Cold Start Issues at -10°C: A Nightmare

hello

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

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

"I mean, my preheating system is working perfectly. Also, the glow plugs, injectors, etc. are well-maintained and properly adjusted. Many others report the same thing; a lot of money and effort is put into it, with glow plugs, injectors, etc. being replaced, but there's absolutely no change in cold-start 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 this afternoon, the temperature was approximately -12°C.

First attempt, using a branded battery but it's old - it still lasts quite well, but it's not at 100% capacity 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, 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, it's definitely icy inside.

Are there any clues, tips, or anything like that available? It seems that, according to our forum, 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 model that was very poorly maintained, but it started perfectly. The only difference was that it was an automatic. So, is the starter motor engaged differently or better in automatic transmissions?

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 improve the starting performance.

Thank you for the tip.

as far as is known and also configured

Currently, +0.5 is the earliest possible time within the tolerance, according to my information.

"Thank you!!!"

Sure, here is the translation of the text from German to English:

"Hello"

It would probably also be interesting to check the compression ratio when evaluating the KM performance.

teileklaus wrote:

Would it perhaps also be interesting to look at the compression ratio when it comes to KM performance?

It might be...

But otherwise, everything is really great. The performance and everything else is perfect, like new. The only issue is the cold start – and this happens 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 the same experience with various (nearly identical) five-cylinder engines in the LT. If they're not significantly outside the 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 working optimally (e.g., if 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 the starter motor running. Also, please double-check the glow plugs, even if they are new.

Okay - thanks for the tips.