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New 335d- engine braking, break in period?

6K views 13 replies 12 participants last post by  CALWATERBOY 
#1 ·
Hi,

I just purchased a 2009 335d (white, premium, sport, ipod, nav) over the weekend and had a few questions. Bear in mind this is my first BMW, first diesel, and first NEW car in general. The car is excellent and I really enjoy idrive and the ipod and phone integration in the car.

Engine braking: My previous cars just coasted to the end when I let off the throttle. I can definitely feel the engine braking, especially when it downshifts while slowing down. Is this normal? Is it a diesel or turbo thing? It seems like it would be less fuel efficient for the engine to do this, but I doubt that's the case.

Break in period: I'm trying to drive it easy still (only have 120 miles on it) and pretty much keep it below 2500 RPM. The car has so much torque, you can just live in the 1200-2200 RPM range or so. On a morning commute through Los Angeles with frequent slow down/speed up, I often sit at 1500-2000. Should I try to vary the engine RPMs more than by a few hundred RPMs? I honestly would have to manually downshift or hit the gas hard to get the RPMs above 2200 or so.

Well, thanks for any help you all can provide. As you can tell, I'm pretty new to this. I am really enjoying the car and can't wait until the break in period is complete so I can have some fun with it. For anyone interested in purchasing one, the engine is louder than I first thought and has a bit of the diesel noise to it. At a stop or low speeds I can hear it and it sounds like a big truck engine (just the quality of the sound, it's not that loud). I like the sound, personally, but don't remember hearing it while test driving since I was concentrating on all the other aspects of the car. So far, getting a bit over 26 MPG in daily commuting (stop and go/city for maybe 50% of the time), but that includes a good amount of engine idle time at the dealer.

Thanks!
 
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#3 · (Edited)
Congrats on the purchase! It is an awesome car, just got mine on saturday as well!

Per the manual said:
Up to 1,200 miles drive at varying engine and road speeds but do not exceed 3,500 rpm or 93mph. Avoid full throttle operation and use of the transmission's kick-down mode.

After 1,200 miles engine and vehicles speeds can be gradually increased.
Kick down mode is the button at the end of pushing the throttle all the way down (thus pushing it completely to the floor). You really should be fine as long as you keep it within those guidelines, if you go over once dont freak out, it is just what is best for breaking in the parts.

As far as engine braking, that sounds normal to me. They are made to work like that and it should be no problem. When engine braking you are not using any fuel as it is cut off plus it saves on brake wear. With a Manual transmission it is used a lot in fact and now many automatics with better torque converters are using it to a certain extent as well when you let up off the throttle.

Around page 114 in your manual details all the break in and some engine braking/fuel saving tips.
 
#4 ·
I assume it is an auto / auto paddles (you said "it downshifts.")

The BMW autos use a different programming than most that you are used to (and that I am used to.) When you step off the throttle, the BMW will leave the car in the gear you were in (still connected to transmission by torque converter) while most other autos will upshift to highest gear, which essentially feels like you are in neutral. It is kind of a compromise either way -- this way you can get back in the power zone to blast out of turns quickly, but it does create a weird engine braking sensation. When I drive a BMW loaner (I have MT) I always think it feels "funny" relative to a standard auto that you would get at Hertz etc.

Break in technique -- well, let's just say there are many opinions on this, and it is hard to really say what is best because it is simply difficult to prove any association between a given break-in technique and engine longevity. Some people will get all hot and bothered about this too (as you may find out.) :rolleyes: If anybody is too much of an evangelist, take their opinion with some NaCl.

The short answer is: it probably doesn't matter. Your engine should last a long time, and the failure points will probably not be related to break-in technique.
 
#6 ·
The engine braking you are feeling is due to the higher compression ratio of the diesels. I'm on my 3rd, first BMW and they all respond the same. It is just a lot more noticeable than a gas engine.
 
#7 ·
Hello and Welcome :)
 
#10 ·
Thanks to everyone for their replies. I'm definitely feeling the love!
I took some pics the other day but haven't gotten them off the camera. Nothing fancy, but I'll post some soon.
Thanks for the info on the transmission/engine braking. Like neapolitan said, all the cars I've driven before have been different, feeling like I'm coasting in neutral when off the throttle. I see how keeping the car in gear could help with performance.
Grentz thanks for the tip about the kick down mode. I was wondering what that was when I read it!
I guess I feel better about being a little less conservative with the car now too, since the manual says 3500 is the limit... I've been keeping it below 2200 or so, but I guess I've got more room to play with. :thumbup:

Thanks again!
 
#12 ·
I figured it was better to resurrect an old thread than starting a new one.

I bought a 2010 335d last week. My prior car was a 2007 335i with sport pkg. There is a big noticeable difference in engine braking between the two. My 335i would sort of coast when I lift off the accelerator, but the 335d slows down much quicker. I'm glad it's the norm for a diesel.

I'll post pics of my current and previous cars asap.

Thanks
 
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