nailing the TDI, but why?

Hello specialists,

I'm having an acoustic issue with my V70, which I've owned for about 5 years. From the beginning, the TDI engine has been very noisy and makes a clattering sound, almost like a tractor.
I've replaced almost everything on the car: a vacuum pump, new injectors, new nozzles, all the belts, and it was adjusted by a professional mechanic (using diagnostic tools). Still, it never got any better.
"Okay, I thought, that's just how it is." Now I've driven the car for 100,000 kilometers, and it now has 280,000 on the odometer, and it still runs like the first day. It also smokes a bit, although many people have told me that's normal.

Okay, I thought to myself, "That's just how it is," and the matter was settled.

BUT:

Now I've bought a second car of the same model, and it's been poorly maintained; there's no service history, the oil is old, and the belts are worn out (all of which are being worked on or have already been replaced) - aside from that:

The engine has 255,000 kilometers (approximately 158,635 miles) and, despite poor maintenance, it runs smoothly like new and doesn't produce any black smoke.

How is that possible? Where could the cause of loud diesel noise come from in a well-maintained engine?

As I said, it's not an acute problem for me, just an acoustic one.

"Oh yeah, could a small adjustment in the engine control unit possibly be the solution? The soot might be explained by that."

I'm curious to hear your opinions.

best regards, uwe

Quote:

alle riemen und vom freundlichen eingestellt (förderzeugs....) - wurde NIE besser.

How do you know that they configured it correctly?
I've seen this happen several times with LT engines, where they run at around 15° vOT (valve opening timing) in idle.

Bei dem anderen, nie gewechselt - nie verfuscht.

However, the "nailing" sound (likely referring to engine knocking) doesn't quite match the Russian car's characteristics. This could be due to other causes, such as a leak in the charge air system or a faulty EGR valve, etc.

hello,

So, the master technician adjusted the thing according to the tester's settings. He doesn't really know much more about it either, which is correct.

I've tried pretty much everything regarding boost pressure, but I haven't found anything. The performance is also good – according to the dynamometer, it's over 390 Nm.

"But what's strange, and has been bothering me for a long time, is that the boost pressure is correct, but the LLK (likely referring to an oil cooler) is losing oil. I initially thought it might be cracked, but that can't be right if the pressure is normal - or can it?"

Having limited contact with specialists, and since there's no one locally here in southern Austria who can help, I still wonder: where does the oil come from in the automatic transmission fluid (ATF)?

some virtual specialists thought that this was normal .

"Thank you."
best regards, uwe

390Nm?

Hehe. Yes. Even more!

I had a fuel leak. The friendly Bosch service technician sealed the quantity adjustment valve and then adjusted it.
He then called me and asked how he should adjust it. He said he had adjusted it "pretty well," according to the inspection report, at a little over 400 Nm.

I was thrilled and said, "Yes, yes, that's fine!"

"Then, I experienced some jerking in the fifth gear at 1800 rpm."

I then had to go back to him, he adjusted something, and then it measured around 390; that's how the car started running better again .

I found the reason for this in the control unit; it's labeled "Kerscher."

Oh yeah, I'm getting a very good fuel efficiency with the car. My wife is driving it right now and she's getting just over 6 liters per [unit of distance - e.g., 100 kilometers].

When the car was adjusted to what felt like a "better" setting, the fuel consumption was even slightly better, but unfortunately, it wouldn't stay that way as described above.

Regarding the problem described earlier: The "strong" setting is a switch, and you can drive the car very, very gently. If my wife drives and I then suddenly accelerate – it's EXTREME – I can't even see the sun anymore.

The other one is an automatic and often runs at higher speeds without being forced to do so.

Could the soot somehow have affected the overall mileage?

best regards, uwe

How did you manage to get over 100 horsepower more than the standard output? What exactly was changed and modified? I heard about problems with the AEL (e.g., cylinder head) and that it's not even the best engine in its stock configuration.

It's just the chip – nothing else.

And I can only speak from the perspective of people who work with Volvo; we have very few problems with the engines – some failures are due to timing belts, but these are usually related to maintenance issues.

Generally, everything else works fine.

My car has almost 300,000 km on it. As I said, some parts have been replaced, but everything is original equipment. The engine runs great and has plenty of power .

But to go back to the fundamental question, which I'm not really expecting a perfect solution for, since the car is actually running well:

What makes the difference between a diesel engine and a gasoline engine? Why are diesel engines becoming less common in newer vehicles? Where does the "diesel knock" sound come from?
Why is the old tractor making so much more noise?


I'd rather clarify the fundamental question.

"Thank you."
best regards, uwe

Well, Mulle, you're right. That's a completely new aspect.

A standard chip should measure a little over 300nm or 320nm, I see. So why is mine reading almost 400?

Is the chip junk?

Perhaps the cause can be found there as well?

especially since the other one doesn't have a chip, and I don't find the difference to be *that* significant, so I don't feel like I urgently need one.

The problem is that the cars are different, or rather, the control units are different – otherwise, I could just swap them out.

The old version is MSA15.7, the new version is MSA15.8, AND then the WFS (presumably a software component) should be programmed into the control unit – is that correct?

"Thank you."
best regards, uwe

And one more thing to keep in mind: With a testing rig, you can measure everything... but measuring it correctly is unfortunately the real art.

I also find 390 Nm to be completely unrealistic.

Okay, I relied on the Bosch service for that. I'm not sure if their measurements were accurate or not.

The technician definitely made a competent impression.

best regards, uwe

What do your injectors say about their age? Are they also at 280,000 km?

hello,

The injectors have been replaced, specifically at 260,000 kilometers. Only the injectors were changed; the housings were kept. They were then tested and appear to be okay.

However, it hasn't changed anything at all, neither the noise nor the soot.

best regards, uwe