My BMW Z4 (E89) Journey – 2 Year Transformation

This story starts a little different from most BMW owners. It didn’t start at a fancy dealership or even a used car lot. This car took many days of work, some frustration and lots of learning experiences to get here and I love it for it. So, let’s start from the beginning when this beauty showed up on a back of a truck, looking sad and broken, to now, 20,000 miles later and still bringing a smile to my face every time I drive it. I hope you enjoy this trip down the memory lane of my journey with the BMW Z4. If you hit that like button, I will even talk about my favorite things about this car I didn’t except!

I’m sure I’m not alone in this, but almost on daily bases I scroll through different website looking for cars I can’t afford or projects I should definitely not take on and wonder.. what would happen if I just bought it. One of those nights, I stumbled upon a few very blurry pictures of a BMW Z4 that was listed at an auction house and only had some ‘mechanical issues’. As not many people were bidding on it, I thought it was a perfect opportunity to get my hands on a very unique hard-top convertible. To be honest, I’ve never even seen one in real life before buying it. Hit that like button for buying cars sight unseen!

The rebuild:

I was scared and excited, I won a car at auction that I knew almost nothing about. A week later, a car hauler pulled up in front of my house and that’s the first time I saw this Z4. I could see the sexy curves of the body behind all of the dust and dirt and then I heard it start up as it was driven off the trailer. It sounded hurt, very hurt. With my very limited experience at the time, I was excited to jump in and get this engine repaired! After hours of Youtube videos and forums posts, I was convinced that the noise coming from the engine was timing chain related.

Attempting a timing chain replacement for the first time felt very ambitious and perhaps a little dumb, but what did I have to lose? After 2 weekend of work, I replaced the timing chain, the timing chain guides and sprockets and everything else along the way.. but when I started the engine, I heard the same knock, knock.. knock.

At that point I knew I mis-diagnosed the issue and the real issue with the engine was the famous rod knock.. which I later confirmed by taking the engine apart. Check that video out at the link in the description if you’d like to see the damage. The best course of action at this point was to get a replacement engine. Luckily I was able to source a 2015 engine with only about 30,000 miles on it for a very good price. This was the new plan, replace the engine. Surprisingly, engine replacement has gone smoothly and I honestly believe that it has given me a lot more confidence with working on cars in general and later on rebuild the BMW N55 engine.

When the engine fired up for the first time, missing it’s intake and exhaust and still barely attached to the car. I was on cloud nine and figured I’ve done the hardest part.. but of course, it’s not so easy. What I failed to realize is that there are many N20 engine variations. For the longest time, I had lean codes that I just couldn’t figure out. I replaced the HPFP and fuel sensors, tested for vacuum leaks using a smoke machine, replaced various other sensors and even put a new set of sparkplugs and coils, but my lean code remained. This is when I learned more about the differences between different year N20 engines. Turns out, BMW has upgraded the injectors from EU5 to EU6 sometime between when the Z4 was manufactured and when the donor engine was produced. I installed the old injectors into the new engine viola! No more lean codes! If you are doing something like this, you will also have to replace the Oil sensor and the HPFP has a different connector.

With the engine running like a champ, I started fixing many other little items on the car and cleaning everything I could. One of the items that I knew had to be done was to service the hardtop roof. It’s super important that these are very well maintained as repairing one of these is not easy at all. How hard is it? I called my local BMW dealers and out of 3, only 2 would even take a look at it. Anyway, I have a full video on how to properly lubricate all of the moving parts and moisturize the rubbers so it doesn’t leak and squeak.

One issue I still have with the engine is hesitation or failure to start up when the engine is fully warmed up. I’ve tried over 20 different items to narrow this down and have found nothing. I won’t go too much into it as I’m planning on making a video about this in the near feature, so subscribe and see what happens!

The Mods:

Even though I enjoyed how the car looked stock, I wanted to make it a little more my style. So, I did what everyone else has done on their Z4s and replaced the front grill from chrome to black and installed white LEDs to modernize the front end a little bit. I then installed a body color spoiler to lift up the back end as well. After the spoiler I tinted the windows for that slick hard top roof and even though I debated whether I should or shouldn’t tint a convertible, I love it! Since my Z4 is pre-LCI, I also decided to swap out the old blub looking side indicators for newer style chrome ones and painted the side reflector body color. These two modifications changed the side profile and gave the car a sleeker look. 

The biggest difference as far as style was done by the new wheel and tire combination. I went for the M437 style rim that normally comes on a BMW M3 and M4. I was surprised that my little Z4 happily accepted 19 by 9s on the front and 19 by 10s on the back. I had the wheels wrapped in some Nitto tires and this combination has been a dream ever since. Never rubbed and the ride has been decent as well. I must say, this has been my favorite change on the car and I love how it completely transforms the look. Later-on I converted to studs for ease of changing the wheels and tires to the winter set and this is what it looks like now.

Since I didn’t want to drill my intact front bumper, I installed some magnets behind the bumper cover and modified the license plate bracket as well and now I had a removable license plate I could use when parking on the streets.

For a while, I left it alone and just enjoyed driving the car, but then I had an itch that needed to be scratched. I wanted better sound out of the exhaust. I started by deleting the resonator and replacing it with a super sprint stainless steel pipe. It definitely made a difference and added many pops and burbles. Half a year later, I upgraded it further with a super sprint sport muffler and now she sounds just perfect.. well, at least for a 4 cylinder turbo engine.

Driving:

And here we are.. after all of the stuff I have fixed, upgraded and updated.. what have I been doing with the car lately? Well, we have had a beautiful summer and I enjoyed it taking it on long drives into the country, city and just around the neighborhood. If you truly enjoy driving and a car is more to you than just an appliance, this Z4 will keep you engaged and having fun while the sun shines down on you and the wind blows through your hair. I like that it doesn’t pretend to be a hardcore, aggressive sports car. It’s a sport, fun to drive grad tourer.

Conclusion\Future Plans:

To finish off the video, let’s quickly look into the future plans and what I want to do with this car. To start off, this is a long-term car for me. I’m not selling it any time soon, so expect to see it on this channel for years to come. I will get the startup issue fixed on it, hopefully sooner than later and I’m also planning on installing an Apple CarPlay system to bring the infotainment department into 21st century, but the good ones are at least $750 at the moment and I’m not sure it’s worth it. I mostly focus on driving and enjoy nature when I’m in this car, but I also like the convivence it provides. Either way, after two years of ownership and two years of videos, let’s continue this journey for many more! I hope you stayed tuned by subscribing and leave some ideas for me as well down in the comments. On that note, thank you guys so much for watching, I really appreciate it and I’ll see you in the next one.