on a trip?

Seems pretty obvious that the conditions and situations are completely different and unless the car can somehow retain oil pressure for 30 days giving it a load and driving RPMs immediately would be foolish. The thin oil film retained after extended inactivity is there to protect the car from dry startups, not driving loads. If all that was needed for normal operation was that film then we wouldn't have 5+ quart oil pans. We would have 1 quart pans (or no pans, since theoretically the oil in the filter would be sufficient) because once the first time the oil circulated and coated the parts we would have full protection forever under this theory.

30 seconds would be what I would call the minimum, and anything over 2 minutes is silly. Remember, if you're using a muti-weight (which we are), the oil flows quickly when cold which is good to get it to all the areas of the engine, but that also means it is THIN which means limited protection. This is why full throttle, RPMs, etc are not recommended until the engine is at full operating temp (when oil is thickest providing maximum protection). This is also why even though the oil flows quickly even at 0 degrees it does not thicken until it is warm/hot, and in 0 degree temps the car will take longer to warm the oil. If it's below 0C, allowing a slightly longer idle is not out of the question, but still nothing over 5 minutes.

A short idle process gets oil to vital parts so that conservative driving can be achieved which will then warm the engine to full temp quicker than sitting at idle.

But crank and go? well, if it's on the internet it must be true....

[Billfitz]

Originally Posted by fshubert

I just glossed over it but now recall the days of the Holly double-pumper on my Chevelle taking a while to get to normal idle.

That's because they used a heat sensitive mechanical linkage that kept the throttle open until the engine warmed sufficiently that the idle speed could be reduced without stalling. Often it was tied in with the mechanical choke as well. It was usually mounted on the exhaust manifold, a simple spring that lost tension when it heated, and the exhaust manifold is the part of the engine that gets hot first. Modern computer controlled fuel injected engines tend to be more precise, but things can go wrong with anything.

[ft1330]

Originally Posted by swamy

Without giving gas i.e!Makes the first gear jumpy. Such an odd issue.Has anyone else faced this?

Yes I have this and I was made to believe it was normal from reading various reports on this forum. This is separate from the initial rev up on start. The issue described by the OP is after you start driving off, it gets jumpy. That's way after the initial start up rev. I notice this during the cold season especially.