Thick blue smoke on startup

Hello!
'Recently, there's been a lot of blue smoke coming from the exhaust when I start my Golf 3 TDI. However, once I've driven it for a bit and it's warmed up, the smoke disappears. This has only started happening now that it's gotten so cold. It also takes a little longer to start in this cold weather. Could it be that the glow plugs are starting to fail? I've never replaced them; they've been in since I bought the car, so they've already done 70,000 km. I don't know how long they were in with the previous owner. And is it a lot of work to replace the glow plugs? I've heard it's difficult to access them.'
Sure, no problem.

Regards,
Thomas.

Hello Thomas!

Increased blue smoke during a cold start could be a sign of faulty fuel injectors.

Best regards, D.

I'm also experiencing the same blue smoke. I had the injectors checked and cleaned, and they're all okay. Only the third one has reached the wear limit of 170 bar with its opening pressure.

I'll wait and see if it gets worse.

Thomas76 wrote:

Could it be that the spark plugs are slowly starting to fail?

I've never replaced them. They've been in since I bought the car. They've already done 70,000 km for me. I don't know how long they were in with the previous owner.

Hi Thomas,

If you could tell us something about the total mileage, the answers would have a higher probability of being correct .

Hello!
So, the engine now has 210,000 kilometers on it.

Regards,
Thomas.

Thomas76 wrote:

So, the engine now has 210,000 km on it.

Hi Thomas,

Regarding mileage, both worn nozzles and faulty spark plugs can cause blue smoke.

If the engine runs unevenly for the first few revolutions immediately after starting (and this is more noticeable the colder it is), then at least one glow plug is likely faulty or has a resistance issue in its wiring.