[JGG75]

Hello, I'm after some advice please. I'm looking to buy a 330i E90 convertible (2006-2010 era) in the next week or so but understand their are different editions of the engine e.g. N53, N52 etc.
I wanted to know which is the best edition of the engine in terms of sound, economy, performance etc. and which one should be avoided?
Also how can I tell when I go to view a car which edition of the engine it is?
Thanks in advance and appreciate any further advice...

[whyzee125]

Originally Posted by JGG75

Hello, I'm after some advice please. I'm looking to buy a 330i E90 convertible (2006-2010 era) in the next week or so but understand their are different editions of the engine e.g. N53, N52 etc.
I wanted to know which is the best edition of the engine in terms of sound, economy, performance etc. and which one should be avoided?
Also how can I tell when I go to view a car which edition of the engine it is?
Thanks in advance and appreciate any further advice...

They're both good engines, but I would prefer the N52, all else being equal. The n53 is more like an n54 without the turbos. More complication and more modern but less reliable. They have the n54's extremely expensive and problematic injectors and HPFP. They make a few more ponies but not a significant amount. The n52 sounds better to my ears.

N52: simpler, more reliable, sounds better

N53: slightly more power and improved mpg

[Markos ZimZimma]

Had the N53 in my 325i and it gave me no problems at all, but from what I can tell the N52 sounded simpler and more reliable, as above. The injectors are a concern on the N53, if they go then you're supposed to change all of them, and they're £200/£250 each plus fitting, and there's no cheaper parts to fit as I understood it. In my E91 it wasn't unusual for me to get 37/38mpg on a long run sticking to speed limits which was pretty impressive (although I've since got 42mpg on my N55 engined F31!).

[0l0dom0l0]

I've owned both, an N52 in a 130i, and currently have an E92 330i with the N53.

I was after a 330i with the N52 when searching for mine but ended up with the N53 as it was at a price I couldn't refuse.

I've certainly been impressed with it - very refined and smooth.

As above, HPFP, injectors and the NOX system are problematic. If I was buying one now, I'd want to see history of those parts being changed unless it was very cheap or really low mileage.

The injectors are now £350 each, NOX sensor is £300 and a HPFP is £800 so it can soon add up - which puts a lot of people off. You'll also need to be mechanically minded as that's just parts prices, not fitted.

[JGG75]

Thanks all for your guidance. One question...I'm going to see a 2007 330i tomorrow, how do I tell which engine version it is, is their a badge or label somewhere?
Thanks

[Dormermike]

Look for the valvetronic bulge on the engine cover. If it's there, n52. If not, n53.

[OliSharp]

Originally Posted by JGG75

Thanks all for your guidance. One question...I'm going to see a 2007 330i tomorrow, how do I tell which engine version it is, is their a badge or label somewhere?
Thanks

Yes, the label in the drivers door jamb has the engine code

[OliSharp]

Originally Posted by 0l0dom0l0

I've owned both, an N52 in a 130i, and currently have an E92 330i with the N53.

The injectors are now £350 each, NOX sensor is £300 and a HPFP is £800 so it can soon add up - which puts a lot of people off. You'll also need to be mechanically minded as that's just parts prices, not fitted.

Where are you finding injectors for £350? I’m only finding second hand ones on eBay at that level. They’re £420 from Cotswold with a discount.

[0l0dom0l0]

Originally Posted by OliSharp

Where are you finding injectors for £350? I’m only finding second hand ones on eBay at that level. They’re £420 from Cotswold with a discount.

Ebay item 265738008598.

Also available from ML parts for a bit more. They did have them available for £315 unil a week ago.

Cotswold hasn't been the cheapest place for a while in my experience.

[Markos ZimZimma]

Originally Posted by OliSharp

Where are you finding injectors for £350? I’m only finding second hand ones on eBay at that level. They’re £420 from Cotswold with a discount.

Each?? Are they bespoke one-offs FFS? At that price it's worth having a decent warranty that covers injectors on the car... absolute no brainer. Think they've quadrupled in price over the last 3-4 years.

[OliSharp]

Originally Posted by Markos ZimZimma

Each?? Are they bespoke one-offs FFS? At that price it's worth having a decent warranty that covers injectors on the car... absolute no brainer. Think they've quadrupled in price over the last 3-4 years.

They’ve certainly shot up in price. First one I bought was £150 and I thought that was a lot at the time!

[Sayek]

Originally Posted by JGG75

Thanks all for your guidance. One question...I'm going to see a 2007 330i tomorrow, how do I tell which engine version it is, is their a badge or label somewhere?
Thanks

TBH I would advise against buying a BMW that old unless you can tackle lot of the service and repairs DIY. Unless the previous owners have maintained without worry about cost then you will have tired suspension with shocks and most bushes tired by now therefore won't really enjoy the drive unless suspense refreshed.
And as already mentioned the fuel injectors.
If you have 6 leaking fuel injectors the parts alone will make the car beyond economical repair

[Sayek]

Originally Posted by OliSharp

They’ve certainly shot up in price. First one I bought was £150 and I thought that was a lot at the time!

I replaced 4 injectors while owned N43 between 2015 and 2020 and paid around £175 each. They certainly have increased a bit

[Dormermike]

Got rid of my n53 because of the injector costs, must admit. 7 years and faultless but just meant that each passing mile was getting riskier. I noticed the odd stumble at cold start so off it went.

[micdev42]

- and they are now £440 from Cotswold. Replace all 6? £2700? That will do nicely sir...

[Markos ZimZimma]

Originally Posted by micdev42

- and they are now £440 from Cotswold. Replace all 6? £2700? That will do nicely sir...

At that sort of money I just wouldn't buy an N53-engined car anymore if I was looking for one. That's a big bill on any car never mind one that might be worth around the same as those 6 injectors. Would love to know how they've gotten so expensive...