Advise needed on 2012 4 cyl 28i

vinman · Post by **vinman** » Wed Nov 23, 2022 10:40 pm

Hello,
I am looking to purchase a 2012 28i manual trans with just over 100k. It has had two owners. No accidents. $18k

I want a stick and a hard top; I just would like thoughts on the 4cyl turbo. 2012 being the first year to market, and it's been 10 years, I figured someone would know if I should stay away from this model year.

Besides any problems I would also like input on 4 vs 6 preferences from those willing to share.

Thanks in advance,
Vin

B21 · Post by **B21** » Wed Nov 23, 2022 10:48 pm

The one issue with the N20 engine that powers your car is that pre 2015 the camchain tensioner and it’s associated parts can fail..badly…

At 100k there is significant risk that your luck may ..maybe may run out..

It’s a Russian Roulette issue many don’t but quite a few do go pop..

If the car is great in all other aspects then budget 1,500 USD to get it replaced sooner rather than later.

Otherwise a N52 powered 30i may be your bag.

javis20 · Post by **javis20** » Wed Nov 23, 2022 11:07 pm

That price seem pretty high. I bought my 2011 3.0i auto with 32k miles and M-Sport package and adaptable suspension for $20K

Mr Tidy · Post by **Mr Tidy** » Thu Nov 24, 2022 12:01 am

Welcome to the forum OP.

Prices in countries with prices in $ tend to be very different to UK prices in £!

But B21 knows all about the N20 engines.

I'm on my 4th N52 (albeit in an E90 3 Series) that is on almost 120K miles - it runs really smoothly and pulls strongly.

vinman · Post by **vinman** » Thu Nov 24, 2022 1:51 am

Thanks guys for the replies...
I will see if there is a maintenance record to see about the chain.
There were two previous owners. The price under the carfax website says that it’s almost 5k below book; I definitely will continue to search.

Ok so what’s the N20 and the N52 designation mean? I did some reading on the car and driver website but I don’t remember any mention of N#s.

Are Z4 with manual transmissions more expensive than automatics?

Thanks again everyone.

B21 · Post by **B21** » Thu Nov 24, 2022 10:22 am

N20 is the later 4 cylinder turbocharged model…

N52 was the preceding 6 cylinder normally aspirated model.

The N20 and N52 came with 6 speed manuals or the N20 had the 8 speed ZF8HP box whilst the N52 could have the 6 speed ZF6HP

I doubt that the N20 you saw had it’s camchain done..if it did then it should then be trouble free , hopefully..one US N20 Z4 has gone past the 500k mile mark with no issues.

Pricing wise for a N20 you would expect to pay a premium for an auto..for a N52 pricing is not so obvious..

N20 cars tend to have a better spec than N52s simply as BMW stuck more goodies on models later in the production life.

vinman · Post by **vinman** » Thu Nov 24, 2022 1:05 pm

Wow...you seem to know this car inside and out. Thanks. I appreciate your help. I hope to take it for a ride tmrw.
Happy Thanksgiving to you and your family; God’s very best to you.

B21 · Post by **B21** » Thu Nov 24, 2022 3:13 pm

vinman wrote: ↑Thu Nov 24, 2022 1:05 pm Wow...you seem to know this car inside and out. Thanks. I appreciate your help. I hope to take it for a ride tmrw.
Happy Thanksgiving to you and your family; God’s very best to you.

I had a N20 powered E89 for 5 years..I chose to replace the cam chain subsystem for peace of mind…my car had about 40k miles on it at the time…there was no obvious damage but…

I had the ZF8HP auto box and re-mapped it to 275 BHP then with a bigger turbo to over 300 BHP and 450 nm torque…

It was a great car…well balanced and enough go to keep up with anyone I came across..good handling as well..

Having said that all E89s are great cars IMHO..

vinman · Post by **vinman** » Thu Nov 24, 2022 5:06 pm

Ok, you got me thinking now. So the e89 with N54 would be what you would recommend? And I could use some help in deciphering what engine is in the cars that I am looking at. Besides it being a z4, how can I narrow my search to get a stick, hard top and the 'correct' engine; until you mentioned e89 I had no idea what that was in reference to as well as the N20, N54...etc. How do I know what engine is in each car that I look at online? Is that designated in the model name or in the vin#? Thanks from this very green newbie!

N4LLY · Post by **N4LLY** » Thu Nov 24, 2022 5:22 pm

The N20 E89's 18 / 20 / 28 are all exactly the same engine. Just at a different Tune stage.

You can re-map a 18 and get 28 performance without issue's. Looking for a 20 may give you a much better spec'd car.
It worked for me

vinman · Post by **vinman** » Thu Nov 24, 2022 5:48 pm

So I really appreciate your feedback but humbly request less Greek ...sorry...I’m not a car guru by any means. I do the maintenance on my tundra and I’m just starting my journey on the z4. So most of the nomenclature of what you wrote doesn’t mean a whole lot to me in my search of a vehicle. Meaning I see there is a 4 cyl and a six and then diff generations; I’d like to know how I know I’m looking at “e89” & a “18,20,28” or a “n20” vs a n54,n55 etc.
I guess I’m not following how one deciphers what I’m specs I’m looking at when I first glance at a listing of a z4 search. Thanks...

Ole gits rule · Post by **Ole gits rule** » Thu Nov 24, 2022 6:25 pm

An e89 6 cal is normally 23i /30i or 35i or 35iS

An e89 4 cal is normally 18i / 20i or 28i

e85 (older generation) and g29 (new generation) have sift tops, e89 is the only zed with a hard top

B21 · Post by **B21** » Thu Nov 24, 2022 7:13 pm

An e89 6 cal is normally 23i /30i or 35i or 35iS.. 23i and 30i are N52 powered ..35i/s is N54 powered

An e89 4 cal is normally 18i / 20i or 28i all N20 powered

e85 (older generation) and g29 (new generation) have sift tops, e89 is the only zed with a hard top

B21 · Post by **B21** » Thu Nov 24, 2022 7:14 pm

vinman wrote: ↑Thu Nov 24, 2022 5:06 pm Ok, you got me thinking now. So the e89 with N54 would be what you would recommend? And I could use some help in deciphering what engine is in the cars that I am looking at. Besides it being a z4, how can I narrow my search to get a stick, hard top and the 'correct' engine; until you mentioned e89 I had no idea what that was in reference to as well as the N20, N54...etc. How do I know what engine is in each car that I look at online? Is that designated in the model name or in the vin#? Thanks from this very green newbie!

N54 powered E89 is a 35i or 35is…

Very powerful, heavy, not as sweet handling and much more problematic than the N20 18i/20i/28i….

Silverstar · Post by **Silverstar** » Thu Nov 24, 2022 7:15 pm

N4LLY wrote: ↑Thu Nov 24, 2022 5:22 pm You can re-map a 18 and get 28 performance without issue's. Looking for a 20 may give you a much better spec'd car.
It worked for me

I might be wrong but I don't think the US got the 18i or 20i they usually don't get the smaller engines (or in this case lower output engines) over there.

For the OP:

Z4 Sdrive 28i = 2.0 4 cylinder turbo N20 engine
Z4 Sdrive 20i = 2.0 4 cylinder turbo N20 engine (not sure if this version was available in the US)
Z4 Sdrive 30i = 3.0 6 cylinder naturally aspirated N52 engine
Z4 Sdrive 35i or 35is = 6 cylinder twin turbo N54 engine

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