BMW Z4 Common problems. E85/86

[sumpcracker]

I have started a thread with this title because when this title is put into google not much of any use comes up.
There are threads which cover some of the items if you do a search, but its not as good as a heads up for those doing the search before potential purchase.
I have bought and sold many Z4 E85/86 as well as running a few of my own. I also look after a few for servicing and repairs.
I'd have been happy to have found this thread when buying my first Z.

There are quite a few items I could list, but these have been present on most cars I have seen.
I have not included M cars as I have not tangled with any aside from test drives.
I'm not putting the E85/86 down, as its a great car, i'd say its the best all round sports car out there at the moment, but the owners tend to love their cars so much its hard to find the negative info.
I'm sure I will get the standard friction from the forum hero's, but maybe you could add to the list?

1) Rusty brake lines, quite a serious issue and doesn't seem to be relevant of age or mileage, I have replaced the rear set on a 36,000 car and most early cars need doing. My 2007 90k car is not bad enough to replace them, but if left as they were id give them a couple of winters.. If you have good ones it is a good idea to cover them in grease/spray grease to keep them coated from the elements. The problem is mostly at the rear, best seen with car on a ramp.

2) Broken rear springs, these break at the pigtail and again, not easy to see unless the car is raised, you may be able to feel the end of the spring if laying on the floor.

3) Headlights, these are pretty poor unless xenon equipped. The first Z4 I drove in the dark was a shock, worst lights I have seen on a modern car. A common upgrade is HIDs which are good but uprated bulbs make a difference, the problem on quite a few cars is made worse by the lenses being faded/glazed/matted. 2 hrs with some 1200 wet and dry paper and polishing compound can make them like new.

4) Mirror glasses fall out, The glass falls off the backing, and if you are unlucky - smashes on the floor.
Best to give them a pull/wiggle when you get the car and see if they are loose, if they are, remove and re glue, I use tiger seal.

5)Hood motors... I don't need to say this really, but in case you missed it - hood motors, water drains block, motor gets wet and dies... expensive fix and a bitch to DIY. On the subject of hoods, I have seen a couple of bent hood frames, (this may be where they have been forced shut) this is also a complex repair so unless its bargain of the century, id avoid.

6) Transmisson, not that anything fails often here, but a clunk when reversing after going forward is there on most cars from the diff input area, there are quite a few general transmission noises on higher mileage cars, slight flywheel rattle on idle can be heard, possible gearbox chatter too. The flywheels can rattle as you switch off the engine - depending on how severe, its not really anything that needs addressing, I have yet to see anything NEED doing aside from worn clutches. On a side note, the 6 speed cars don't feel great selecting 1st and 2nd gear, quite a clunker in a lot of cases. Also worth removing the clutch delay valve for nicer feel and longer lasting clutch, there will be a guide on this forum for DIY.

7) Poor handbrakes, bit of an obvious one but common - you can tell just how well the cars been serviced when it has full stamps in the book but the handbrake is facing the moon, just look at the interior pics of the cars for sale, it takes under an hour to adjust to a 2/3 click locker, so it shows you how little attention has been paid when its overlooked, also annoying when the car rolls away on 6 clicks.

8 ) Broken exhaust hangers, (forget which models this affects but its happened on both my coupes) the rear left hanger breaks off the rear exhaust box and rattles around, on my last car the box jumped out of the rubbers and fell down because of this. Its stainless steel so not and simple to get welded back on. Never ask how much a genuine new rear box is because you will die.

9) Foot well speakers, on cars with amplified foot well speakers the amp decides to turn on and off intermittently, usually the less power input the less likely they work, so turn up the stereo loud and they cut in. I am not sure there is a simple fit for this aside from bypassing the amp and running the speakers on their own.

10) Wiper motors, only seen this on 2003-2005 cars but it could be all of them. Wiper motor intermittent wipe fails/stalls, or in worst cases wipers fail all together. This is due to tiny bits of metal getting into the motors grease as it wears and making the grease on the contact strip conduct, ending the motors travel. Its a simple DIY strip down/clean re grease fix, I am sure there will be a guide on this forum, if not I can do one.

11) Fog lights on facelift cars, usually the reflector has become mould/mess and the lamp appears grey. They will probably still work and not relevant for MOT, and due to the size and location they do not look untidy, but they are about 80% more effective when replaced or repaired.


I will edit add/correct if I think of anything, but in summary-

There are no major fails, (which is more than I can say for its Boxster rival, engines much?) the only time I have seen a breakdown on a Z4 in all my years as a mechanic was a fuel pump relay on a 2003 car, water pumps are often overlooked but if a car has been serviced correctly it will have been replaced (check history). Things like Vanos soloinoids, cam sensors and on SIs the eccentric sensors can fail but none of that is common and won't leave you stranded anyway, its a well thought out very reliable car, with decent MPG and holding onto its value better than most.

[sumpcracker]

12) Window regulator cables/window fail.. seem to be getting more common with age -
Do not buy a Ebay repair kit, buy a full used regulator or new one, if the car you are buying makes a scrape noise from inside the door the cable is going to fail soon, you may find one day the window will not come back up - I am sure it will be raining that day. Regulators are around £150 new and £50ish used.

[cj10jeeper]

Nice thread and some useful details fro people searching common problems.
I'm not sure agree with point 7 though. The handbrake is not a common 'problem' and clearly all pass the MOT each year. It's not like others listed that are inherent weaknesses or faults such as failed roof motors, wiper issues, rusting rear brake lines. This is just lack of maintenance or adjustment by lazy owners.

You could also add:

Centre rear brake light that cracks, especially near the ends/corners, due to overtightened springs and a flawed design. Easily replaced and BMW now supply softer fitting springs.

Corroding 108 style rims. Caused by being split rim and getting water ingress. BMW introduced a superior design with plstic coated innr, but still fails to resolve the issue. Refurb every few years is the solution, although beads of silicone can delay the issue

Vanos is a longer lifetime issue and repaired with a service kit.

[sumpcracker]

Thanks for adding, I forgot about the brake light!

As for the hand brake, no it's not a weak point but I'm surprised how many cars have so much travel and claim a full service history, Any decent mechanic doing a service will adjust it, its a point of reference for how the cars been looked after to me, you can't dip the oil on a lot of them, oil filter is an element, so you can only really check the air filter for eevidence of service.
Some garages will just change the oil and stamp the book, some will not even do that, car perverts like us do not want a car like that, for a novice there is little to see other than the handbrake

[markplant]

Roof motor

[hopz121]

Lollipop bushes
RTAB
Sticky steering
Disa valve
Rocker cover gasket
Water ingress in boot floor by amp
Water ingress in front lights

Just to name a few but let's forget about things that can go wrong all cars have faults

[un1eash]

Cracked exhaust manifold on the 2.0i seems to pop up every now and then.

[paddy wright]

Good thread to help new owners- could add the leak on passenger door membranes.

[GuidoK]

As for the wiper mechanism, it's usually one of the plastic ball links that fail. They are not sold seperately, so you need either a new mechanism or some other kind of repair like the wiper linkeage repair clip

Also the noises coming from the driveline are not that bad. They mostly get noticed because you're driving a convertible.

Best thing is that now that the sticky steering has a permanent free solution, virtually all the problems that can arise are either cheaply solved (like vanosrings instead of the stealer having installed a completely new vanos) or are preventeable (water in the boot and such stuff), that is: if you do your homework and are prepared to get your hands dirty. For those who don't want to do that: they deserve to pay

There are no horrorstories like on porsches where complete engineblocks crack by the masses etc.

[enzed4]

Best thing is that now that the sticky steering has a permanent free solution.

What's that then?

[Spikey]

Good thread - perhaps add the rusting tailgate on the Coupe - again not all are affected but if you are looking to buy you would want to check this

[dhobbs]

From my own experience:
Headlight washers (both sides)
Rear parking sensor
xenon ballast
door membrane (repaired whilst installing door speakers)
Mirror glass (luckily I caught it)
Boot lid rust (repaired under warranty)
Rear heated window, a couple of bars not working. Thankfully whole roof replaced under warranty.

But a bloody good car for the money, performance, looks and whole experience.

[hughmungus]

My input on this great thread:
Water in the headlights- cheap fix if you have time
Light out warning light again cheap fix just time checking all bulbs
Rear Parking sensor -still not figured out whats wrong
Tramlining from Run Flats

[Paulj100]

Best thing is that now that the sticky steering has a permanent free solution.

What's that then?

+1. What's the fix?



Paul

[Mike6]

As a Newbie, I would also suggest everyone checks their DISA unit. There are guides on here which made the task really easy. Failure of this part can be game over for the engine.
I would also suggest the rubber pipe from the servo unit which is prone to collapse - replacements as hopefully I am about to find out are in harder material.