D5 (2005 on) Engine ticking/rattling noise

[toniln74]

Hi there,
I would really appreciate it if someone could help me.
I’m facing an engine problem-constant ticking, rattling noise. I suspect hydraulic lifters/tappets.
I apologize if the same topic has already been covered but I’m not so familiar with this forum. I’ll look for this issue here as soon as I have time ….I also apologize if my English doesn’t sound natural.
I’ve had the car for almost 3 months now-Volvo XC90 2.4 D5 185hp 2008.
I ‘ve been to several workshops (recommended as the best ones by friends) incl. two Volvo dealers(one here in Greece and one in Bulgaria). The first Volvo dealer in Greece after one hour inspection incl. VIDA, road test etc. told me that it was more likely to be faulty fuel injectors. Solution:to have them repaired if possible or changing with new ones which would cost me an arm and a leg. The second Volvo dealer in Bulgaria told me that this was a normal D5 engine noise because of the age/milage(2008 first registr.,262000km) and of course I couldn’t believe them. Three more workshops visited and the same verdict-injectors. The fourth one suspected hydraulic lifters.
Anyway, I had to narrow down the noise so I went to a specialized workshop dealing only with injectors. As soon as they heard the noise I was told it couldn’t be the injectors, it was more likely to be a mechanical problem. But I insisted on removing all the injectors and have them checked, cleaned and serviced. So they did. As a result-all of them were fine, almost within the limits according to the charts(I can send the results if s.o. wants to see them). No need to repair or change any of them. That calmed me down and 150 Euro flew away from my pocket.
I’m about to buy new lifters with rocker arms in order to change them all…BUT today again I removed the engine cover and began listening to the injectors with a big screw driver and then with a stethoscope. I’ve discovered that the 5th injector is making a bit stronger ticking noise but it is just one idea above the sound that comes from the other injectors .I don’t think this is a big issue. When I open the throttles I can hear that distinctive metal sound like rattling so I’m leaning towards lifters.
On the other hand before I bought the car I had it hooked up to VIDA and the guy said the fuel pressure in the rail was 15% higher than normal. Then in a month time when I went to Volvo they said the pressure was ok. Is there a fuel pressure regulator that is playing a havoc with me?
Is it also possible that one or more valves make that knocking?
I am in despair: I don’t want to spend any extra money one something that might be good and there is no need to change as I did with the injectors. Now lifters and rockers. It might turn out to be something else…
I have uploaded two videos on YouTube and I accept and I would appreciate any pieces of advice.
https://www.youtube.com/watch?v=3_XZ3yTOXEc

https://www.youtube.com/watch?v=lsC2bZckLNA

The car is running just fine: the engine is smooth, fast acceleration, good mileage on the high way and in the city.
One more question: I’ve found different brands of lifters for my engine but they have different length e.g.
INA, RUVILLE, KOLBENSHMITD-34.5mm;
STARK-34.7mm
SWAG, FEBI BILSTEIN- 35mm
Which size is the right one? In the shops they say either.How come, it makes big difference?
Is it good if I put new Kolbenshmidt lifters with INA rockers or they have to be the same brand?
Thank you in advance.
Best regards,
Toni