Turbo longevity N54 vs. N55

I am close to placing an order for either a 335i or a 335is. One factor that has recently come up in another forum is the longevity of the turbos. Does anyone know how long the N54 turbos are likely to last before needing replacement? Any idea how the single N55 turbo is likely to hold up vs. the N54 twin turbos?

It's a bit unnerving when club members say that they would not own a 335 that is out of warrantee. Typically I keep my cars well beyond the warrantee period and only drive about 6000 miles a year. I'm now beginning to ask myself whether I should even be buying a turbo-powered car. One alternative might be a CPOed M3 for about the same price (about $50,000).

On a separate issue, I am about to buy the car for ED from Joern Esser at Passport BMW in Maryland. He is not the lowest bidder, offering a price that is about $1000 over invoice. The low bidder is only about $200 less and is affiliated with a dealership that does not have a good reputation in the Washington DC area. Based on the good review that someone posted for Joern I just decided to give him the sale.
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No one including BMW is likely to be able to tell you if the N54 or N55 turbos will have a longer lifespan. The reality is turbos normally last quite awhile. The N54 engines had more wastegate rattle issues than actual turbo failures, which are rare. The N55 has not been in the market long enough to have much historical record to work from. Personally I would not have an issue with either engine's design.

My reservation with buying any BMW model with either the N54 or N55 engine however is that BMW does not seem to have cured the N54 HPFP issues after five model years. The N55 engine uses the same HPFP as the N54 engine and it seems like there is a new HPFP part every few months or so. Each new HPFP is touted as being "the cure" but it never seems to actually be "the cure". There have been forum posts that BMW is planning a worldwide HPFP recall to properly repair the N54 powered models but I wouldn't hold my breath...

I believe in public disclosure of known defects so I'd advise any consumer to check nhtsa.gov for safety defects on BMW models, especially the N54 powered x35i models from MY 2007 - 2011. Then you'll know what to expect regarding safety and defect issues.

As far as dealers go I'd gladly pay $200 more to purchase from a dealer who values my business, is competent, responsive and who treats me with respect. Supporting a bad dealer does nothing to weed these folks out of the system.

In reading around the various forums, turbo failures seem to almost always be associated with tuner loads to the ECU (JB, other). I can't really recall more than a couple of turbo/wastegate failures not in that category.

Anectdotal, only, of course.

If you've driven both models and can't decide which to buy then most likely neither is the right car for you.

If you're deciding which dealer you'll purchase your new $50,000 car from and it comes down to a $200 difference in pricing as the deciding factor rather than which dealership you're most comfortable doing business with, then a BMW probably isn't the right car for you.



The driving experience in the 335is is so different from the normal 335i that your choice should be fairly obvious.

If Wal-Mart sold BMWs for less than your local dealership, would you buy yours there? I think you made the correct choice by going on the reputation of the salesperson and the dealership. With any luck, the salesperson will remember the $100 he made selling you the car if you ever have a problem where you'll benefit from having someone on your side who actually cares about your welfare.

Your comments about the driving experiences being so different may explain why I don't remember feeling the same passion for the 335i when I drove it. I liked the car and would certainly be happy with it but it just didn't stir up the same feelings as the 335is. I discounted that "gotta have" feeling because I haven't driven a 335i since last fall so it is difficult to directly compare it with the 335is. Unfortunately, none of the dealers in the Washington DC area currently have a 335i coupe with a manual transmission.

When I took the 335is for a test drive the car clearly stirred up a "passion in my loins." I'm not exactly sure what it was about the car - it just seemed to fit like a glove. The seat position, the short-shifter and the steering wheel felt just right. And the acceleration was exhilarating.

I am not sure about the loud exhaust note. Yes, it was great fun winding through the gears but I wonder if that assertive sound will become annoying in everyday driving. In fourth gear at partial throttle the sound was fine so my guess is that it would be acceptable at highway cruising speeds.

Driving the 335is was like meeting a woman with whom I have instant chemistry. Rational thoughts like, "Would be be a good mother for your future children?" get tossed aside.

I probably should drive a 335i again for comparison but, based on this new revelation, I'm now almost completely sold on the 335is. Actually I've been leaning that way all along but feel a bit guilty. I should have outgrown this "hotrod" stuff long ago - I'm turning 73 in October.

Nonsense. By your symptoms it is clear that you, sir, are a recovering car guy. Known in British medical circles as cranial petrolitis or "petrol-head syndrome," it is a congenital condition believed to be caused when chromosomes one through six coil into cylindrical shapes during meiosis. Symptoms typically manifest with puberty, peak in late adolescence to early adulthood and never fully subside--though there are many recorded cases of complete remission brought on by marriage, child-rearing and long-term exposure to boring transportation appliances. The condition is not life-threatening. In fact, the majority of sufferers lead full and healthy lives, marked only by a propensity to grin like an idiot and/or burst into embarrassing, immature fits of giggling when exposed to a puzzling and wide variety of sensory stimuli, including but not limited to: curvy sheetmetal, petroleum vapors, lateral acceleration forces, high-frequency valvetrain whine and roarty, snorty exhaust noises.

So double-up the Poli-Grip on the uppers, take a hearty swig of Geritol and Metamucil, slip on the white buckskin driving loafers and get out there and DRIVE that sucker!

Actually I still have all of my original teeth - and a 55 year old girlfriend!

I finally located a 335i coupe and drove it this afternoon. BMWCCA1 is spot-on. The driving experience is very different between the two vehicles. I worried about the exhaust note being too noisy on the 335is but the 335i is too quiet. It's actually quieter than my Lexus SC300 coupe (with 5 speed manual). My Lexus has a pleasant, subdued growl; the 335i has nothing!

The dealer had a 335is on the lot with the DCT. I didn't bother driving it because of the transmission but I did start the engine and revved it to 4000 rpm. Yes, the exhaust is loud but I prefer it to the 334i lack of sound. My guess is that in normal, light-footed driving it will be exude mild, throaty sound.

The other feature that grabbed me is the 335is short shifter. I suppose that isn't hard to modify on a 335i but why do it if the factory will do it for you?

The last concern is the N54 vs. the N55 turbo. BMW must have a good reason for replacing the N54 turbo, which implies that the N55 product is superior. However, i get a 4 year warrantee and can extend it just before it runs out. By that time the N54 turbos will have been around for 8 years and their longevity record should be clear.

This is probably all rationalization on my part. My head tells me that the 335i is the logical choice but deep inside I want that 335is. It stirred up feelings in me that I forgot I had.

Screw the cost; I want that car!

Atta-a-Boy!!!!

It is what it is... If it makes you happy go for it.

See? Car guy. Told ya!