motoroller
Member
I thought I'd add some pictures of my build log here. It's not so much of a build - more of a revival, saving this car from being scrapped.
A bit of history: a few years ago I owned a Z4 2.0i M sport, and enjoyed it but it was definitely lacking a bit on power compared to other cars I've had (V6 and V8s).
Sight unseen, I bought this Z4 2.5i at auction and drove it back about 100 miles. Alarm bells started ringing when the soft top didn't work, windows didn't work and there were lots of clunks from the front suspension accompanied by serious tramlining. Oh, and having to top up water several times on the way home. And the airbag light was on. Felt like I'd bought an ultimate lemon...
I drove it about 50 miles after bringing it home, topping up every stop (lol). I then broke down on the way home while watching the custom digital temperature gauge, which spurred me into action on the car.
I started by replacing the thermostat - it was obvious someone had undone this and not done a good job of putting it back in. Used thermostat and new gasked and temperatures on the BMW digital gauge were much more sensible.
I snapped the temperature sensor in the process of replacing the thermostat, but it was an aftermarket part so it was replaced with original BMW.
Remember: vaseline on the plastic connectors makes undoing them a lot easier. After more testing, the radiator and expansion tank were replaced too. Temperatures were now stable and no water system leaks, the engine felt like a peach not a lemon. Now on to the other faults...
The next thing to do was to get a fresh MOT (only 6 odd weeks left at the point when I bought it). This is an easy way for me to know what needs doing from a safety standpoint and at the same time, given that I knew a couple of jobs were needed I could double check the MOT testers attention to detail.
It failed MOT on the front suspension bushes, handbrake and airbag light. Advisory of rear tyres but those always need replacing
Front suspension bushes were easy enough, got genuine BMW parts
Handbrake was a pain. One of the problems was that the ratchet mechanism felt very strange, and non-uniform. I removed the exhaust and propshaft, all the interior trim to access the handbrake, took out the seats for a deep clean, pressure washed the carpets outside the car, and re-ground some teeth into the handbrake mechanism. Put all that together and the handbrake felt much better.
Mid-disassembly
Took the opportunity to give the seats and carpets a good clean indoors away from the cold!!
Before
After
I should have called the MOT testers and clarified why the handbrake was an issue before doing this in hindsight. When I went in for a retest, it was the same issue as before! I asked them why, they said it was the difference in efficiency from left to right that caused it to fail. D'oh.
In the process of undoing all this the downpipe bolts sheared when taking the exhaust off. It was like driving around on straight pipes, such a glorious sound but then this came up on the MOT as an issue.
Heating the bolts to begin with helps, as it softens them and expands them properly into the push fitting on the exhaust flange. It also helped the nuts break off during hammering so the whole nut/bolt assembly could fit through the flange hole.
Bingo!
The handbrake bell housings were undone too, which showed lots of rust. The car had been sitting for a while but I adjusted and bedded them in as per BMW service manual (handbrake on briefly at 40km/h). Removed all dust and grime from the inside of the housings:
Now the car is MOT'd and is my daily driver. The remaining niggles are windows, roof and sound system.
Luckily I did the roof motor work on my previous Z4 so had a good idea of what to do. As the motor was corroded so badly and I didn't want to be undoing all the roof mechanism again (car is stored outdoors), I relocated the pump to the boot without a motor for now.
Motor:
Blocked plenums being unblocked:
The sound system really is terrible, so temporarily I've added in a Helix DSP/amplifier on a plug-and-play harness and this has improved things drastically,
So all in all - a lot of effort but this Z4 has been brought back to life! Now to slowly work on the rough bodywork... oh and fix the awful ICE.
After a quick polish:
Two options: sell this one now it's all running fine and buy a 3.0si, or keep working on this one as it has the iconic M54.
A bit of history: a few years ago I owned a Z4 2.0i M sport, and enjoyed it but it was definitely lacking a bit on power compared to other cars I've had (V6 and V8s).
Sight unseen, I bought this Z4 2.5i at auction and drove it back about 100 miles. Alarm bells started ringing when the soft top didn't work, windows didn't work and there were lots of clunks from the front suspension accompanied by serious tramlining. Oh, and having to top up water several times on the way home. And the airbag light was on. Felt like I'd bought an ultimate lemon...
I drove it about 50 miles after bringing it home, topping up every stop (lol). I then broke down on the way home while watching the custom digital temperature gauge, which spurred me into action on the car.
I started by replacing the thermostat - it was obvious someone had undone this and not done a good job of putting it back in. Used thermostat and new gasked and temperatures on the BMW digital gauge were much more sensible.
I snapped the temperature sensor in the process of replacing the thermostat, but it was an aftermarket part so it was replaced with original BMW.
Remember: vaseline on the plastic connectors makes undoing them a lot easier. After more testing, the radiator and expansion tank were replaced too. Temperatures were now stable and no water system leaks, the engine felt like a peach not a lemon. Now on to the other faults...
The next thing to do was to get a fresh MOT (only 6 odd weeks left at the point when I bought it). This is an easy way for me to know what needs doing from a safety standpoint and at the same time, given that I knew a couple of jobs were needed I could double check the MOT testers attention to detail.
It failed MOT on the front suspension bushes, handbrake and airbag light. Advisory of rear tyres but those always need replacing
Front suspension bushes were easy enough, got genuine BMW parts
Handbrake was a pain. One of the problems was that the ratchet mechanism felt very strange, and non-uniform. I removed the exhaust and propshaft, all the interior trim to access the handbrake, took out the seats for a deep clean, pressure washed the carpets outside the car, and re-ground some teeth into the handbrake mechanism. Put all that together and the handbrake felt much better.
Mid-disassembly
Took the opportunity to give the seats and carpets a good clean indoors away from the cold!!
Before
After
I should have called the MOT testers and clarified why the handbrake was an issue before doing this in hindsight. When I went in for a retest, it was the same issue as before! I asked them why, they said it was the difference in efficiency from left to right that caused it to fail. D'oh.
In the process of undoing all this the downpipe bolts sheared when taking the exhaust off. It was like driving around on straight pipes, such a glorious sound but then this came up on the MOT as an issue.
Heating the bolts to begin with helps, as it softens them and expands them properly into the push fitting on the exhaust flange. It also helped the nuts break off during hammering so the whole nut/bolt assembly could fit through the flange hole.
Bingo!
The handbrake bell housings were undone too, which showed lots of rust. The car had been sitting for a while but I adjusted and bedded them in as per BMW service manual (handbrake on briefly at 40km/h). Removed all dust and grime from the inside of the housings:
Now the car is MOT'd and is my daily driver. The remaining niggles are windows, roof and sound system.
Luckily I did the roof motor work on my previous Z4 so had a good idea of what to do. As the motor was corroded so badly and I didn't want to be undoing all the roof mechanism again (car is stored outdoors), I relocated the pump to the boot without a motor for now.
Motor:
Blocked plenums being unblocked:
The sound system really is terrible, so temporarily I've added in a Helix DSP/amplifier on a plug-and-play harness and this has improved things drastically,
So all in all - a lot of effort but this Z4 has been brought back to life! Now to slowly work on the rough bodywork... oh and fix the awful ICE.
After a quick polish:
Two options: sell this one now it's all running fine and buy a 3.0si, or keep working on this one as it has the iconic M54.
bought sight unseen so I guess you expected some work - just not quite so much 
