N54 feels hesitant in higher rpm

[Bland]

Hello, I've looked around and couldn't find any answer that fit what I think I'm feeling. I bought a lower milage 1M not too long ago that has been very well taken care of. There's literally zero rock chips in any of the factory paint. Since this forum is more popular I figured that it was better to post here as the engine is not too different than the 135i's n54.

The car is fast. The amount of power it makes throughout seems on point. The situation is that I feel like the engine doesn't want to go past 4K. It feels almost like i'm wringing out an old engine as in you sorta cringe when you open it up a bit. It makes the power but it doesn't feel like it likes it. Feels like there's a large airway restriction. I've yet to go wot from a stop but the lower rev range doesn't feel bad. It could be all in my head but I've been heavy footed with many cars including turbos and never have I felt like I could be hurting an engine. I've never driven another n54 or n55 so I don't know if this is just normal but I've heard the engine described as eager in reviews. That's not exactly how I'd describe it at this point.

The entire time I've owned the car the max the temp has been outside was 50F. It does seem a bit happier after its warmed up and I've always kept revs low when cold. Takes a long time (>10 mins in colder weather) to warm up which I've read is normal for the M. It's definitely not the dsc and the car passed inspection at 2 different dealers without any problems.

I'm not too knowledgeable of this engine but here are some ideas I've had as to what could be causing it. My guess is I have no idea wtf I'm talking about:
The wrong oil was put in and it's just too viscous in this weather.
The car was never pushed very much in its life and needs to be broken in a bit more than usual due to valve seating, piston rings or whatever else should happen as an engine is broken in..
Gas pedal takes more pressure than I'm used to? Just crazy idea that pooped into my head.
Boost/Vacuum leak/charge pipe.
Vanos solenoid
Used car psychosis

Either way I love the car. I specifically went to the bmw dealer the day they got the first 135i brochures in. I took a lot of dumps drooling on that thing and am more than happy to finally have a 1 of my own.
Thanks!

[John_01]

Why not enquire about getting it run on a Dyno. Its the only way you would really know if the power curve is normal or not.

[mike@x-ph.com]

Post a datalog and we will have a better idea of what is wrong.
It is normal for an N54 to lose power after 6k rpms.

[Dackelone]

Have you checked the basics like: fresh oil change(with the proper LL1 oil!), clean air filter, fresh spark plugs ?

N54/N55's only make power until 6K rpms. Really 5,500 rpms and then power falls flat on its face. Unless you have a tune running more boost.

Someone could have used 10w60 ///M oil instead of the proper LL1 oil(0w30, 0w40, 5w40 or 5w30 bmw oils) on the car's last oil change. Or you could have a boost leak somewhere. Look for oily hoses under your hood.

[Bland]

Thanks for the ideas. I'll look into some dyno time soon as it would be nice info since I never experienced the car new. With the recent poor weather and without having any power in my garage I haven't had a chance to thoroughly inspect the engine bay. I wouldn't say that I'm experiencing power loss, though I only have one perspective. I've driven cars before that were happier in higher rpm than lower and that's not how it feels. I'm not talking about high rpm more like anything past 3,5k. It did recently have an oil change with the correct 5w-30. I'd like get a datalog but I don't know anyone with any of the required equipment. Afaik that's the only way to download it.
I'm assuming that under 20K miles is too early for carbon build up. Depending on how it was driven it may not be. Anyone heard of getting a dealer to scope it at a lower milage?

[135Pats]

Originally Posted by Bland

Thanks for the ideas. I'll look into some dyno time soon as it would be nice info since I never experienced the car new. With the recent poor weather and without having any power in my garage I haven't had a chance to thoroughly inspect the engine bay. I wouldn't say that I'm experiencing power loss, though I only have one perspective. I've driven cars before that were happier in higher rpm than lower and that's not how it feels. I'm not talking about high rpm more like anything past 3,5k. It did recently have an oil change with the correct 5w-30. I'd like get a datalog but I don't know anyone with any of the required equipment. Afaik that's the only way to download it.
I'm assuming that under 20K miles is too early for carbon build up. Depending on how it was driven it may not be. Anyone heard of getting a dealer to scope it at a lower milage?

Some thoughts....

1. Numerous means of pulling a datalog. Any tune will do it (JB4, Cobb, PROcede lol, OFT lol, etc). You could also use a Bavarian Technic cable (BT Cable), or any number of standalones. If you can find a Cobb user near you, you can have the car ready for data logging within an hour, with no physical labor required at all.

2. Everything about a stock N54 is geared towards off idle torque and minimized turbo lag. Torque comes on very quickly down low, and makes the stock car feel faster and stronger than it really is. The head was designed with this express purpose in mind, it doesn't flow well and really was not BMW's best work. The stock wheels and housings are extremely small, and further exacerbate what you are feeling. A stock turbo N54 has no business being above 6K revs, ever.

3. At 20K you could absolutely have carbon buildup. It's a DI motor with an ill-conceived internal PCV system. The valves get messed up in a hurry.

[ilikebmxbikes]

my n54 pulled until 5800rpm, as others noted, get a dyno or do some logs.