Cold start performance at -10°C: A NIGHTMARE

hello

It's likely an old topic that comes up every year and has probably been discussed extensively already.
On behalf of many Volvo drivers, I would like to ask for advice again – we are at a loss and don't know what else to do.

We're driving the AEL 5-cylinder engine from VW/Audi, and many people have really well-maintained vehicles – like me – but they're not exactly new anymore (around 300,000 km).

"I mean, my preheating system is working perfectly. Also, the ESP, injectors, etc., are well-maintained and properly adjusted. Many others report the same thing; a lot of money and effort is put into it – glow plugs, injectors, everything is replaced – but there's absolutely no change in cold starting performance."

Today I recorded the following videos: The car had been parked overnight in temperatures around -18°C, and when I tried to start it midday, the temperature was approximately -12°C.

First attempt using a branded battery, but it's old – it still lasts quite well, just doesn't have 100% power anymore. You can hear how slowly it's spinning.

http://www.youtube.com/watch?v=C8RIrMaklwQ

The battery was dead. Then I installed the two-year-old Arktis device, which had been fully charged overnight, take a look:

http://www.youtube.com/watch?v=0Eogl4mFN-M

At the bottom of the instrument panel, you can even see how old it is. Below the BC display, there's definitely ice inside.

Are there any clues, tips, or anything like that available? It seems from our forum that many people are experiencing issues with this engine. How does Audi handle it? It could even be related to the engine control unit – we have an MSA15.7 here. I think VAG uses the EDC15. Does it work differently/better?

I personally used to own a car of the same make that was very poorly maintained, but it started perfectly every time. The only difference was that it was an automatic transmission. Could it be that the starter motor is engaged differently or better in automatics?

Thank you for the tips.

best regards, uwe

Tip: Check the injection start! If it's okay, try adjusting the injection start time closer to the tolerance limit, but towards the "early" side. This should help with starting more reliably.

Thank you for the tip.

as far as is known and also configured accordingly .

Currently, the earliest possible time within the tolerance is +0.5.

"Thank you!!!"

Hello.

It would probably also be interesting to check the compression ratio when evaluating the engine's performance.

teileklaus wrote:

Would it perhaps also be interesting to look at the compression ratio when considering engine performance (KM Leistung)?

It might be...

But otherwise, everything is really great. The performance and overall condition are perfect, like new. Just the cold start issue – and that's happening with so many [vehicles/engines/etc.].

No, mine didn't put on a show like that.
However, the start of injection should be before, not at, the tolerance limit.
Besides the spark plugs (yes, I know), the starter motor speed should also be checked.

Quote:

The start of injection should be before, not at, the tolerance limit.

"Yes, we've had similar experiences with various (nearly identical) five-cylinder engines in the LT. If they aren't significantly outside of their tolerance range, they simply won't start when cold. It also seems that the five-cylinder engine barely starts if even one glow plug isn't functioning optimally (e.g., if only the regulating coil is glowing)."

Furthermore: Check the idle fuel delivery with a warm engine. If it exceeds 5mg per cycle, the pump needs to be readjusted. For example, if it shows 10mg instead of 4mg, there is a shortage of approximately 6mg in the starting fuel quantity.

Please disconnect the coolant temperature sensor and let me know what happens.
If the starter motor is worn out and not reaching the necessary speed, the engine won't start. Try to get it running. Also, please double-check the glow plugs, even if they are new.

Okay - thanks for the tips.

[Translating...]

[quote="vwSchrauber"]

Quote:

Des weiteren: Leerlaufmenge bei warmem Motor prüfen. Zeigt der mehr als 5mg/Takt an, so gehört die Pumpe nachjustiert. Zeigt er z.B. 10mg an, statt 4, so fehlen bei der Startmenge etwa 6mg.

anbei eine aktuelle auswertung bez. kraftstoffmenge beim startvorgang --> https://community.dieselschrauber.org/en/viewtopic.php?p=159824

uu. gibt es anhand der daten aufschluss ?

werde später nochmal bei warmen motor versuchen

danke

gruß uwe