Hi everyone. I was wondering what this component is called in the engine compartment and right behind the engine cover. Can anyone help me, please?

The funny story: I used engine cleaner spray, however, I did not rinse it at all. It was last saturday.

Next day I drove 130 km, mostly on the highway. No problem at all. (I do not drive every day.)

Today I used the car in the city center appx. 8-10 km, mostly slow driving, less than 50 km/hr.

This component started to smoke, and I parked the car in the nearest possible place. Waited 10-15 minutes. The smoke disapeared.

I started the engine again, in idle gear, ran the engine 15 minutes. Nothing came.

2 hrs later, I drove the care back. Still no smoke. But I got the same smell.

I looked at workshop manuals, but could not find the exact component, so I could get an idea about what has been going on.

Regards...

Diesel particulate filter (DPF) and catalysator are there in somewhat combined unit. I guess it was related to dpf regeneration, thus not smoking later. Probably will smoke when it regens next time (burns soot in the filter). And to be clear, there should not be smoke in the engine department, the dpf (or the cat) is leaking.

Thank you very much @Skodaudi :-)) I remember now, after reading your reply, that I used a DPF cleaner, (0,3 liter, filled in to the tank same day as I used engine cleaner, last Sunday. I did so because I bought this car recently, second hand, I though it will improve the combustion/exhaust processes. In the label of the DPF cleaner, it says: "Specially developed for cleaning and regenerating particle filters and preventing filter blockage." Could that be something related to this, I wonder.

Some of the dpf cleaners work by increasing exhaust gas temperature and burning the soot in the filter that way, what could cause burning through / leak in the exhaust equipment. Other, I wud say better, dpf cleaners work by decreasing the temperature needed for soot combustion and dont increase the exhaust gas temperature. Do you recall what brand you used?

With engine cleaner, do you mean engine flush before an oil change?

As precaution I wud fill the tank with diesel to dilute the dpf cleaner.

Edited 6 June, 20256 Jun by Skodaudi

I am getting wiser. Thank you Skodaudi :-)) The engine cleaner is just a spray for engine compartment cleaning/washing externally - not a liquid that goes into the engine itself. Your description of DPF cleaners made 100% sense. I think I can get rid of the problem if I empty the fuel tank if the problem persists. The DPF cleaner I used is just a privat label (and cheap) but I could get this information, for the sake of curiousity: (translated via deepl.com)

SECTION 3: Composition/Information on ingredients

3.1/3.2. Substances/mixtures

NAME: Distillates (petroleum), hydrotreated light

IDENTIFICATION NOS: CAS No: 64742-47-8 EC No: 926-141-6 REACH No: 01-2119484819-18-0001

CONTENT: 60-100%

CLP CLASSIFICATION: Asp. Tox. 1

H304

NAME: 2-ethylhexyl nitrate

IDENTIFICATION NUMBERS: CAS No: 27247-96-7 EC No: 248-363-6

CONTENT: 5-10%

CLP CLASSIFICATION: Acute Tox. 4, Aquatic Chronic 2

H302, H312, H332, H411, EUH044, EUH066

NAME: Distillates (petroleum), hydrotreated light

Best regards from Copenhagen.

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I am grateful for you have devoted your time.

It is exactly those additives with nitrates that increase the combustion and exhaust temperatures.

With external spray cleaning it is also possible that the cleaning spray has dissolved oil or other dirt, that has then accumulated to dpf surface and started to smoke during a dpf regen (in this event, exhaust gas and dpf temperatures are also elevated for the regeneration) or because of the additive. This would be better scenario since then there is no actual damage at the dpf or cat.

Good morning. I just drove 70 km here in the morning, more than 50 km being in highway, and I went up to 130's. Nothing :-)) So, this was a one time burning off the clogs/residues. I am relieved. Have a wonderful weekend. God bless you @Skodaudi