2.0 TDI (BKD) Smoking in Stop-and-Go Traffic

Hello,

Our Seat Altea 2.0 TDI is emitting smoke in stop-and-go traffic. Otherwise, the engine runs normally with full power.
At Seat, they found no fault and claimed that I had had the car "chipped" (modified with aftermarket software), which I have not.

It's probably clear that diesel fuel is evaporating, but the question is, why?

Thank you in advance.

Hello,

smell the exhaust and determine what the smoke is made of.
- Diesel (extremely bad, as it would indicate a faulty PD unit and the engine would run very poorly).
- Coolant -> What does the coolant level in the expansion tank indicate?
- Engine oil -> usually indicates turbocharger damage.
- If available and active, the auxiliary heater (standing heater) may also produce smoke.

Best regards, Rainer.

Hello.
This is likely the same problem I'm experiencing. So, it's not diesel, but oil, with a pungent odor. Please read my (sometimes older) post: https://community.dieselschrauber.org/en/viewtopic.php?p=246347#246347
Especially my more recent additions.

Regards,

Andreas.

The pungent smell comes from poorly burned diesel fuel, not from burned motor oil. You can easily distinguish the two smells.
hg
Herbert.

Hello...

Have you ever looked at the engine case ventilation?
"This thing tends to get really muddy quite often, especially if you frequently ride in urban areas..."

Exhaust Gas Recirculation (EGR) return pipe.

Both can be done quite quickly.

As my colleague already mentioned: Does he need coolant?
Starting behavior in the morning? -> If it starts poorly, you might have a hairline crack on the intake side -> not good -> replace the cylinder head.

If it's only losing coolant, the prime suspect is usually the EGR cooler (-> replace it). If that's not the issue, then suspect a crack on the exhaust side, like mine had. In that case, add two cans of "radiator sealant" and that should fix it. Mine has been running like that for 200,000 km, and now has 402,000 km on it, including a chip tuning to about 175 horsepower.

Otherwise, I would take another look at the LLR (likely referring to a specific component or system). I would also measure the diesel pressure of the tandem pump and check the oil level more frequently. Eventually, the tandem pump will fail, and then you'll have 10 liters of oil and diesel mixed together, resulting in a real self-ignition problem.

Hope I was able to help you.
Have a nice day.
Manfred.

Hello Manfred, thanks for the tips. But I've actually been dealing with this for quite some time already.
The expansion valves were/are completely clear on both sides. There is no coolant loss, and the engine starts and runs normally.
If a hairline crack in the cylinder head is responsible, it would have to be located between the intake side and an oil channel. Because the previous TDI engine (the one that smoked heavily) also always had noticeable idle fluctuations. This indicates that something was entering the combustion chamber, and in my opinion, it was engine oil (it also consumed more than usual, but still moderately).
So, after a long search, in my opinion, only these two latter causes remain, with the tandem pump being my "favorite." And I will definitely look into that one when I have the time.

Hello,

Have you ever replaced the PDE wiring harness? It doesn't necessarily last "forever"... and considering the age of the vehicle, that might be the case.

SG
Manfred.