Golf 5 GT TDI smoking white

Hello,

I would like to briefly describe a phenomenon and gather opinions about it.

Approximately 2 weeks ago, I noticed white smoke (or possibly a lighter color?) in the rearview mirror while driving.
Immediately stopped and checked.
Bright smoke, with a sulfurous odor, rose from the exhaust pipes; it was not foul-smelling, but rather acrid.
After a few minutes of idling, the smoking stopped and everything seemed normal.
I was thinking about the regeneration of the DFP.

Yesterday (approximately 300 km later, without refueling in between), the phenomenon occurred again.
However, it lasted longer. To me, the interval seems much too short for the DPF regeneration process.
Admittedly, most of the races during that period were short-distance events.

The phenomenon can also be observed by noting that the engine is running during the smoking phase.
It reluctantly accepts the gas and sputters a bit.

The error memory was just read, and no errors were found.

Does anyone have any advice?

Regards,
gobedi

What about the usual suspects: What about the fluids like engine oil and coolant? Is there anything noticeable about their consistency or levels?

Regards,
Guste.

gobedi wrote:

Yesterday (approximately 300 km later, without refueling in between), the phenomenon occurred again. However, it lasted longer. To me, the interval seems much too short for the DPF regeneration process. Admittedly, most of the races during that period were short-distance events. The phenomenon can also be observed by noting that the engine is running during the smoking phase. It reluctantly accepts the gas and sputters a bit.

Hi,

"First of all, I agree with Guste. (Defective VTG turbochargers with filters are also a problem for other engine manufacturers, which causes this smoke.) Otherwise, the jerking and sluggish throttle response already indicate regeneration. 300 km can already trigger regeneration, and the regeneration cycles have been significantly shortened (to about 700 km). Depending on how much short-distance driving is done, more soot is produced, and the filter becomes clogged more quickly, which triggers regeneration. If there is currently a lot of ash in the filter, it will regenerate even more frequently. With a maximum fill level (regardless of the cause), the goal is to prevent the combustion temperature from becoming so high during regeneration that the filter housing melts."

Hello and thank you for the responses.

Oil and water appear normal.
The oil level is still in the upper middle range after approximately 9000 km; with my previous TDI, I had to top it up by this point.
The coolant is a nice pink color, and when the engine is warm, it's exactly at the maximum level.

I just drove 80 km on the highway. After that, I discovered something else:
There's something oily inside the exhaust pipes. It becomes sticky when it cools down.

.

I'll call the VW dealerships on Monday.

Regards,
gobedi

Could this be a type of grease? Furthermore, I once read in an Opel forum that on new cars, a pungent smell and white smoke can come from the hot exhaust pipe, which can partially melt the underbody coating (wax) and then vaporize due to contact with the hot exhaust stream. However, this doesn't really explain the residue you're seeing in the exhaust end piece.


IDKJ

That looks like coolant to me.
However, the new cars have the red coolant, right?

Deepgolf wrote:

That looks like coolant to me. Allerdings haben die neuen Wagen ja das rote Kühlmittel, oder?

It's probably safe to say that fat, oil, and coolant are unlikely to be present there, as the temperatures likely reach levels that would break down these molecules into their constituent parts and cause oxidation.

Hi,

Have you been able to find out anything?

I just had another thought: Are there any inorganic compounds that have similar properties and can withstand temperatures of up to 1300°C?

"I once experienced a situation where my diesel particulate filter (DPF) was clogged due to a faulty additive pump. After flushing it with water, the differential pressure returned to its minimum value. However, the car still emitted a slight amount of smoke, and the emissions test showed a turbidity of 0.2 (the engine typically produces a turbidity of 0.5 without a filter). The soot load increased only slightly until the next regeneration, which occurred after approximately 650 km, and then it didn't reach the previous levels."
Der Filter besteht bei mir aus reinem Siliziumkarbit, (welches eine Porengröße von maximal 5µm hat und bis zu 1470°C aushällt). Dieses Material hat eine sehr glatte Oberfläche, ein festkleben von Partikeln ist undenkbar. Da ich keine 250€ für einen AT FAP ausgeben wollte dachte ich über das Additiv nach. Das PSA Zeug besteht aus dem Element Cerium (welches für die 450°C Abbrenntemperatur verantwortlich ist) und aus irgendeinem Katalysator. Kurzerhand goss ist etwas verteieltes Additiv auf den Filter, was er gut aufsaugte. NA negative side effect was a beastly stench, as a portion of the material vaporized at an exhaust gas temperature of 400°C.
The addition of 100ml of fluid did not result in a measurable change in the engine's operating condition, but since then, it has been collecting soot perfectly again. The nozzles of the exhaust pipes are verschandeln again after 500km, except for the usual winter road grime.

What I'm trying to say is, perhaps your liquid is a type of storage catalyst, and the filter was pre-treated with it at the factory to make it catalytic, so that it can absorb soot. Maybe the filter has absorbed more than it can handle and is now expelling the excess.

"Any other liquids that I can think of would certainly not withstand temperatures above 1000°C. Well, the amount of catalyst in the filter is limited, so it's questionable where such large quantities would come from to end up in the exhaust pipes."

The fact is that I've experienced that the original catalytic layer on my device is being removed by large amounts of water, but it can be reapplied using household remedies.
The entire theory is pure speculation on my part, based on my own experiences, which don't entirely convince me, but which I consider the only plausible explanation. The exact nature of the catalytic storage function in the filters is very vague, and even the AU book from 2007 is very brief, and nowhere can you find information about the secrets of the coating or the manufacturing and maintenance processes. I have always received a replacement filter from the manufacturer every 80,000 km free of charge, which has always been a used filter that has been cleaned and filters very well.

Meanwhile, the whole story has dissolved into thin air.

After my vacation was over and I had driven some longer distances again,
The error, or whatever it was, has not occurred again.
The dealer mentioned that the problem might be caused by potentially poor fuel (sulfur) in combination with...
Short trips might have been the cause.

Here's what else could be said about that greenish stuff in the exhaust:
It was water-soluble and not oily, as initially suspected.

Regards,
gobedi

Hello,

A customer's vehicle recently had a similar issue, with a yellow-green crust on the exhaust pipe.
I initially suspected it might be coolant residue, but that's red, and the coolant reservoir was full.
It looks and smells sulfurous. According to the customer, a suspicious fuel additive is being used, and it's quite possible that sulfur is being added to improve lubrication.

Best regards, Rainer.