Some newbie Technical help needed please.

[jimmyh]

Firstly Hi All.

I am as above a newbie to Z3's. I recently bought a 2.8 which is turning into something of a project car as I am a bit obsessive. So far it has had new disks and pads all round new rear springs etc etc.

Today I replaced the serpentine belt. Very chuffed with myself and super easy ish aside from A: I did it without removing the fan and B: i had a moment of stupidity and put the wrench through the belt to turn the tensioner to put the new belt on.

I sadly have to confess to being slightly stumped on how to get past that problem for a minute or two. I then had a lightblub facepalm moment and realised what a plank i was being and hey presto 2 minutes later the belt was on.

I now have 3 further problems to deal with that I am hoping I can get some help on.

1st. The car has started stalling randomly when cold and seems to have a very minor misfire when warm idling. I know the MAF boot is split as they are want to do so am aiming to replace that tomorrow. I have also had the timing sensor replaced.
Checking for codes I am getting none however I seem to be getting quite random and sporadic o2 sensor readings using my wifi OBDii dongle??
If replacing MAF pipe does not fix it what else could it be? O2 sensor? Vanos?

2nd. I have noticed my cigarette lighter and passenger front seat do not work. Are they related in any way cannot remember fuse layout? The seat makes no noise in any motion direction and does not move backwards forwards up or down. I tried replacing the fuse (albeit with the battery connected but ignition off) and it arced as I tried to insert a new one so i stepped back so as not f anything up? Any ideas?

3rd an finally the mystery noise duh du duuuuuuuh!!!! So when going through the gears there is a noise described a bit like a rattly riflebolt action. I had a bmw specialist look at the car and they could see nothing obvious causing the fault. I have noticed however that the gearshift seems to stick if you pull it over to 5th gear.

If you put the clutch in and pull across to 5th but dont push forwards into fifth and then release it does not happily move back to neutral when released it takes a few seconds to uncatch and pop back into normal centre shift position. I cannot quite trace the source of the noise to front or rear of the car and havent had it up on a ramp personally to look yet.

Any and all help will be much appreciated.

[bertiejaffa]

Hi Welcome to the Forum - Im sure someone will be along shortly who has experience of fixing the issues you are seeing, however from other threads I have read over the past couple of years..

Misfire and rough running - definitely look for holes in the air intake pipes - I would also consider that one of the coils might need replacing before changing the Vanos - I had to have a coil replaced on my 2.0l when I bought it and the misfire only happened once for about 10 minutes. The lighter and seats are on seperate fuses. It could well be that the motor on the passenger seat is just duff - there are a number of threads on here about them getting stuck or breaking (even not moving because of rubbish under them. Finally the gearbox - changing the gearbox oil is always recommended and makes the shift much easier, after this there can sometimes be issues with the pins in the gearbox that need refurbishing - this is a much bigger job so I would go for the oil change first.

Hope that helps - I await Southernboy to tell me where I am wrong

[jimmyh]

TA. A gearbox flush is on the cards as soon as I can release the funds for it and as soon as I can decide whether to try DIY or just hand it to my mechanics.

[therealdb1]

Hi there,
I cannot really help with 2 or 3 without seeing / hearing the issues you describe but 1 will almost certainly be rectified by a replacement rubber boot.
Even a small split will let unmetered air in which will give mixture problems and cause you misfires, stalling and random lambda readings.
While you are in there with the main induction hoses out of the way check all of the other smaller ones too as unfortunately our cars are of a certain age now and all of the rubber bits are perishing.
As Bertiejaffa says fix the simple (and relatively cheap) things first before worrying what else may be wrong.

[Gazza]

I would agree with bertie on all he suggests, the seat problem could also be the switch panel packed up.

[jimmyh]

I have a bone to pick with all the Z owners...

Why The F did you not make it clear what a nightmare it is to change the elbow???

Took me the better part of 2 hours of faffing around and breaking a tool to swap out the old cracked unit for a new one.

The good new is its fited now and seems on the face of it to have sorted out most of the issues..

Next is a diff fluid change and a gearbox fluid change I think.

[bertiejaffa]

I have a bone to pick with all the Z owners...

Why The F did you not make it clear what a nightmare it is to change the elbow???

Took me the better part of 2 hours of faffing around and breaking a tool to swap out the old cracked unit for a new one.

The good new is its fited now and seems on the face of it to have sorted out most of the issues..

Next is a diff fluid change and a gearbox fluid change I think.

At this point I will pre-empt the next rant... refilling the gearbox is not easy due to the location (southernboy did it from the top with a clever use of homemade bottles. others use oil pumps)

[therealdb1]

If you think changing the rubber boot was difficult try changing a throttle body on a Jaguar XJR!!!
Sorry off topic there back to the Z3 I hope you never have to get the rear brake discs off when the handbrake shoes have delaminated inside them!
I'm glad the new bellows have sorted your running problems.

[Boosh]

Was gonna say about gearbox oil change: very easy job, only if you have good access and 'acme-style' syringe. Only one of the two, and the job becomes a royal PITA.
Still, glad you got other issue sorted. Niggles are more than made up for by top-down driving, especially this time of year, with the anticipation of nicer warmer weather...
Welcome to the forum,
Boosh.

[Alan W]

My 2.8 has had a similar issue ever since I bought it.. start it from cold and just leave it running and after a couple of minutes it will misfire a couple of times and then just cut out. However, if you get in and just drive it straight away it is fine. Additionally.. when it came back from the MOT yesterday I noticed that the engine wasn't ticking over smoothly.. it was slightly lumpy. I took it for a motorway blat and now seems to be ticking over smooth as silk again.

[jimmyh]

Thanks for the sympathy you sods..

Well interestingly the problem is still there. Started it from dead cold and it was doing its usual attempt to stall thing...

My issue now is I took it to a garage and I believe they replaced the timing? sensor about 8 months ago which was pretty damn expensive. Its also had new plugs, oil, filters etc in the last year and 5k miles...

As such I am not sure replacing any of those again will resolve the problem. It is odd that it only happens when cold. There is however a very minor misfire when warmhowever you really have to be on the ball to pick it up. If you open the door and rest your hand on the door glass as the car idles you can feel the small thump as it misfires.

I also think there may be a small leak from the cam cover gasket. Wish i had a bloody workshop. That way i could pull the cam cover off as well as the vanos unit (may as well while i am in there as it were) and replace all the seals and rebuild the vanos to prevent any vanos related issues. Actually frankly if i was doing that I would probably do the entire transmission as well.

[Southernboy]

First off, the misfire. This can be caused by a sticky valve lifter. Suggest you use an additive specifically for upper cylinder cleaning / lubrication. Next, how to "release" the stickiness...
1. take a drive to warm the motor. Once warm, accelerate beyond the top speed of 3rd gear by a little and then change down to 3rd again and let the clutch out. This will cause the engine to rev fairly hard, and force the engine oil to pump heavily into the cylinder head through the oil guides there. Do this 3 or 4 times. ( I was given the above method by a qualified BMW mechanic at a dealership)
2. The problem of cold starting. The Z3 has a fuel heating system. It is either a basic system which channels hot water through the throttle housing (there are 2 small rubber hoses attached to the throttle body on earlier cars) or it has an electrical system (later models). I would check these to ensure they are operational.
The problem could be also related to the misfire though. If you have a sticky lifter, it is also possible you have dirty / restricted injectors. A good injector cleaner additive will likely sort the dirty injector issue.
By the sound of it, the problem is a fuel supply problem at start up. Your car is fitted with an idle regulating valve positioned near the throttle body. (Check on realOEM.com). You might want to check the electrical connector to it to make sure it's clean and making good contact, or if the unit is working correctly. The item can be found under "fuel supply system" on realOEM.