Guide before you buy
The aim of this section is to get you familiar with the different element you will have to look at when buying a Z3, in order to avoid bad surprises.

Well known Z3 issues
Don't be affraid, as it is very unlikely that all those issures happen to your car. However some could, so pay close attention!

Fuel gauge / level
Problem: The gauge starts being very imprecise or even stop measuring the fuel, showing 0 even when the tank is full. It is located behind the passenger seat, behin the carpet. If this carpet piece is cut, it means that this has already been addressed.
Solution: You have to change the mechanism (showed on the picture).


Rocking seats
Problem:Typicall Z3 issue, with time the seats getting looseness and move forward and backward, when you brake or accelerate. It is not dangerous but quite annoying. This is due to some small plastic bits that lay inside the seat rail.
Solution: Changing those plastic bits, problem is solved. It is not so complicated, but annoying as you have to remove the whole seat and take the rail appart.


Damaged sport seats bolster
Problem: due to its shape, it gets damaged with time by coming in and out of the car. This is also a good indication of potential mileage. The blue car on the picture should have 110-140.000km, according to the bolster condition.Unless it has been really not taken car of...
Solution: Nothing major, you could do an upholstery job. You can also remove the leather and improve the foam under it, to give the shape back to the seat.


Slow windows
Problem: With time, the windows mechanim starts failing and slowing the window operation, until the mechanism finally completely fails and stops working.
Solution: One intermediate solution is to grease the mechanims. You should do that every 2 years or so. That said, if the mechanims brakes, you'll have to change it completely.


Airbag light
Problem: The airbag light does not go off. This tipically happens when you remove a seat without disconnecting the battery. This doesnt mean that the airbag will not work in case of crash, but you better go to the dealer to get it checked.
Solution: The dealer will turn it of for a low amount of money, or even free of charge. You can also buy a Carsoft connector and program to plug into your diagnosis socket and reset the light yourself.

Camshaft sensor
Problem: When you turn the car on while hot, it may show signs of stalling. Also, you will notice less power at all speeds, a kind of lazy acceleration. It could even stall.
Solution: Changing the sensor, about 130€ in BMW.

Rear differential mounting and trunk floor welding
Problem: This happens in almost all ///M cars due to the power that is applied on the chassis. It seems to be more likely to happen on lowered cars as well. The differential mount can start cracking, and the welding coming off. It is "The" most dangerous / expensive Z3 problem. It is quite easy to spot if you elevate the car (first picture), or if you look at the trunk floor for loose welding. (blue picture). Definitely to be lloked at on +80.000km cars. Las picture is the worse that can happen, it is unlikely to get to this point without noticing...
Solution: Taking the problem on time. For the welding, weld the loose points. You could also weld new mounts for the differential, or buy a special reinforcing kit made by our american friends (Randy forbes)

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Problem: The thermostat doesn't work correctly, and overcools / overheats the engine. With time this could damage the engine. It can be spotted if the temperature gauge is not perfectly in the middle (90ºC).
Solution: Change the thermostat (avg. 200eur). If you do that I also recommend taking the opportunity to change the water pump.

Soft-top and rear window
Problem: With time and weather, the rubber between the soft-top and the window may fail and lift off. It affects aesthetics, but also might get water inside the car. With time, the soft-top might also brake on that spot.
Solution: If it's not very advanced, you can just change the rear window. If it's more advanced, you will have to do some stitching! On extreme cases, you will have to change the whole roof (800€) + window (200€) + labor (1.000€). An example of stitching on the right pictures.