N51 Driving average around 4K rpm in manual mode

[blackberryq10android]

Hi all,

Do you guys think our engine n51 or n52 for the others that we can handle a couple of miles one way of driving in manual mode (I have steptronic) around 4K revs per minute average? I ask because I get a bad smell whenever I do it at the end of the drive. I usually baby the car for the most part. How do your cars hold up? I prefer manual mode due to throttle lag that sometimes occurs with our automatic cars.

Thanks.

[02Pilot]

That's no problem at all. I make it a point to periodically get on the highway and run in 3rd for a while to get cylinder temps up and burn off some of the accumulated crap (and I'm not exactly gentle with the throttle in normal use - my car sees the redline every day it gets driven, just like every BMW I've owned).

The bigger question is what sort of smell you're getting and what's causing it. If it's a rotten egg/sulfur smell, the problem is that you're not getting the cats hot enough normally to keep them clean. If it's something else, describe it and we'll see if we can diagnose the issue.

[blackberryq10android]

Hello,

It is hard to describe but it is not an egg smell, I Can’t really describe it. However, it doesn’t always happen. Maybe it is due to the colder weather recently?

I usually don’t drive it hard. So you are saying it is better for the engine to keep the revs higher? I always presumed it is better to treat a car like you are steping on an egg shell by babying the throttle.

[printerror]

Manual N51 128i here, I keep it in the 3-5k rev range on a regular basis because it's just better. The only thing it hurts is your MPG, and if that bothers you, get a Leaf.

[02Pilot]

With an engine in good condition, properly maintained, and fully warmed, running higher RPM will increase fuel usage a bit, but by getting the cylinders and the oil hotter it will burn off contaminants, deposits (in the cylinders and on the pistons, and in the cats), and water (in the oil due to condensation). Driving gently, especially in an automatic, is not doing your car any favors. In older cars, blasting around for 15-20 minutes every now and again was known as an Italian tune-up, as old Italian cars reacted particularly poorly to light and delicate use, but ran far better when run hard. Modern cars aren't nearly as sensitive, but there is still a distinct difference in the condition of the internals from a car driven gently and one driven hard.

Drive the car good and hard a few times. If the smell persists, take it to a good BMW shop. If it goes away, well, maybe the car was just telling you it didn't like being babied.

[blackberryq10android]

Thanks for the insight. One last question, shouldn’t one let the car warm up before going over 4K rpm though?

[02Pilot]

Definitely. Drive gently for ~20 minutes to get everything up to temperature and go for it. Idling in the driveway is next to useless - driving will heat things up faster and you won't be wasting fuel and time.

[blackberryq10android]

Ended up having a coil go bad this morning. So the smell must of had to do with a coil about to break. I am now changing them all out for new ones

[Patriot_Pat]

Might want to check around the oil filter housing gasket, when mine went I found it because coolant started leaking a bit and I could smell the coolant burning. There's a belt right below the OFHG that doesn't like to have coolant dripped on it for long periods of time.

[chris_flies]

With my new rear end gearing (3.73) in my car, I cruise on the highway at 3000-3500rpm regularly, no ill-effects that I can see. I've actually gained a little fuel economy, the driving experience is better (feels smoother, has a little more power at that rev range), and the car isn't having any of the intermittent rough idle issues I had prior.