thinking about upgrading to a 35i. Advice please?

clarker63 · Post by **clarker63** » Mon Sep 24, 2018 10:50 am

Hi Guys, I've currently got a low mileage E89 09 23i, and really like it, but I've been toying with the idea of upgrading to a 35i/is (for obvious reasons!)

I posted previously that I didn't think I could afford the upgrade path, but recently I've found a couple 09 35i/DCT that I could stretch to but I am naturally cautious of moving from my car which I am really happy with. Hence your thoughts on the following might help me make up my mind.

I believe the differences between the 35i/DCT and 35is/DCT is 30 more horses, different bumpers, and M sport badges. Are there any other differences Ive missed? (yes I'd love a low mileage 35is/DCT but the cost will be much more).

These have done about 80k miles. How expensive is a DCT clutch change and when are they likely to be required?

The engine appears to have a few foibles, reading previous posts. Anything I should really be checking for that is expensive and wouldn't be covered under AUC warranty? The AUC warranty is £100pm. I've got it for the 23i (about £50 pm, really in case something expensive goes wrong).

I was shocked by the WBAC valuation on one I was looking at - £6900 whereas the actual prices are about twice that. My 1 owner 23i is valuation is more than that....

obviously I'd love the additional performance, but I'm not sure yet that I've convinced myself that its not going to be costing me an absolute fortune to run!

Cheers guys!

clarker63 · Post by **clarker63** » Mon Sep 24, 2018 11:11 am

I notice these on the comprehensive fault list.

High pressure fuel pump
Ignition coils
Adjustable dampers
Turbos

Couldn't see anything about the DCT clutch replacement!

Hunter · Post by **Hunter** » Mon Sep 24, 2018 12:07 pm

I have a 2012 35iS and it’s a much better car than the 3.0 sdrive I had a while ago. I drive a mixture of town and motorways and average 29.8 mpg, this isn’t bad for the performance on offer.

IRD · Post by **IRD** » Mon Sep 24, 2018 12:25 pm

I have recently bought a 3.5 is from another Forum member with 37000 miles on the clock. It is covered by a BMW backed AVIVA warranty. With such a complex piece of machinery it is essential to have cover. Fortunately it is a weekend car so I am not totally reliant on it for daily transport. I don’t think I would have bought it if it had been my main form of transport where I would have been piling up the miles. Yes the performance is brilliant and the sound of the exhaust brings a smile to my face every time I drive the car but if running costs are a concern I would think carefully. I average about 30 mpg but, as you might expect, that drops significantly. If you use the performance available and it’s very hard not to do so. I used to own a a 2.3 s way back in 2010 and loved that too. So,in short, the 3.5 is brilliant to drive and I make excuses to drive it but it will almost certainly cost you significantly more to run than your current car. However, If you feel you can afford the running costs you won’t be disappointed.

clarker63 · Post by **clarker63** » Mon Sep 24, 2018 1:01 pm

Cheers guys, running costs are not an issue - my 23i isn't much better on fuel.... and I too have another car for day to day trips, so it would be a weekend/fun car.

Its more about what it costs when it goes wrong, and the risks of having to pay to fix a 10 year old performance car is what I am questioning.

Hunter · Post by **Hunter** » Mon Sep 24, 2018 1:19 pm

clarker63 wrote: ↑Mon Sep 24, 2018 1:01 pm Cheers guys, running costs are not an issue - my 23i isn't much better on fuel.... and I too have another car for day to day trips, so it would be a weekend/fun car.

Its more about what it costs when it goes wrong, and the risks of having to pay to fix a 10 year old performance car is what I am questioning.

its a BMW with normal BMW reliability qualities. no better or worse than the other cars in the range. Its not a highly tuned machine on its limits of performance and operates well within its tolerances..in fact the engine will be less stressed than smaller engines cars because the engine doesn't have to work as hard to achieve the performance of other cars in the range.
Cost wise i should imagine that a BMW part will be the same across the range, the accessibility and therefore labour charges will be the same as other 6 pots.
Its not a time bomb waiting to go bang (unlike porkers with borescore and ims issues) so go get one and enjoy it.

HillWalker · Post by **HillWalker** » Mon Sep 24, 2018 2:07 pm

HPFP issues were very common on the early cars 2009/2011, if I were you I'd wait a while save some more cash and get a more recent model. Having said that when you do come to change a 35i/35is is definitely the way to go especially for the enjoyment you are looking for in a weekend toy.

Beeacon · Post by **Beeacon** » Mon Sep 24, 2018 3:31 pm

A cheaper way of upgrading the power would be to get a tune on your current model. As the engines are the same for the 20i/23i/28i (just a different tune), you could boost your current car up to ~270hp which may fill in the gap that you're looking for.

Just something to consider.

Pbondar · Post by **Pbondar** » Mon Sep 24, 2018 3:35 pm

Beeacon wrote: ↑Mon Sep 24, 2018 3:31 pm A cheaper way of upgrading the power would be to get a tune on your current model. As the engines are the same for the 20i/23i/28i (just a different tune), you could boost your current car up to ~270hp which may fill in the gap that you're looking for.

Just something to consider.

The 23i is not the same engine as the 18i 20i 28i. It’s not very tuneable at all.....in comparison to the big wins with the other that are all N20B20 engines ...

Beeacon · Post by **Beeacon** » Mon Sep 24, 2018 3:38 pm

Pbondar wrote: ↑Mon Sep 24, 2018 3:35 pm
Beeacon wrote: ↑Mon Sep 24, 2018 3:31 pm A cheaper way of upgrading the power would be to get a tune on your current model. As the engines are the same for the 20i/23i/28i (just a different tune), you could boost your current car up to ~270hp which may fill in the gap that you're looking for.

Just something to consider.
The 23i is not the same engine as the 18i 20i 28i. It’s not very tuneable at all.....in comparison to the big wins with the other that are all N20B20 engines ...

My bad, clearly I'm getting confused between engines.

clarker63 · Post by **clarker63** » Mon Sep 24, 2018 3:51 pm

Pbondar wrote: ↑Mon Sep 24, 2018 3:35 pm The 23i is not the same engine as the 18i 20i 28i. It’s not very tuneable at all.....in comparison to the big wins with the other that are all N20B20 engines ...

agreed.

I noted Pbondars response to buying a 35i/is in the "problems" section.. I'm feeling similarly challenged! I'd like to buy it for a month, then decide.. I could do that I suppose! lol

R.E92 · Post by **R.E92** » Mon Sep 24, 2018 5:04 pm

With the 35is there are no physical changed to the engine, the reason for the extra 30 horses is a higher boost pressure setting in the ECU. You can buy the 35i and then use MHD Flasher app on your phone to boost it to 35is levels or even further if you with for around £100 including the cable necessary.

Reliability is a problem with the N54 engine and as far as I'm aware the newer models aren't much better until the 2014 model. From 2014 onwards they revised the injectors to the current "version 12" which appear to be reliable.

Just buy the nicest example you can afford and get yourself the extended BMW warranty.

Pbondar · Post by **Pbondar** » Mon Sep 24, 2018 5:07 pm

clarker63 wrote: ↑Mon Sep 24, 2018 3:51 pm
Pbondar wrote: ↑Mon Sep 24, 2018 3:35 pm The 23i is not the same engine as the 18i 20i 28i. It’s not very tuneable at all.....in comparison to the big wins with the other that are all N20B20 engines ...
agreed.

I noted Pbondars response to buying a 35i/is in the "problems" section.. I'm feeling similarly challenged! I'd like to buy it for a month, then decide.. I could do that I suppose! lol

I think there will be an eternal battle between the 6 potters and the 4 potters...

The issue is that the 6 potters especially the 35 series are getting older and there are big ticket items that can wrong that are specific to those models, high pressure fuel pumps, turbos, wastgates, adaptive suspension, injectors and coils to name most?

The 4 potters benefit from the later generation of design in part learnt from the issues with the 6 potters.

Sometimes new designs are mere evolutions of an earlier..the successor to the N20 found in the new Z4 is one..on the other hand the new 6 potter in the Z4 40 version is a major re-design and address precisely some of the issues that the E89 35 had.

Ignoring the dynamic issues of the 6 potters that some people say when compared to the 4 potters it then boils down to, as I think someone else said..

Do you feel lucky..punk?

And do you care if it costs a small fortune as a percentage of the car to fix it...

If the answer is either yes to the first or no to the second do what your heart says..after all it is but a toy...

This will rumble on...eventually all the 6 potters will have had the expensive bits replaced and they then will be in a better and cheaper place...

Because the N20 engine was used/still used widely second hand ones are in plentiful supply at reasonable prices and anecdotally they do not seem to be blowing up/breaking down that often given how many were made..

Being a sad bunny I was, when I was paranoid about the n20 longevity even thought of buying a spare engine as they can be had for less than most if the 35 engine parts...

I think until you’ve tried a 28i or a re-chipped 20i then I’m not sure you can judge..

You could always buy with the large amount if money you would save a Ducati sound..CD...with the change..

All this of course MHO...others will disagree...

IRD · Post by **IRD** » Mon Sep 24, 2018 6:35 pm

clarker63 wrote: ↑Mon Sep 24, 2018 1:01 pm Cheers guys, running costs are not an issue - my 23i isn't much better on fuel.... and I too have another car for day to day trips, so it would be a weekend/fun car.

Its more about what it costs when it goes wrong, and the risks of having to pay to fix a 10 year old performance car is what I am questioning.

In the light of what you are writing about costs. Just look for a really well cared for car that has had some of the more expensive items (eg shocks) replaced. Take out a good warranty and go for it. These cars really are a delight to drive and I guarantee you will be looking for excuses to drive it. Maybe find one in a garage and try it for yourself. Then you will see whether you definitely want to buy.

Rathean · Post by **Rathean** » Mon Sep 24, 2018 8:34 pm

Just do it!!

I upgraded from a 23i to a 35i and the 35i engine was a revelation, effortless acceleration, some serious poke when needed but most of all its a super accomplished refined commuter mule that just looks better than most other cars on the road

Economy I can get 31-32 mpg driving like a nuns mum on the motorway, nearly 400 to a tank but throw in some shorter trips to the shops etc and that'll be closer to 350 from a tank.

I'd steer clear of M Sport suspension, the standard set up is half as harsh but stiffens up nicely in Sport mode if the mood takes you. I found the M Sport just too harsh if you're using it as a daily on any road with minor defects... so that's pretty much every road

Just keep an eye on the speedometer... "motorway speeds" creep up on you without realising in the 35i

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