Warmstartproblem der anderen Art (GELÖST) | Posts 16+

If the simulated cold start works, shouldn't adapting the starting fuel quantity also work? A cold start should imply a higher EGR (Exhaust Gas Recirculation) rate and earlier ignition timing. Or does the Engine Control Unit (ECU) then also accept the lower engine speed?
hg
Herbert.

Hello,

Hutfahrer wrote:

Let's try something from the troubleshooting corner: Does the temperature sensor, which is switched to a fixed value for the initialization process, trigger more than just an error memory entry? Does the MIL (Malfunction Indicator Lamp) turn on, and could it potentially also switch into limp mode?

not at AFN.

Quote:

Falls nicht, wuerde ich gerade bei einem aelteren Fahrzeug auf den Fehlerspeichereintrag schei**en und waehrend der Bestromung des Anlassers den Temperatursensor auf einem der Software gefaelligen Festwert umschalten.

Sure.

Quote:

Experimentally, it might even be possible to find a substitute value that doesn't trigger an error memory entry. Setting up and creating such a workaround seems justifiable in terms of effort. In the case of an older used vehicle where the manufacturer rejects any support and blames the driver for errors, I would be quite unscrupulous in devising and implementing a solution to fix the problem.

in der Pölerszene fahren viele Leute die TDIs mit einem Stereopoti, mit dem sie simultan die Werte für KW- und Kraftstofftemp. runterdrehen (Seite von Alex, der imho diese Idee als erster hatte: http://kfz-meister-betriebswirt.de/IbizaUmbau/Zusammenfassung.htm, ohne Gewähr für die Richtigkeit aller dort gemachten Aussagen ). Damit kann man in der Übergangszeit ein Vor- und Nachglühen provozieren und den Spritzbeginn nach früh verlegen. Die Simultaneous positioning prevents the MSG (Message Security Gateway) from detecting any tampering and logging an error.
This should also allow for a simple and "non-intrusive" solution to the described problem.

Best regards, Uli.

Hello everyone!

Um jetzt vom 100ste in's 1000ste zu kommen...

@Spati: The manufacturer does NOT describe in its user manual something like "...release the ignition key just before, if you think the engine might start..." or "...release the ignition key after exactly 0.8375 seconds!" or anything similar .
We technicians always try to protect the starter motor and enable its reuse, before it is accelerated by the engine, of course. 0.5 seconds are hardly controllable by humans and therefore represent the tipping point between good and bad or better. But starting for too short a time remains a "misuse," whether you like it or not .
By the way, my "older used" car already had this issue when it was brand new - maybe twice a year. Since I never managed to trigger it, there were no official complaints under warranty, and besides, I wasn't knowledgeable enough about diesel engines back then to understand what was happening or why.

For the sake of completeness, I would like to reiterate the following:
The phenomenon described by the TE (Oldi ) has NOTHING to do with the classic "cold start problem," because in the latter case, it would regularly take well over 5 seconds to start, or even significantly more! Furthermore, it NEVER results in the 500 RPM running speed.

@Uli: The original poster is not bragging .

"@Ulf & Co.: I don't know how far your gaming or crafting instincts (or perhaps compulsions? *fg*) go, but is it really worth waiting 1 second longer on every COLD start just for the intellectual amusement? The effort involved in planning and "rebuilding," maybe around 12 hours, equates to 43,200 seconds. That means 43,200 extra cold starts would be needed before the time saved actually balances out! If you were to extrapolate this thought process, it would take approximately 30 years if someone started their car an average of 4 times a day, every day of the year."...and is it worth it?? Stay a little bit grounded, okay?

As Uncle Autoschrauber says, this phenomenon is actually not even worth mentioning if you know how to interpret it and live with it .

Best regards from Munich!

If my car always has an "epileptic fit" every time I try to start it for too short a period, that's not a malfunction , but rather a quirk of the technology.
In many product areas, friendly customer service representatives try to convince us consumers that we are the problem when there are shortcomings, even though the manufacturer clearly did not incorporate normal human behavior into their design requirements.
And if something like that is annoying, you start thinking about whether and how to get rid of it.
hg
Herbert.

Servus HerBärt!

Your thought process is correct to a certain extent, but that's not quite how it is.
... Ich geh jetzt echt mal meine BDA vom Audi holen und nachschaun... [Years later]
Photo below. *Pea push-ups* (or something similar, depending on the intended meaning).

Quote:

...Setzen nur unregelmäßige Zündungen ein, den Anlasser noch einige Sekunden weiter betätigen (maximal eine halbe Minute), bis der Motor aus eigener Kraft durchläuft. ...

Now we are all smarter .

Again: This so-called "problem" is NOT a problem if sufficient preparation time is provided. Therefore, it's clearly user error.
Objectively speaking , whether you call them customer advisors or customer appeasers, it doesn't matter.
...zumindest in DIESEM Falle hier...

Best regards from Munich!

PS: Before the peas turn into rocks and fall on me: Of course, I don't know what Audi says when someone manages to drive around a corner three times with the starter engaged for up to half a minute, get cigarettes and bread three times, and then complains about the broken starter .

DO NOT EDIT! @HerBärt

Ganz übersehen, was LINKS unter den allg. Please note:

Quote:

Sobald der Motor anspringt, Schlüssel sofort loslassen - der Anlasser darf nicht mitlaufen.

..and here I claim with 100% certainty that NO ONE hears or feels the engine "starting" beforehand in this phenomenon, but rather, due to routine, they simply (based on feeling) release the key after a fixed time X, because they already know, based on experience, that the engine will start NOW. This included me regularly!
And THAT is exactly the problem, or rather, the "misuse," in this thread.

Rätsel gelöst.

Best regards from Munich!

EDIT: Right/Left... Yes, we've been there before *g*.

Quote:

And EXACTLY THAT is the problem in this thread, or rather, it's a case of "misuse." Puzzle solved. icon_wink.gif

Ditto. How to start a car is something one should actually learn at driving school and doesn't belong here.
Even if the engine is running at a few hundred revolutions per minute due to improper operation and software-related issues, like a Lanz tractor.

Perhaps this has also led to the increasingly common start buttons or key fobs/chip cards that need to be pressed to start the vehicle? Simply because customers are too stupid to start a diesel engine with a traditional ignition switch?!

Hello,

DieselBär30x wrote:

@Uli: But the original poster isn't being rude.

That wasn't the question, but rather whether, in addition to an error message, a limp mode or other emergency procedures are triggered when the coolant temperature is manipulated. In this context, I showed a possibility of how to even prevent the error from being logged: The engine control unit (ECU) accepts the reading if the fuel temperature doesn't deviate significantly from the coolant temperature (and I mentioned where I got that information).

Best regards, Uli.

Guys, I don't have that problem. I can tell/hear when I start the engine whether it starts cleanly, doesn't start at all, or sputters because it's cold and one or more glow plugs haven't preheated. In the latter case, after a few revolutions and a little gas, it catches (and I take care of the glow plug system ).
In a diesel engine with a properly functioning fuel system, I would expect it to start running on its own after a few successful ignition cycles. The reason why the manufacturer included a minimum speed threshold for this is something I don't understand (it might be necessary for PD or CR engines).
A state between (1) = normal idling after starting, and (2) = not starting, where the engine runs roughly and can only be exited by turning it off, remains for me an unacceptable technical issue. A vehicle must be user-friendly to this extent. No operator of a machine, an airplane, or anything else would accept such an operating state.If the manufacturer had dared to address this issue in their instruction manual, they would have received a corresponding reaction from experts in the field.
hg
Herbert.

Hello fellow enthusiasts,

Here's the original poster chiming in again!

@Herbert: Du sprichst mir aus der Seele!

@DieselBär30X: Thanks for the link! But I would never have come up with the search term 'starter motor speed'...

And now, let's get to the facts:
Starting point: Engine warm (coolant temperature: 83.4°C), multi-connector disconnected from the ESP, starter motor activated multiple times for approximately 5 to 10 seconds each time.
Engine speed: The VCDS display fluctuates between 168, 210, and 252 RPM, with 210 being displayed most frequently. Therefore, I estimate the engine speed to be approximately 210 RPM.
Battery voltage: 11.0 V (measured directly at the battery terminals).
Starter current: approximately 160 A (initial value approximately 250 A).
This results in an approximate power consumption of 1.8 kW.

When you unplug the coolant temperature sensor, the engine starts much more readily and has a brief over-rev up to approximately 1500 RPM.
That's probably the discussed increase in starting fuel volume when the engine is cold, right?

Conclusion: Starter motor speed is too low, power consumption is normal (so no transition resistances) --> New starter motor ?

EDIT: Minimum speed: 300 RPM???

The prices are not cheap: AUDI: €320 (Austria), BOSCH: €245 (Austria).

Does anyone have a better source for an original quality starter motor with part number 068 911 024 F?

Best regards, Oldi.

Servus Oldi!

I had been searching for "500" and not anything else .

I would say that 210 RPM is a bit low, and something above 250/260/270 would be better.
As discussed throughout these pages, you now have the choice of buying something decent ("cheap" is NOT "affordable"!!!) or, alternatively, living with a 1-second longer warm-up time.
If you use cheap materials here, it might seem promising for a few months, but then it will likely become even more disappointing later... Decide for yourself whether you want to pay twice, get frustrated 15 times more, or do it right the first time .

You already know my advice on this. And if the coal absolutely has to be removed, I would suggest starting with the battery – it's a "cheaper" option and also more likely to work consistently.

Best regards from Munich!

Hi DieselBär30x,

How do I start with the battery???
It still has a healthy charge at 160 amps and 11.0 volts, and it's delivering the 1.8 kW specified in the starter motor specifications with 'clockwise' rotation.
I replaced this battery (of course, it's another good MOLL...) only about 3 years ago, and even then, this warm start problem already existed. With the new battery, it was only marginally better because the old MOLL battery was simply dead.

But regarding the starter motor: I certainly don't want to install just any cheap, low-quality part in my otherwise reliable Audi (so definitely no cheap, new parts). I clearly distinguish between 'affordable' and 'cheap.'
Either have Bosch/Audi replace the starter motor, or do it yourself, including removing the collector ring and rebuilding the starter.
I already have the high-temperature grease you mentioned (PLASTILUBE, which is also used on the back of brake pads).

Best regards, Oldi.

I've always been very impressed with MOLL products, and 3 years isn't that old.
However, it definitely makes a difference whether the battery fails at 11.0V or just 11.4V.

Okay, then get a starter motor from Bosch (still ask around with the dealers, maybe someone already has one in stock and would rather get rid of it than have someone else order it...). Or make it yourself.

Best regards from Munich!

I could get you a new Bosch starter for €170 plus a deposit of €60 .

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I have already used the high-temperature grease you mentioned (PLASTILUBE, which is also used for the back of brake pads)

.
That's not it. The grease shouldn't only be temperature-resistant, but also allow the bearings, etc. to run easily.
hg
Herbert.