Which Z4 should I buy?

[Mono46]

Afternoon All

Another Newbie here looking to get into Z4's. I've been looking for a while, done some man maths and decided i can now afford to (just)! I really want a 6 cylinder, E85 3.0 Si but my searches have also started heading to mighty M's. Values seem all over the place at the moment.

I've been to look at an M today that's on eBay, for £14,950, with 86k on the clock, the mechanicals look at (it has service history)and drives really well but has some paint around the arches, under the indicator/badges on the side which has been blended in but still visible. Is this sensible money for something that would become a rolling project (I'd look to repaint) or should i pay more now for lower milage/better paint?

Or should i stick with the 3.0Si like i originally intended?

Some advise from folk who have see it, done it and got the T shirt would be appreciated!

Cheers

[enuff_zed]

Welcome aboard.
Straight in at the deep end then?
I confess I've owned neither, but picked up a fair bit of info over the years on the forum.
My thought is that if you can only (just)! afford one then you probably won't afford to do an 'M' justice at this point.
Don't buy the top dog car then ruin it due to lack of maintenance. Buy the next best thing which should be a lot cheaper to run.

[Ole gits rule]

Welcome aboard.
Straight in at the deep end then?
I confess I've owned neither, but picked up a fair bit of info over the years on the forum.
My thought is that if you can only (just)! afford one then you probably won't afford to do an 'M' justice at this point.
Don't buy the top dog car then ruin it due to lack of maintenance. Buy the next best thing which should be a lot cheaper to run.

Well said, if you buy the car for £15k, how much is a decent paint job - better off finding a better car to start with IMHO

[tiglon]

You're probably better off buying a 3.0si in very good condition than a ///M in poor condition, if you want to be pragmatic. The 3.0si will still be more than enough to put a smile on your face.

[AndyT]

The M is great but as snuff_Zed mentioned the costs of maintaining the M can be a lot more than a 3.0, I picked up a lowish mileage 46k full BMW service history and still looking at nearly £3k of work and only had it a few weeks (inspection II, new discs pads all round and a few other jobs that I wanted doing) and I’ve not even started on the mods (exhaust, air box, suspension, wheels etc)

Don’t forget the higher road tax and lower mpg if you’re running close to your budget, it all adds up.

Don’t get me wrong, I went into ownership with my eyes open and only wanted an M as hoping it to keep for 10+ years and do 80,000 miles in that time (hence wanting a low mileage)

I’d definitely consider the 3.0si as you should be able to get a good example with your budget if you’re looking for a roadster. I keep contemplating a 3.0si coupe as a daily

[Mono46]

Thank you so much everyone for your wise words, as I use to say to my ex 'I do hate it when you make sense'!!

Its going to be summer toy, so roadster for me, you are right in terms of buying the best you can afford, so that will be the 3.0 Si......if anyone knows of anyone with one for sale, point them in my direction!

Many thanks and look forward to posting a pic when I get one

[Mono46]

Thank you so much everyone for your wise words, as I use to say to my ex 'I do hate it when you make sense'!!

Its going to be summer toy, so roadster for me, you are right in terms of buying the best you can afford, so that will be the 3.0 Si......if anyone knows of anyone with one for sale, point them in my direction!

Many thanks and look forward to posting a pic when I get one

[Mr Tidy]

Hi and welcome to the forum.

I think your mind has been made up already, but I'd agree with what others have said. Running costs for an M are in a different league to a 3.0Si so you need to have a bit in your budget to cover that!

The 3.0Si has a great engine - I don't think you'd be disappointed with one.

Happy hunting.

[Mono46]

Hi and welcome to the forum.

I think your mind has been made up already, but I'd agree with what others have said. Running costs for an M are in a different league to a 3.0Si so you need to have a bit in your budget to cover that!

The 3.0Si has a great engine - I don't think you'd be disappointed with one.

Happy hunting.

[kaiser01]

Hi, I had a 2005 3.0 (07-14) and now have an M roadster (since Dec). The 3.0 was a good car and was pretty quick. I’d expect the Si (w/30bhp more) would be a really nice car. However, as an occasional car, the M is a far more special thing. The steering on non-M Z4s is pretty awful and run-flats make the ride worse than the M version. You can change the tyres, but you can’t really do much about the steering. The S54 engine is a fantastic thing and combined with the hydraulic steering and non-runflat tyres turns good to great.

The downsides (as previously mentioned) are the higher running costs. The valve adjustment is the major cost for scheduled maintenance and you’ll probably lose the car for a couple of days (the engine needs to be cold to do the job). Probably a £700-800 service with spark plugs (these are £18 each!).

Then you have what is technically preventative maintenance, but should called be inspection III, changing the big end bearing, which is every 60-80k. This is typically a £1k job.

Brakes are also very expensive compared to non-M Z4s. Front discs and pads are £500+, rears are £400+ for the parts, so over £1k to change them all. There isn’t a cheaper OEM spec option either. Non-Ms have loads of quality aftermarket options, even the BMW are quite good value, especially on 4+ menu pricing.

You should also treat the S54 with a lot of mechanical sympathy. It is a fairly exotic engine, so should be fully warmed up (oil temp is critical) before any significant load is put on it. With 10W/60 oil (and an iron block) this can take quite a while in the cooler months. Great if you are going out for a fun drive, but not so great for commuting in busy traffic.

The M54 and N52 are normal engines designed for use in BMWs saloon and SUVs. These are all aluminium or magnesium alloy, with light weight oil and lower redline. The heat up quick and don’t need the kid gloves that the S54 needs.

If you have the budget, the Z4 M is the best choice. For a roadster, £12-16K + £2K reserve fund is a good budget.

You’d be looking at £6-7K for an earlier 3.0 and £8-10K for the later 3.0 Si. You’ll probably need £1k in reserve.

The steering can be problematic on the non-Ms and can be as simple as lubrication(cheap / free), but could be a new / replacement column. This can be thousands.

Mine was £14.3k, 60K with FSH from a dealer. It was a trade-in at a main dealer that couldn’t go on approved used scheme due to age / mileage.

I’ve spent about £1.5k on it so far, new rear springs, tyres, M-badges (£100 for the trio), oil and filters, two throttle position sensors and a cooling fan. I’m going to get the bearings replaced later in the year and it will need an inspection 2 next year.

I saved a bit on the first failed throttle sensor and cooling fan. The sensor is cheap, but you have to remove the intake plenum which takes a few hours. The fan is expensive, but takes about 30 mins. I did the sensor myself so saved the labour, probably £200-300 and for the fan, rather than buying BMWs £700 part, I did a bit of research and found that one from a six cylinder E60 would work. Thankfully Mahle offers an aftermarket one for £250. All I had to do was remove the fan module from the E60 shroud and bolt it into my existing one.

So, you can help keep the costs down if you are prepared to do a bit of the work yourself.

Finally, I believe the Ms (and Alpinas) will be a better long term investment. The money you put in will be less than the longer term appreciation. If you look at other Ms and their non-M counterparts, you’ll notice the Ms bottom out, then appreciate gently for 5-10 years, then jump massively. It’s only once the big jump occurs so the non-Ms start to appreciate, as the Ms become out of reach. It’s not even a rarity thing either, I bet there are more E28 M5s than there are E28 525e still with us, but an E28 M5 would be 5-10x the price

[Mono46]

Thanks Kaiser01, clearly I have a lot to learn about these cars, a really great insight, it sounds like you got a really good deal on your M. I’m going to continue to look and then as the other guys have said, buy the best I can afford as a starter for ten.
All the best

[Mr Tidy]

Some excellent advice from "kaiser01".

Which pretty much mirrors my "M" experience. Bought it privately in December 2019 when it was advertised for £14K on 76K miles and due an Inspection II.

That cost £1K by the time a few extra items were factored in like a new cam-chain tensioner as the original was sticking and leaking. New bearing shells and engine mounts consumed another £1K. Both jobs done by trusted Indy Ross (bowser134 on here) but would have been considerably more at a main stealer!

Luckily brakes were all fine and supension had been replaced less than a year before I bought it, but that's before I got into modifications like going back from 19" CSL Reps to 18" OEM 224s with a refurb and new tyres, then £950 for a pair of aero sill covers.

My 3.0Sis were great cars, but the M just feels so much more special as soon as you start the engine. You just need to understand what you are getting into, but thankfully I went into it with my eyes open.

And you do have to treat the S54 engine with kid gloves until it has got properly up to temperature for the sake of the bearing shells if nothing else, but after that getting the revs up is such a wonderful experience!

Even if Ms do appreciate, taking into account the running costs I can't see any actual profit in it - but that isn't why I bought it!

I don't know much about Alpinas and nothing about their running costs, but in terms of what you get for what you pay a 3.0Si looks like the best of the rest to me.

[Mono46]

Thank you Mr Tidy, my search goes on (as does my indecision!)

[Mr Tidy]

To be fair before you decide the best thing you could do would be to experience all of your options and go from there.

Going back to your first post I wouldn't worry too much about mileage, it's all about condition and history. Personally I'd be wary about one needing paint - for a decent job that can get expensive very quickly!

And for an 86K mile M I'd budget at least £1K for new bearing shells and engine mounts if they hadn't been done, plus another £1K for an Inspection 1 or 2 if it was due either of those. Then add some to the maintenance pot if it was on original suspension and a bit more if it was needing brakes!

Budget creep - or Man Maths - in action.

Just for info my bearing shells looked like this when I got them replaced at 78K miles.

Bearing Shells 260820.jpeg (403.48 KiB) Viewed 359 times

Having copper showing means they are on their way out!

If you are ever near GU47 you'd be welcome to have a poke around my MC and a ride in it.

[Mono46]

Thank you for the kind offer Mr Tidy, appreciated. I’m just going to take my time and have a look at a good number of cars to make sure, as best I can, I buy a decent example.

Looks like you got to the bearing shells just in time!