[Jelle458]

I got my car to an aircon service and I asked if I could borrow their tester for my car, because I had some headlight issues.

The headlight issue has not been resolved but waiting for parts.

The tester I used was a Hella. I have my own Delphi (copy from ebay) which is not very good for this car. Worked great for the E39 but not really usable on this. It never told me anything was wrong with the engine.

The hella tester however wrote that the stepper motor in the intake was faulty.

I assume the stepper motor is refering to the 3 stage intake and the flaps that open and close depending on rpm.
These are referred to as valves on the danish website I want to purchase these from, which got me thinking. Does it actually have a stepper motor that I missed, or could it only be referring to these valves? I want to purchase the big and the small one just to make sure.

Since it's EU car I just assumed it is a 3 stage intake - is there a way I can check to be 100% sure?

The car idle just fine, but when I slam the foot down it seems like it stops firing for half a second, then I have full power.
I honestly don't know if that's just how bigger engines work (never had N52 before) or if it is because of these valves.
That is really the only thing, I got decent power, the low-end power is about the same as the high-end power of my old E39 with M52 2.5L engine, and judging from that I always figured it ran just fine. Only if I very quickly give it full power.
Once I hit 4.5K rpm I got no issues, which also leads me to believe they are just open all the time.

Can someone help?

[Suvorovo]

If your intake has Disa valves, then you have the 3 stage intake. The large disa valve is on the side of the intake manifold. The smaller one is underneath which you can see when looking through the ribs of the intake.

If you're going to replace them, which you should as part of 100k mile maintenance, go with OEM ($700 for both). Aftermarkets are known to fail prematurely. A broken Disa can throw the flapper pin axle into the engine.

[Jelle458]

Thank you for your answer. Car has been going 250K km, which is about 120K miles I guess, so it wouldn't be too weird then.
I am not sure what I am looking for when I look at the intake, I was hoping I could verify it is the 3 stage intake before ordering parts.
In Denmark the original parts go for a lot more than 700 dollars though, I guess because of the import I'm nearing 1000 dollars. The unoriginal I can get for about 300 dollars so that is highly appealing, but stuff other than air and fuel in the engine is not so appealing.

I'll try to figure something out, was just hoping I didn't need to disassemble the whole thing before getting the parts.

[Suvorovo]

Do not cheap out on disa valves and vanos solenoids!!!! You have a “performance” car and some parts need to be quality. I’ve never heard of aftermarket DISA valves lasting 100k. I’ve seen most cheap ones failing after 20k-40k. Also, to change the small DISA you need to remove the intake manifold which is about a 4hr job going slow. When you do that, it’s also recommended to replace the PCV system (300USD) and starter motor (250USD Bosch). You’ll have a brand new car once you do these maintenance items

Has some pictures for you:

https://eeuroparts.com/blog/disa-val...s-replacement/

Go to realoem.com, input your VIN and locate the correct part number for the DISA valves.
Most likely this:

https://www.fcpeuro.com/products/bmw...SABEgIOM_D_BwE