N54 vs N55

[ajc]

What year did the N55 replace to N54? Is the N55 a reliable engine? Was the coils fixed with the N55?
I am looking at a 2011 135i.

[MLSavage]

The switch to N55 happened for 2011 model year.

Not sure of the coil problem you're talking about but the reliability appears* to be slightly better than N54, especially early N54. I had the same decision, buy the 2010 or wait for a 2011 N55 powered, I chose the 2010 N54 as the differences weren't big enough for me to wait (and pay more).

[alexmtl_135i]

The N54 had youth issues, not sure it's fair to consider it unreliable now. It's a tuner monster, you can get insane gains with just a tune, and they hold up very well.
The N55 didn't have much issues, but isn't so good to tune.

[Zombie1]

Originally Posted by alexmtl_135i

The N54 had youth issues, not sure it's fair to consider it unreliable now. It's a tuner monster, you can get insane gains with just a tune, and they hold up very well.
The N55 didn't have much issues, but isn't so good to tune.

I almost went with a 2011 with the n55 but after driving both I liked the n-54 power deliver better and found a 2010 auto for rather cheap compared to the 2011s and all new cars/motors experince growing pains,if your buying the car for performance which I think a lot of people do there's a reason bmws M division went with the N54 in the 1series M! either way you can't go wrong the torque on The n55 is amazing

[Jack Dempsey]

What are N54 & N55 stock boost?...

Thanks

[Zombie1]

Originally Posted by Jack Dempsey

What are N54 & N55 stock boost?...

Thanks

I think the n54 in the 335is and 1 series M has an overboost function putting boost up to 14.5 for a short time I believe these are correct don't hold me to it

[135Pats]

Originally Posted by Zombie1

I think the n54 in the 335is and 1 series M has an overboost function putting boost up to 14.5 for a short time I believe these are correct don't hold me to it

I don’t believe that to be the case, are you just talking about the kick-down switch you can depress if you go WOT? That doesn’t add power, it drops a gear to get you higher in the rev range. IIRC both the N55 and N54 top out at roughly 9psi bone stock. N54 turbos run out of room at something around 19-20psi midrange, not sure about N55s but I’d imagine it’s closer to 17psi. Obviously, you won’t approach those boost targets on a stock car.

Edit: apologies, I glossed over the 1m/is part of your post. Yes, those cars do run more boost, though 14.5psi still sounds a bit high to me.

[Bmwbreed]

Originally Posted by 135Pats

I don’t believe that to be the case, are you just talking about the kick-down switch you can depress if you go WOT? That doesn’t add power, it drops a gear to get you higher in the rev range. IIRC both the N55 and N54 top out at roughly 9psi bone stock. N54 turbos run out of room at something around 19-20psi midrange, not sure about N55s but I’d imagine it’s closer to 17psi. Obviously, you won’t approach those boost targets on a stock car.

Edit: apologies, I glossed over the 1m/is part of your post. Yes, those cars do run more boost, though 14.5psi still sounds a bit high to me.

I dont know if the 1m and 335is over boost function is 14.5 psi but I know it's advertised that at wot the over boost function allows the car to make370 pounds of torque for 7 seconds. So whatever that equates to in boost levels I guess.

[Haywood]

Does the 135is have the same overboost feature?

[BEAR-AvHistory]

Originally Posted by Haywood

Does the 135is have the same overboost feature?

No, it has more base boost than a 135i but no overboost function. Max torque for the 135IS is 317flbs/332ftlbs vs 370ftlbs for the 335is.

335is, 1M & Z4IS boost to normal/overboost 11.6/14.5psi. Stock N54 to 8.7psi & Stock N55 to 10. Not sure what the N55 PPK is.

[Haywood]

Originally Posted by BEAR-AvHistory

No, it has more base boost than a 135i but no overboost function. Max torque for the 135IS is 317flbs vs 370ftlbs for the 335is.

So, how do you like your 335is? Thinking about picking up a used one in Oct.

[BEAR-AvHistory]

Very happy with it, has 17K miles on with no problems. Based on some of the 335is guys I follow on the JB4/BMS forum they look to be very reliable.

[BEAR-AvHistory]

Was talking to Terry at BMS & he said the N55-PPK is worth 1-1.5PSI.

[ChristianReyess]

IM on a 08 N54, at 52k miles and I am starting to get stutter with drops power at WOT On Tune number 5 (JB4) I think its 12psi -16psi. They car stutters drops power and after about 30 seconds the check engine soon light disappears and the power delivery goes back to perfect smoothness.... its weird idk if the turbos are giving out or what! I think I am going to make a post about this... Yup I am!

[PA135i]

My turbos gave out at 49,965 miles. Dealer changed them out under warranty, along with the waste gates..etc. I was having some similiar issues.

Take it in now at 52,000 and they may replace them as good will. You are very close to warranty expire mile limit of 50,000.

[BEAR-AvHistory]

Originally Posted by ChristianReyess

IM on a 08 N54, at 52k miles and I am starting to get stutter with drops power at WOT On Tune number 5 (JB4) I think its 12psi -16psi. They car stutters drops power and after about 30 seconds the check engine soon light disappears and the power delivery goes back to perfect smoothness.... its weird idk if the turbos are giving out or what! I think I am going to make a post about this... Yup I am!

Plugs? With a tune 25-30K is good time for a change.

[Dackelone]

Originally Posted by BEAR-AvHistory

Plugs? With a tune 25-30K is good time for a change.

+1. First try new plugs (OE) and then start looking at your coil packs and injectors. Are all of your injectors the new design>? Did you have the recall done?(to check the injector part numbers).

[ChristianReyess]

Originally Posted by PA135i

My turbos gave out at 49,965 miles. Dealer changed them out under warranty, along with the waste gates..etc. I was having some similiar issues.

Take it in now at 52,000 and they may replace them as good will. You are very close to warranty expire mile limit of 50,000.

Hmm I'll have to look into this, and our turbos where extended to 10 years 100k miles, just an FYI!

Originally Posted by BEAR-AvHistory

Plugs? With a tune 25-30K is good time for a change.

Yeah that is what I was thinking. Any links to a good website where I can purchase?

Originally Posted by Dackelone

+1. First try new plugs (OE) and then start looking at your coil packs and injectors. Are all of your injectors the new design>? Did you have the recall done?(to check the injector part numbers).

I have no clue, I haven't even checked up, Ill have to call my service rep!

[BEAR-AvHistory]

You can get Bosch replacement plugs at the auto store. Same part number as the BMW plug but no BMW logo on them. Very good pricing compared to the dealer BMW labeled plugs.