I started-up my car today and...WTF!?!?!?

[tibra1]

Originally Posted by apecush

The cold start program you can hear is air injection to warm up the catalytic converters. Every single car on the road enriches the fuel mixture upon starting - you cannot hear this, nor do any of the tunes delete it. Fuel atomizes poorly at cold temperatures and as a result, a richer mix is needed to sustain combustion. If you ever tried to tune a car from the ground up, this would be painfully apparent.

Uhhh no..cold starts dont just heat up the cats..if you had read the article or the thread it would be painfully apparent....I know how fuel works in cold weather...what did you think I meant by "easier starts" in the cold..

[BPMSport]

According to factory documentation on this:

The diagnosis is used to check if the minimum secondary air flow is available to warm up the catalyst, thus detecting a damaged pump (SAP), blocked valves or disconnected tubes. It uses a secondary air flow meter (SAFM) to verify the amount of secondary airflow through the system and the oxygen sensors in order to allocate the malfunctioning engine side of the SAS.

Turning off the system stops all of the above from happening, because the ECU will not run those routines at all (if disabled properly). A common effective way of 'turning off' the cold start is setting the maximum RPM for the secondary air system diagnosis to be lower than idle, such as 100 or 200 RPM. The stock value is 4,500 RPM. This way the system never has a chance to activate, as the engine can not maintain such a low RPM without stalling,

There is absolutely no mention of "easier starting" or anything like that in this 200+ page comprehensive document. Anyone that has disabled the secondary cold start (as I have), knows that the car runs quite a bit better and starts exactly the same with the system disabled. With the system enabled, the ignition timing is offset to compensate for the extra air, and this causes the car to be slightly jerky when cold.

Personally I think the cold start sounds great, but it's primary function is for catalyst heating and there are no issues that arise from disabling it if the code is modified properly. Mine has been disabled for thousands of miles without a single issue. I'm not too concerned about the sound (although this is a concern for many people), it's more about how much better the car drives dead cold with the system disabled.

[DJDeez]

I was hoping Mike Benvo would have some insight, does not disappoint Now, if you have free refills on your popcorn, feel free to read an interesting document direct from the manufacturers of our catalytic converters here. There are several passages which state the exact opposite of Dr. Andreas Eder in regards to lower fuel consumption. They also state the purpose of cold start is to fulfill present/future emission legislation.

[swartzentruber]

Originally Posted by Mike Benvo

Personally I think the cold start sounds great, but it's primary function is for catalyst heating and there are no issues that arise from disabling it if the code is modified properly. Mine has been disabled for thousands of miles without a single issue.

Yes, and I'm sure your expertise in this area is greater than most of us, but keep in mind that you live in an area (SoCal) where you basically never have a cold start, so your experience may not be completely representative. If you live in a warm weather state, the cold start program likely doesn't serve much of a purpose. I'd think twice before disabling it in states where you can go weeks with temps in the single digits.

[tibra1]

^ Great point and exactly what I am stating..However you call it expertise..I call it fan-boyism..just because a guy has Vendor status doesn’t mean I am going to accept what he says as axiom.

A 200 pg document?..and only one little excerpt from it?..He would be more credible if the document referenced was posted here.

I know what I know about the true reason for cold starts and why they exist …its meant as a protection and for the engine to run hotter, faster, and more efficiently with less wear and emissions..and while people ofcourse are vehemently defending why they choose to disable it all I need to do is look at this statement and it says it all.

Originally Posted by Mike Benvo

it's more about how much better the car drives dead cold with the system disabled.

If you are driving a car “dead cold” like its up to temperature….then there are bigger issues at hand..I respectfully disagree with this and this will be my last post here..The other readers will draw their own conclusions, as I think I have present a plausible argument backed up by logic and data.

[Templar]

All of the arguing on the purpose of the cold start is really off topic, because the OP said his cold start is still active.

I'm wondering if it was something else in the tune that may have had a cause here, although it could be an isolated event.

[apecush]

Originally Posted by tibra1

Uhhh no..cold starts dont just heat up the cats..if you had read the article or the thread it would be painfully apparent....I know how fuel works in cold weather...what did you think I meant by "easier starts" in the cold..

"cold start program" referred to what people code off when they remove the catalytic converters. I thought that was obvious when I mentioned "cold start program you can hear".

[Raptor251]

Originally Posted by SehrSchnell

I hate it when tibra1 is right...

In all fairness its still emissions related!

[BPMSport]

Tibra, you are extremely rude. You love to draw conclusions based on your assumptions and make inferences which are simply not valid. I am on top of the Rockefeller center in new York, once I get back to my hotel you'll get a more in-depth reply that I'm sure youll argue with me based on links you find around the Internet.... Very conclusive information you got there from an article published years after MSS60 was produced....

Go do a search for my posts and I'm sure you'll find plenty where I discuss driving the car hard when cold is the worst thing you can do. I was referring to throttle tip in and normal driving characteristics when dead cold - like pulling out of a garage with 15 speed bumps like mine. Not sure what in your head told you that I was referring to driving the car hard when cold as mine doesn't ever remotely get close to the upper rpm range until oil temp is at-least 180 or 190. But of course you've based your argument on an assumption which was illogical. Doesn't surprise me coming from you. When you've actually spoken with engineers and tunes hundreds of cars then maybe you can chime in with something useful other than your baseless speculation.

[THE TECH]

Originally Posted by tibra1

The purpose of the cold start is to inject more fuel into the intake air stream when the engine is cold in order to enrichen the fuel/air mixture for easier starting...it eases wear on the engine

I have to disagree completely with this. Injecting more fuel into the engine would NEVER help ease the wear. You would need to introduce oil to the engine prior to start up if you were looking to ease cold start wear.

From my understanding, the cold start is purely for emissions compliance as the others have stated here.

[THE TECH]

Originally Posted by tibra1

Here you go some reading to go along with your popcorn

http://www.greencarcongress.com/2009...-new-ther.html

Quote:

"We want cars to warm up as quickly as possible, since higher temperatures mean less friction, less friction means less fuel consumption and, therefore, less CO2"

—Dr Andreas Eder, Head of Heat Management Pre-Development Projects, BMW

While you pulled one line of text from the article that helps your theory, the entire article is about lessening CO2 emissions. Having the engine warm faster may reduce wear, but that's NOT the real purpose behind the cold start program.

[M3garage]

Originally Posted by eNCore

Wow, is it that serious??? Did you have any other symptoms before the car stalled or it just stalled without warning? o.O

Yes, once before that the rpm went up and down a few times like stated above and the error on the idrive stated decreased power see bmw service. The second time is what i explained in the previous post. It was really embarrassing because i was showing the car to an old friend from the military i havent seen in years. And the stupid car shuts off on me and makes me feel like an ass.

[BPMSport]

Tibra,

Since you're such an expert - please explain why some cars in Europe have a much shorter cold start secondary air system operation, and why it won't come on after a cool down like it does in the US.

Based on your 'logic' it must be because the euro cars are built with stronger engines and can handle more wear than US ones? This is obviously absurd.

If you're going to make statements, you should have something conclusive to back them up. You complained to me about using a segment from an internal confidential factory BMW document (which was the only relevant section to cold starting) yet you base your argument on an Internet article that was not only focusing on a different subject but was written years after this dme was already in production.

Since you don't respect my knowledge and opinion, I suggest you ask Sal at evolve and he'll tell you the same thing. You've always had a bone to pick so please pick it with someone else.

[tibra1]

Originally Posted by Mike Benvo

Tibra, you are extremely rude.

I dont know what you are basing this on when in my post above I clearly said I "respectfully disagree"

But if it makes you feel better you win.. I lose..you're the expert... Im the novice..

[BPMSport]

Originally Posted by tibra1

I dont know what you are basing this on when in my post above I clearly said I "respectfully disagree"

But if it makes you feel better you win.. I lose..you're the expert... Im the novice..

Tibra, let's not try and backtrack here.

First you stated that there was "fan-boyism" instead of expertise being shared. I can only comment on what I know and have experienced from programming/coding/tuning hundreds of M3's. Whether or not I am a vendor is beside the point. It doesn't mean that I know more or less than anyone else. But when I do say something, I will back it up with factual data, documentation or my experience. Not an internet article from someone who is not an actual technician or engineer.

After that you decided to discount the fact that I used a portion of a 200+ page document - saying that I would be more credible if I posted it. First of all, I have nothing to prove to you. Second of all, I'm not keen on posting a complete internal document marked as confidential on every page. Thirdly, the only part of that document that was relevant to the discussion was the part that I posted. Posting the rest of it would not be conducive to this discussion.

Then after that you decided to misconstrue my statements about how the car ran 'dead cold', alluding that I drive my car hard before it's completely warmed up, which couldn't oppose reality more.

We have gotten into it in the past, and the reasons for your attitude toward me is still unknown. Let's just agree to disagree. You are acting like my response was unprovoked, but you knew exactly what you were doing in your post that merited my response.

[apecush]

Originally Posted by tibra1

If you are driving a car “dead cold” like its up to temperature….then there are bigger issues at hand..I respectfully disagree with this and this will be my last post here..The other readers will draw their own conclusions, as I think I have present a plausible argument backed up by logic and data.

Couldn't resist, could you.

Your habit of mis-reading or mis-interpreting posts and then attacking the post isn't helping anybody here.

[chuxdelux]

Originally Posted by SehrSchnell

[BMWM5NYC]

Originally Posted by SehrSchnell

That is quite funny

[E90///M3`]

Originally Posted by SehrSchnell

That... and he is wrong. Balance restored.

i was hoping BMRLVR would come in here and layeth the smacketh down on tibra1 but Benvo came through for us. win.

[TVMA Doc]

Originally Posted by eNCore

...RPM jumped up and down like crazy to around 3-4k (not sure) 3-5 times!!! The car was completely warm since the car was only parked for 10 minutes. It was the first time this happened. My car is 2011 with about 7.5k miles.

If it was Idle Control Valve problem, I thought it only happened on older models and in higher mileage cars?

Anyone experienced something similar?

Could this be due to the tune/software my car has? I don't want to name the company of the tune, but it is a very popular company.

I have a late 2011 E90 and it did this once. I just downshifted to first on the DCT and it stopped. I haven't had it happen again for the past two months.

I have just the standard BMW programming-no "tune". It seems to be normal, intermittent and not dangerous.