E91 Straight Six Bearding

[Gunk]

RelentlessForwardProgress said:

Alpina tune on the ZF6 is great, if anything, I wish it would hold 6th and not kickdown to 5th (say you’re at 80 and just want to hammer along faster). If I knock it into sport it will still do it. I’m sure my B3 3.3 with the 5 speed ZF would hold the gear.

Anyway, it’s responsive and very slick, though has just had a full gearbox service.

I’ve yet to try the ZF8 and surprised to hear it’s anything other than the holy grail of boxes!

The ZF8 with the 330d or 335d is a superb gearbox, absolutely seamless. Much better then my wife’s 6 speed Golf DSG

[Court_S]

RelentlessForwardProgress said:

Alpina tune on the ZF6 is great, if anything, I wish it would hold 6th and not kickdown to 5th (say you’re at 80 and just want to hammer along faster). If I knock it into sport it will still do it. I’m sure my B3 3.3 with the 5 speed ZF would hold the gear.

Anyway, it’s responsive and very slick, though has just had a full gearbox service.

I’ve yet to try the ZF8 and surprised to hear it’s anything other than the holy grail of boxes!

I’m hoping that a trip to P Torque in the new year will speed the gearbox up. My friend says his his much better after the same treatment. My warranty expires in April and if I decide not to renew, I’ll get the gearbox mapped. Will look into the 1M throttle map too which is a bit sharper.

[bmwmike]

Court_S said:

Swervin_Mervin said:

I don't like the ZF8. And I prefer the ZF6.

I might be mental, but that's based on having lived with both. The ZF8 I found too fussy - especially at slower speeds. It seemed to always be shuffling about when there was no need. Nothing wrong with the ZF6 - properly plant it and it will kick down fine. It might be fractions of a second slower to actually shift but it's not that bad.

I find similar complaints with our DSG 7-speed as the ZF8 that preceded it - it's actually remarkably dimwitted at times, and at other times hugely over agressive. Yes it might be impressive when you've launched yourself to a ton in no time, but in everyday urban driving it's often quite annoying.

I’ve had a ZF6 in a 330, a ZF8 in an M140i and am now back with a ZF6 in my 335i.

I never noticed my ZF8 shuffling about at lower speeds, I really liked it. It’s a much more responsive gearbox but I did find 8 gears was too much when using the paddles. I think it’d have been better with a head up display so you could see what gear you were in more easily.

By comparison I find the ZF6 pretty dimwitted at times, even is sport. I’ll often override it with the paddles.

Whilst a big fan of the ZF8, I’ve only ever driven it when mated to a bigger engine (my M140i, 330d, 335d). I don’t know if it’s feel different with a smaller engine.

Personally I prefer BMW’s DCT over both.

I've not noticed shuffling either but I have heard complaints about it from someone I know who drives a lot of 520d so maybe it's a diesel thing, taking advantage of that narrow torque band :P

8gears too much agree but if I'm on a jolly I find I only use 2-5 anyway before I'm looking at the speedo.

Not driven the dct properly tbh but the lack of creep makes me think twice about them as my drive has very awkward narrow points.

Either way each to their own. I prefer 8spd to the 6spd auto but would prefer a 6spd manual approx 10% of the time over both.

[cerb4.5lee]

bmwmike said:

Court_S said:

Swervin_Mervin said:

I don't like the ZF8. And I prefer the ZF6.

I might be mental, but that's based on having lived with both. The ZF8 I found too fussy - especially at slower speeds. It seemed to always be shuffling about when there was no need. Nothing wrong with the ZF6 - properly plant it and it will kick down fine. It might be fractions of a second slower to actually shift but it's not that bad.

I find similar complaints with our DSG 7-speed as the ZF8 that preceded it - it's actually remarkably dimwitted at times, and at other times hugely over agressive. Yes it might be impressive when you've launched yourself to a ton in no time, but in everyday urban driving it's often quite annoying.

I’ve had a ZF6 in a 330, a ZF8 in an M140i and am now back with a ZF6 in my 335i.

I never noticed my ZF8 shuffling about at lower speeds, I really liked it. It’s a much more responsive gearbox but I did find 8 gears was too much when using the paddles. I think it’d have been better with a head up display so you could see what gear you were in more easily.

By comparison I find the ZF6 pretty dimwitted at times, even is sport. I’ll often override it with the paddles.

Whilst a big fan of the ZF8, I’ve only ever driven it when mated to a bigger engine (my M140i, 330d, 335d). I don’t know if it’s feel different with a smaller engine.

Personally I prefer BMW’s DCT over both.

I've not noticed shuffling either but I have heard complaints about it from someone I know who drives a lot of 520d so maybe it's a diesel thing, taking advantage of that narrow torque band :P

8gears too much agree but if I'm on a jolly I find I only use 2-5 anyway before I'm looking at the speedo.

Not driven the dct properly tbh but the lack of creep makes me think twice about them as my drive has very awkward narrow points.

Either way each to their own. I prefer 8spd to the 6spd auto but would prefer a 6spd manual approx 10% of the time over both.

I really liked the ZF8 in the F13 640d and I thought that it was a really good match to the engine. I wasn't sure if I would like the DCT in the F82 M4 at first, but now I love it and I think that it really suits the car(originally I would've liked it with a manual gearbox though).

The auto in the Merc has 9 gears but that doesn't bother me because I never use the paddles, and I just leave it to do its own thing.

Like Sam I've always found the ZF6 to be a bit dimwitted, and I've had that gearbox in the E90 330d/330i/X5 4.8iS.

[sam.rog]

I’ve got both. The zf8 in my g20 330e and a zf6 in my e91 330d. The zf8 is superior in every way. I’ve never noticed it shifting. Perhaps the electric motor helps.

The zf6 is a good gearbox, but definitely feels its age compared to the zf8. Apparently a xhp gearbox map improves the zf6. Im tempted to try it but don’t want to put undue stress on a 90k mile gearbox.

[cerb4.5lee]

sam.rog said:

I’ve got both. The zf8 in my g20 330e and a zf6 in my e91 330d. The zf8 is superior in every way. I’ve never noticed it shifting. Perhaps the electric motor helps.

The zf6 is a good gearbox, but definitely feels its age compared to the zf8. Apparently a xhp gearbox map improves the zf6. Im tempted to try it but don’t want to put undue stress on a 90k mile gearbox.

I thought the ZF6 matched the more torquey engines in the E90 330d/X5 4.8iS better than it did in the E90 330i. I always hankered after a manual gearbox in the 330i, and I think a manual would suit the revvy nature of the N52 much better.

The ZF8 is a great gearbox I reckon, and I think that it is my favorite of all the slushers I've experienced.

[Swervin_Mervin]

I know I'm out on my own on the ZF8, but we can only go off our own experiences I guess. It was in our 125i (4 pot turbo) and like I say had the Sport Auto mapping. It was a 2012 car so fairly early on in the ZF8 usage - maybe that had something to do with it.

I'm still not convinced it would suit the N52 though - as Gunk says above, these cars aren't performance models. And when you're not on it, the ZF6 absolutely suits it down to the ground.

[cerb4.5lee]

Swervin_Mervin said:

I'm still not convinced it would suit the N52 though - as Gunk says above, these cars aren't performance models. And when you're not on it, the ZF6 absolutely suits it down to the ground.

That was where I got to with my E90 330i auto. I purchased it because I knew that it would be a great all round car(which it was), and I didn't treat it as a performance car and I mostly cruised around in it(which it was brilliant at). The ZF6 suited the cars slightly laid back nature I thought in that regard.

I miss the N52 engines smoothness a lot, because the 3.7 V6 NA engine in the 370Z is pretty rough in comparison(especially at around 6k rpm). The N52 would rev completely out with ease, whereas the VQ engine is properly reluctant at high revs in comparison.

[bmwmike]

cerb4.5lee said:

I miss the N52 engines smoothness a lot, because the 3.7 V6 NA engine in the 370Z is pretty rough in comparison(especially at around 6k rpm). The N52 would rev completely out with ease, whereas the VQ engine is properly reluctant at high revs in comparison.

That's interesting. Wonder why... Is it the imbalance of the V6 or just a bit strangled would you say?

[cerb4.5lee]

bmwmike said:

That's interesting. Wonder why... Is it the imbalance of the V6 or just a bit strangled would you say?

I think that Nissan should've kept the VQ engine lower revving like they did in the early 350Zs. In my 370Z it redlines at 7500rpm, but with Nissan doing that it has lost all the smoothness after about 6000rpm I reckon. It is lovely and smooth at lower revs, but it is quite disappointing to use at high revs though for me.

[pmorg4]

I had a 350Z years ago and I recall it was never a particularly keen engine if that makes sense, although it did sound nice at lower revs. Totally different character to the N52 which encourages you to rev it out.

[Court_S]

Swervin_Mervin said:

I know I'm out on my own on the ZF8, but we can only go off our own experiences I guess. It was in our 125i (4 pot turbo) and like I say had the Sport Auto mapping. It was a 2012 car so fairly early on in the ZF8 usage - maybe that had something to do with it.

I'm still not convinced it would suit the N52 though - as Gunk says above, these cars aren't performance models. And when you're not on it, the ZF6 absolutely suits it down to the ground.

I wonder how much the age has to do with it; my 140i was a late car which I believe had a softer gearbox map which made it much smoother even in Sport Plus. It was notably less aggressive than the 2018 car I drove.

I didn’t mind the ZF6 in my 330 until I had an F30 330d with the ZF8 which for me highlighted the shortcomings. They’re less noticeable in my current 335i in 90% of situations, but there are times when it bugs me.

[sam.rog]

I think the more powerful or torquey the engine the less the gearbox matters.

[cerb4.5lee]

sam.rog said:

I think the more powerful or torquey the engine the less the gearbox matters.

That is where I've got to with the F82 M4 as well. It is a pretty quick car...so I like the fact that it has a pretty quick gearbox(DCT).

The M4 makes my manual 370Z feel very old school, plus the 370 doesn't feel all that quick either in comparison(they both weigh about the same so you notice the difference even more I reckon).

[g3org3y]

g3org3y said:

Something not 100% with the E91 at the moment and I'm not too sure.

Idle could be smoother IMO, occasionally can feel a bit 'pulsey' if that makes sense. Seems to be worse when the car is hot.

I've also had one or two weird situations when I've nailed the throttle to nip out for a gap and it's as though the power has been totally cut (not because of the traction control I hasten to add). Seems to be especially if doing right hand turns out of a junction (happened on x3 occasions in last number of months, but also 1x for straight across). If at standstill and I give the throttle a stab, the rev rise is almost a 'double pulse' if that makes sense. That is intermittent and typically if the idle is slightly rougher.

Could it be a MAF issue?

The only codes I've got are: 29F5 and 29F4. (catalytic-converter conversion & catalytic-converter conversion 2) No EML. I think these codes have been present since I had the issue with the oxygen sensor (which was changed), and that was causing an EML. I can clear the codes, but then they can come back.

EML on Friday...(and 158k miles exactly!)



Only codes continue to be 29F5 and 29F4

Used the C310 to look at some live data. Checked the 'Smooth Running' datastream...

Looks like a problem with Cylinder 5. All the others are within the tolerance of +/-200. I understand the closer to zero the better.





Cylinder 5 values was out of tolerance and fluctuating quite significantly...




Replaced all x6 coils last year with new Bosch ones. Also I think spark plugs done not that long ago. If I get the chance, I'll get the plug out and have a look at the condition.

Isolated injector issue? What do you guys reckon. The engine only seems to be a bit rough at idle and when the idle is low (700ish).



Give it a touch of gas and bring the idle to 800+ and it's fine. During driving, it's fine - revs to red line, not down on power at all.

[JakeT]

Air conditioning on or off? Any hard starting?

I’d probably do the usual checks, and swap bits between cylinders, and then pass it on to a specialist to look at.

[Swervin_Mervin]

All sounds exactly like mine was. Replaced coils and plugs and smooth running was still out of tolerance on a couple of cylinders.

Have you checked the DME yet? Might not be wet at the mo with the dry weather but you might be able to check the board for damage?

[g3org3y]

JakeT said:

Air conditioning on or off? Any hard starting?

I’d probably do the usual checks, and swap bits between cylinders, and then pass it on to a specialist to look at.

I'm not sure how much of a difference the A/C makes. When I turn it off, it shuts off the fan so often that makes things a bit smoother at idle (that fan is loud!)

No problems starting at all.

Swervin_Mervin said:

All sounds exactly like mine was. Replaced coils and plugs and smooth running was still out of tolerance on a couple of cylinders.

Have you checked the DME yet? Might not be wet at the mo with the dry weather but you might be able to check the board for damage?

I'll try and have a look. Extinguished the EML this morning, went for a drive. No issues. Been for another drive now (about an hour), EML came on after about 10 mins, normal driving. Same codes.

Is it just me, or is the N52 a HOT engine!?

[bmwmike]

g3org3y said:

I'll try and have a look. Extinguished the EML this morning, went for a drive. No issues. Been for another drive now (about an hour), EML came on after about 10 mins, normal driving. Same codes.

Is it just me, or is the N52 a HOT engine!?

They do run pretty hot, and the engine map affects it too hence the electric coolant pump. Hotter for efficiency when cruising and cooler when ragging it as more performance.

[g3org3y]

For N52 valve cover gasket replacement, IIRC you need to change all the bolts right?