Cold Start Problems: Are They Normal?

Hello,

I drive an Audi A6, manufactured in 2002, with a 2.5 TDI engine and a Multitronic transmission.

Since it's been really cold outside lately – below freezing temperatures – he has trouble starting in the mornings.
after the second organ note - and it's emitting a lot of blue-gray smoke from the exhaust.
However, this only happens when starting the engine; afterwards, it's more like normal smoke until it warms up a bit.
It happens every time when the engine is cold – it's not noticeable when the engine is warm or slightly warm.

In my opinion, an idle speed of under 1000 RPM in the morning, when the engine is cold, is acceptable.

Unfortunately, I can't say for sure if it's leaking oil. When I pull out the dipstick, it looks the same as it has for the past 1-2 weeks – there doesn't seem to be any noticeable loss.

What could this be – or what further information is needed?
Thank you.

I would start by checking the glow plugs. Use a flashlight, not a measuring device.

christians wrote:

I would start by checking the glow plugs. Use a flashlight, not a measuring device.

Headlight bulb?

Connect an H7 bulb with two wires, connecting one end to the positive battery terminal and the other to the glow plug. If the bulb lights up, the glow plug is usually okay.

Okay, let's test it out.

Can the spark plug be damaged by something like that?
"Sorry, I'm not an expert when it comes to spark plugs."

Can the spark plug be damaged by something like that?


No, it can't. 12 volts will always remain 12 volts, whether through an H7 bulb or via a relay from the control unit.

Caution.

"That's no longer true for everyone. The newer TDIs (e.g., my 2.0 PPD with 170 hp) have different glow plugs that are designed for 4 volts. However, they are also monitored by a separate control unit that will indicate if a glow plug is faulty."


However, for the 2.5 version mentioned here, the "lamp method" can still be used.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

"@dieselmartin: Thanks for adding that information, but even a 4-volt bulb should be able to handle about 10 amps, while the 12-volt 55W lamp provides just under 5 amps, which is less at the Gk (presumably referring to a specific connection point)."
It just burns a little brighter with the 4-volt candle.
Just don't apply 12 volts directly to it, especially when the battery management system (BMS) is connected .

"@dormelchen: Don't forget about the fuse."