E85 M54 or N52?

E85 M54 or N52?

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300bhp/ton

Original Poster:

41,030 posts

191 months

Friday 16th August 2019
quotequote all
If looking at 3.0i only cars.

Is there any advantage to the earlier M54 powered ones or the latter N52 ones?


I guess this question is 2 pronged:

  • Is one engine nicer or more reliable than other? According to Wikipedia the earlier M54 makes slightly more power at 228hp vs 215hp for the latter N52. Probably not enough difference to worry about. Although there does seem to be a 35ft-lb torque difference, in favour of the older engine. Has anyone driven both engines in a Z4? On paper it looks like the older M54 could be more enjoyable.
  • Were there any major updates with the N52 facelift other than the engines? I think the lights changed a bit. But anything else a bit more tangible rather than visual? As in, apart from the engine, what other reason would you want or prefer a facelift model?

BTW - I know there is the 3.0si with 261hp, but lets just ignore it for now.

cerb4.5lee

30,699 posts

181 months

Friday 16th August 2019
quotequote all
I had the N52 in a 330i and I personally prefer the noise that the M54 makes. The M54 is a little bit more vocal and it has more of the traditional straight six noise to it for me.

cerb4.5lee

30,699 posts

181 months

Friday 16th August 2019
quotequote all
The N52 is a very solid engine though and nothing went wrong with mine over the 4 years I had it. I even escaped the water pump failing which is a common thing with them.

naturalaspiration

639 posts

84 months

Friday 16th August 2019
quotequote all
Facelift 2.5si makes 218 bhp and tend to be cheaper than 3.0i/si. Sound wise M54 sounds more like old school BMW; N52 is a bit clinical to me. Only 3 litre units have the intake resonator for the added drama in the cabin (but not the weaker N52 3L I think) - easily retrofitted to any other 6 cylinder engine.

bodhi

10,525 posts

230 months

Friday 16th August 2019
quotequote all
The N52 with 218bhp will be badged as the 2.5i - the 3.0i should have around 260 bhp depending on which N52 they put int he Z4, with the 3.0si having 272 bhp.

Personally I far prefer the N52 - more power, better on fuel, less likely to drink oil. Much prefer the soundtrack with it - in the 1 Series anyway, assuming the Z4 is similar - still a "creamy grenade" as evo called it, but with a fantastic bark as it goes through the midrange. In fact it's probably one of my favourite automotive sounds around 3500 rpm in 2nd. Sounds even better in a tunnel smile

300bhp/ton

Original Poster:

41,030 posts

191 months

Friday 16th August 2019
quotequote all
Thanks.

Seems the model lineup is a little confusing (like all BMW's... ffs rolleyes )


Looking at the info on Wiki it has a table showing a 3.0i and a 2.5is for the same years. With identical power and torque. But different displacement and performance.

Is this actually correct or is Wiki wrong?

https://en.wikipedia.org/wiki/BMW_Z4_(E85)




Anyone able to clarify the UK line up over the years? I'm not interested in the M models, nor the entry base models. But something with over 200hp, be it a 3.0 litre or a 2.5 litre.

Court_S

12,980 posts

178 months

Friday 16th August 2019
quotequote all
bodhi said:
The N52 with 218bhp will be badged as the 2.5i - the 3.0i should have around 260 bhp depending on which N52 they put int he Z4, with the 3.0si having 272 bhp.

Personally I far prefer the N52 - more power, better on fuel, less likely to drink oil. Much prefer the soundtrack with it - in the 1 Series anyway, assuming the Z4 is similar - still a "creamy grenade" as evo called it, but with a fantastic bark as it goes through the midrange. In fact it's probably one of my favourite automotive sounds around 3500 rpm in 2nd. Sounds even better in a tunnel smile
I'd agree with this - does the Z4 carrying over the M54 engine suffer the same issues with the chocolate cooling system that the E46's did?

I had a 330 with the N52 for three years and other than an issue with the VANOS actuators it was perfect from 64k to 95k. Used bugger all oil (unlike my E46 325). I also escaped the water pump failure in my N52.

Regarding noise, my 330 sounded lovely when I fitted the M Performance carbon air intake, with a lovely rasp in the last 1,000rpm.

naturalaspiration

639 posts

84 months

Friday 16th August 2019
quotequote all
Z4 for European market never got the detuned 3 litre N52. It did however have two N52B25 units: a detuned 2.5i with 177 bhp and the "proper" 2.5si with 218 bhp.


300bhp/ton

Original Poster:

41,030 posts

191 months

Friday 16th August 2019
quotequote all
Thanks for the info. Guess a 2.5is would suit just as well.

And from what I’m hearing is potentially a slightly more reliable option than the M54. But maybe doesn’t sound as good. But both engines seem to have some degree of reliability issues.

Do E85 Z4’s suffer rust issues like other period BMW’s?

Court_S

12,980 posts

178 months

Friday 16th August 2019
quotequote all
300bhp/ton said:
Thanks for the info. Guess a 2.5is would suit just as well.

And from what I’m hearing is potentially a slightly more reliable option than the M54. But maybe doesn’t sound as good. But both engines seem to have some degree of reliability issues.

Do E85 Z4’s suffer rust issues like other period BMW’s?
I don’t think so. It’s not unheard of but it’s not like an E46 which is almost guaranteed.

Mr Tidy

22,394 posts

128 months

Friday 16th August 2019
quotequote all
I haven't heard of an rust issues with E85s (although some E86s can have it on the underside of the tailgate).

But the rear brake pipes can suffer from corrosion - usually at the end of the cover under the passenger seat.

I believe the M54 E85s suffer the same cooling system issues as in the E46s.

I've had 4 N52 engines, 2 in E86s, one 325i E91 and an E90 330i. Two electric water pumps have died (so far). rolleyes

The problem is they don't wear like a mechanical pump, they just stop working so it's a recovery job when they do! If one goes just don't buy from BMW - they charge over £500 but you can find the same Pierburg pump for half that.

I really like the N52 engine - after all we won't see N/A straight 6s with a 7,000 rpm red-line again! And they sound so much better in a Z4 than in a 3 Series, but I suppose that is to cater for the different buyers they were aimed at. I don't know why, but my E90 is rated at 258 PS and my E86 at 265 PS. confused

Other than that they seem pretty solid - my E91 had 139K on it when I sold it and was still running sweetly.

The other potential upside with the N52 is it came with the facelift in 2006, so there are some cosmetic changes. And from then onwards there were 2 trim levels, SE and Sport. Sport models get M-Sport seats as standard that were otherwise an option - and even used pairs can sell for the best part of £1,000! Plus they have M-Sport suspension that is 15mm lower, and stiffer.

Probably well worth a root around on z4forum. thumbup


g3org3y

20,638 posts

192 months

Friday 16th August 2019
quotequote all
N52 imo, more powerful and more torque and according to the BMW literature 10kg lighter. Negatives: electric waterpump is more expensive.

An interesting overview of the N52 in this BMW Document: https://bmwpartsmontreal.files.wordpress.com/2016/...

I've got an N52 engined Z4 (3.0Si) and N52 engines E91 (330i). Interestingly, the character feels different as the Z4 is a manual and the 3 Series has an autobox. Both seem to be a bit leaky (needing valve cover gaskets). Other areas are the sump pan gasket and oil filter housing gasket. Some N52s have issues with ticky hydraulic lifters.

IMO Z4s shouldn't have any rust unless they've had (bad) accident repairs.

https://z4-forum.com/forum/ is a great source of info.

In fact, here's a thread discussing your very question: https://z4-forum.com/forum/viewtopic.php?t=21468


Edited by g3org3y on Friday 16th August 20:55