630i to Z4 3.0si

[carbon83]

Hi all

What are members opinions on the E86 Z4 3.0si? I currently have a E63 630i (2009) but am thinking of making the step to the Z4 (2008)?

My 6 series is proving a little problematic and the Z4 I have seen is very clean and looks stunning but interested in members thoughts.

Thanks.

[g3org3y]

carbon83 said:

Hi all

What are members opinions on the E86 Z4 3.0si? I currently have a E63 630i (2009) but am thinking of making the step to the Z4 (2008)?

My 6 series is proving a little problematic and the Z4 I have seen is very clean and looks stunning but interested in members thoughts.

Thanks.

I suppose it depend on what you're after as they are very different cars.

I'd expect the 6 is quite a nice, smooth relaxing drive. The Z4 is quite lively to drive, especially on run flats as it has a tendency to tramline. Lots of Z4 owners change to non run flats and then chuck an E46 space saver in the boot. It has the EPAS which is (imo) not as good as the hydraulic steering on the E90.

It certainly shifts with the 3.0 litre engine. Whereas on the 6, an auto would suit, I think the Z4 needs a manual.

What's the spec like on the Z you've seen?

Calling Mr Tidy He's your man for Z4 Coupe knowledge.

[Mr Tidy]

Oh well, here I am!

I've had 2 Z4 Coupes over the last 5 years - so it's probably fair to say I really like them.

Depending on the age of you 630i it may have the same N52 engine, so the potential mechanical issues like dead electric water pumps and leaking cam-covers will be the same.

But they seem to be pretty robust engines that cope well with high mileages - I had an E91 325i with the 2.5 litre version of the N52 that had done 139K when I sold it in April and it still ran really well.

One issue I had with my current E86 was corroded rear brake pipes. They go under the floor below the passenger seat inside a plastic cover, but the cover stops in front of the rear axle. The end of the cover gets full of road debris which holds moisture so the pipes corrode, and to fit new OEM ones you need to drop the fuel tank to get the driver's side one into the retaining clips. I had mine replaced with copper so it could be threaded through the clips then flared afterwards - much easier and cheaper! So it's worth checking them out if you can.

And when the tailgate is open check all round it - some have suffered from rust and BMW only gave a 12 year warranty so that has expired for quite a few of them.

I've always liked the 6 Series, but have never had one - although I do have an E90 330i as a daily with the same engine, and even compared to that the E86 feels noticeably quicker. Plus you can hear the engine much more, which I think suits a 2 seater as does a manual gearbox IMO.

And I'd agree totally with g3org3y about the EPAS on the E86 not being great - the HPAS on my E90 provides much more feel.

While E86s do seem prone to tramlining, it seems having all suspension bushes in good condition, decent brands of tyres with good tread and the right pressures (and reportedly using non-run-flats, although I haven't tried that yet) all help to avoid that problem. Mine had new front control arm bushes last month and drives much better for them!

Bear in mind all E86s came with a pretty basic spec (unlike a 6 Series I expect) so if you must have rear parking sensors, Bi-Xenon headlights, cruise control, heated seats, cup-holders, power-fold mirrors or Sat-Nav as they were all options you need to look out for them. But all the Coupes had electric seats with driver's memory. And cruise is a fairly simple retro-fit once you've bought the control stalk and a section of wiring loom that can be bought pretty cheap from one of the guys on z4forum - which is well worth a visit before you buy.

Anyway good luck if you do decide to go for one.

Edited by Mr Tidy on Wednesday 7th August 23:43

[naturalaspiration]

Your E63 is a facelift one with a direct injection N53 engine with a fair share of problems - leaky injectors, NOx sensors, high pressure fuel pump to name the usual suspects. All fixable, but if the injectors aren't replaced promptly, the leak may cause a cylinder bore wash leading to high oil usage and , even more worringly, a loss of compression. Once sorted it's a very good engine.

The E86 has the last of it's kind inline 6 N52 engine, with port injection which avoids the above issues. The issue however with E85/6 is linked to sticky steering column, only in hot weather - apparently fixable as per instructions on the Zed forum - note if the MM/YY is 07/07 onwards this should not occur as BMW has since then been fitting a revised part. The two cars are very far apart in what they are trying to achieve - 6 is a true GT, for long effortless drives, whereas Z4 coupe is a true to its roadster credentials - long bonnet, intimate (cramped) cabin, seats low and far aback, practically above the rear axle, direct, harsh, and with a beautifully audible engine note in the cabin (on purpose - there is a resonator piping connecting the intake manifold and the cabin - dampened of course) - turning every drive into an event. Character-wise the 6, being a GT, is better matched to an auto, whereas an auto in the E86 I would consider a blasphemy! :-)

For me these cars are automotive icons, each in it's own right - E63 a road going version of the inimitable Z9 concept, and E85/6 BMWs take on the modern roadster, outrageously brilliant. Ever since Bangle left, BMW has been trying to find its new design direction. Not impressed so far I must say.

Edited by naturalaspiration on Thursday 8th August 00:29

[carbon83]

Thanks all!

Yeah my E63 is a N53 and in the last year I've had all 6 injectors replaced, nox sensor replaced, some sort of port, rear fog light replaced, sump oil gasket (all fixed by bmw under warranty other than oil gasket) and now some sort of fluid leak which is booked in with bmw next week.

So that's why I'm thinking of getting rid and going for a z4 with a n52..

Not sure if I should just get the E63 fixed though but it seems to be one thing after another.

Thanks

[g3org3y]

naturalaspiration said:

The E86 has the last of it's kind inline 6 N52 engine, with port injection which avoids the above issues. The issue however with E85/6 is linked to sticky steering column, only in hot weather - apparently fixable as per instructions on the Zed forum - note if the MM/YY is 07/07 onwards this should not occur as BMW has since then been fitting a revised part. The two cars are very far apart in what they are trying to achieve - 6 is a true GT, for long effortless drives, whereas Z4 coupe is a true to its roadster credentials - long bonnet, intimate (cramped) cabin, seats low and far aback, practically above the rear axle, direct, harsh, and with a beautifully audible engine note in the cabin (on purpose - there is a resonator piping connecting the intake manifold and the cabin - dampened of course) - turning every drive into an event. Character-wise the 6, being a GT, is better matched to an auto, whereas an auto in the E86 I would consider a blasphemy! :-)

OP, I suppose it depends whether the character of the Z4 is what you're after (compared to the 6er).

carbon83 said:

Thanks all!

Yeah my E63 is a N53 and in the last year I've had all 6 injectors replaced, nox sensor replaced, some sort of port, rear fog light replaced, sump oil gasket (all fixed by bmw under warranty other than oil gasket) and now some sort of fluid leak which is booked in with bmw next week.

So that's why I'm thinking of getting rid and going for a z4 with a n52..

Not sure if I should just get the E63 fixed though but it seems to be one thing after another.

Thanks

Definitely understand your frustrations.

N52 isn't totally problem free, also likes to leak (sump pan, oil filter housing and cam cover).

As an aside, minor grumble: I dislike the sound of the indicators on the Z4. A lot crappier sounding than my older E36 or the current E91.

[Mr Tidy]

carbon83 said:

Thanks all!

Yeah my E63 is a N53 and in the last year I've had all 6 injectors replaced, nox sensor replaced, some sort of port, rear fog light replaced, sump oil gasket (all fixed by bmw under warranty other than oil gasket) and now some sort of fluid leak which is booked in with bmw next week.

So that's why I'm thinking of getting rid and going for a z4 with a n52..

Not sure if I should just get the E63 fixed though but it seems to be one thing after another.

Thanks

To be fair that is why I limited my 3 Series search to cars with N52 engines - I didn't need the grief of HPFP or injector failures, or coked up inlet manifolds.

[naturalaspiration]

I understand that, apart from the direction injection part, N53 and N52 are very similar engines and therefore should share similar issues.

[bmwmike]

Similar to a degree. Mostly just block construction, cylinder lining and internals. Heads are very different as N53 doesn't have valvetronic. N53 also has replaceable cam carriers. Cam chains are different I think, n53 shares same as n43 but doesn't seem to give issues.

I've got an n53 and would have another. Performance and economy is remarkable all things considered.

[Z4MCSL]

Ive got an E86 3.0si as well as M Coupe and love both cars.

I wasn't expecting to but I actually ended up preferring the 3.0si as a daily driver - due to a mixture of a more driveable gearbox and the suspension being less firm.


I am actually also looking into supercharging it as it looks to achieve better power than the M but will still be a more comfortable drive.