VOLVO 855 TDI: Ex T5 Model for Sale

Hey everyone in this forum,

I've been a regular reader here for a while now, and I've learned a lot from this platform.

Sure, I also have some questions about the performance of my modified car. As you can see from the title, I converted a T5, which was originally a gasoline engine, into a TDI. I'm not sure if I would do it again. It wasn't exactly easy.
Now, I'm having the following problem with the 'new' one:
He's smoking.
He doesn't do it continuously, but completely at random, sometimes more, sometimes less. The described EGR performance issue also occurs occasionally, to the point where I can't see anything through the rear window. It runs best at speeds above 140 km/h, when the cruise control is set. Then there's no smoke. At 130 km/h or less, even with cruise control, I often have intermittent plumes of black smoke behind me, and sometimes a constant veil of smoke. The same happens when accelerating; sometimes everything is fine, and sometimes I'm almost embarrassed by the dirty machine. The error memory doesn't indicate anything about this. The Bosch tester only showed that cylinder 3 is receiving significantly more fuel than the others. Are those the clouds of smoke?
The TDI is from a car that was involved in an accident, likely a rollover.
I'm not really keen on just replacing things like the AGR valve or the fuel injectors without a clear reason. It costs a lot of money, and there's no guarantee that the problem will be fixed afterwards.
What other causes might explain this behavior?
What can I check to avoid unnecessary expenses, especially since the renovation itself was already quite costly?

'It also seems that the fuel consumption is higher than expected, at approximately 8.4 liters per 100 kilometers, according to the onboard computer. However, a quick calculation suggests this is reasonable (780 kilometers with 70 liters after the last refueling).'
However, I'm driving a vehicle that weighs 1.5 tons and has an automatic transmission and air conditioning.
It's still probably better than getting 100 kilometers with 11 liters of fuel.

I will definitely visit this forum again, hoping to find helpful answers.
Best regards from Bielefeld.

Peter.

Hi,

If the third cylinder is indeed receiving significantly more fuel (however that might happen), it is reasonable to assume that soot formation is the underlying cause.
Because a specific amount of diesel fuel requires a certain amount of air to burn cleanly without producing soot.
Therefore, if the amount of air remains the same but the amount of diesel increases, soot can be produced due to a lack of air.

Hi,

If the third cylinder is indeed receiving significantly more fuel (however that might happen), it is reasonable to assume that soot formation is the underlying cause.
Because a specific amount of diesel fuel requires a certain amount of air to burn cleanly without producing soot.
Therefore, if the amount of air remains the same, but the amount of diesel increases, soot can be produced due to a lack of air.

Hey Markus,
'Why are people responding so quickly? That would suggest that we should trust the Bosch service and just replace the injectors.'
I will still check the intake manifold for leaks and any debris, such as fabric, in the air filter housing beforehand.
Thank you for the response.
Peter.

Hi,

happened to be browsing the forum at that moment...

So, I'm going to wait for some other opinions before making a decision.
My rambling was of a more general nature.
Certainly too general to directly replace the nozzles!

If you already believe that the AGR valve is responsible for the soot, then why not disable it? It should be controlled in the same way in a Volvo as it is in an Audi, right? Simply disconnect the hose and the AGR valve will no longer function.

best regards

Hannes.

If you already believe that the EGR valve is responsible for the soot, then why don't you just disable it? It should be controlled in the same way in a Volvo as it is in an Audi, right? Just disconnect the hose, and the EGR valve won't work anymore.

best regards

Hannes

Hey Hannes,
Do you mean the hose on the pressure sensor of the EGR valve?
Will I still do it tomorrow?
Thank you.

Yes, that's the hose that goes to the pressure sensor of the EGR system. Simply disconnect the connection and seal the hose with a screw or something similar to prevent dirt from entering the vacuum system.

Best regards,

Hannes.

Yes, that's the hose that goes to the pressure sensor of the EGR system. Simply disconnect a connection and seal the hose with a screw or similar object to prevent dirt from entering the vacuum system.

Best regards,

Hannes

Hey Hannes,
Thank you to this forum, my diesel engine no longer produces excessive smoke. After cleaning the EGR valve, it starts much better, produces less smoke, and burns less diesel.
I should have disabled that thing much earlier.
So, I correctly interpreted the article about the AGr. It was, like the other technical articles, well-written and easy to understand.