Category Archives: Cars

Reviving the 3000gt

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A month or 2 ago, the 3000gt started making a weird noise. At first we couldn’t figure out what it was, but then I opened the timing belt cover and found there was no tension. Amazingly, the engine didn’t grenade, only jumping a tooth or 2. (lucky) Life got a little busy for a while, but when I got back to it, the problem wasn’t all that hard to fix. That’s not to say I didn’t run into any issues though. I learned a few things along the way as well, so I thought I’d document them here for anyone who finds themselves in a similar situation.

First, get yourself a copy of the service manual. The illustrations and step-by-step instructions will be helpful. Second, get a pair of cam sprocket locking tools for the 6g72 engine found in the 3000gt/Stealth/GTO. You’ll need these to immobilize the cams while working on the rest of the system. Third, make sure you have a supply of binder clips on hand. These are specifically called out in the manual and are definitely necessary. (3/4in or larger will do) If your car hasn’t had this service before, go ahead and buy a complete kit with the belt, pulleys, and a replacement water pump, seals & gaskets. The space is pretty tight to work in and you’ll likely not want to do this more than once. (the water pump is a common failure and seals and gaskets will all need replacing)

If you’re doing this at home, you’re going to need a number of tools to be successful:

  1. engine hoist/crane (needed to support the engine and allow removal of the driver’s side engine mount)
  2. load leveler (needed to lift the engine evenly)
  3. heavy duty impact driver (needed to remove the crank bolt from the pulley)
  4. mitsubishi/hyundai cam belt tensioner socket (needed to set the pre-load on the tensioner. you may also be able to get away with using a set of long right-angle snap ring pliers, but this will be more difficult. **mitsubishi/hyundai tensioner pulleys require a tool with 14mm pin spacing. VW/Audi tools look the same, but have 18mm spacing, so confirm it’s the right tool before you buy)

The service manual does make some assumptions and isn’t 100% comprehensive, so there’s a few things you can do to be prepared for that. First, rotate the engine until the timing marks on the cams are aligned. This should put piston 1 in the TDC or Top Dead Center position. Tip: If your belt was loose like mine was and 1 or more of the sprockets has jumped a few teeth on the belt, try to get as many of the other marks on the sprockets aligned with the marks on the head and block as possible. Then secure the belt to the sprockets that are aligned. (with binder clips) Use a box-end wrench to rotate the sprocket that’s out of position with one hand while you make slack on the belt with the other. When you have it in position, secure the belt to the now properly positioned sprocket with a binder clip. Putting the engine at TDC first will make everything easier when you replace the belt and pulleys.

6g72 cylinder layout

The cylinders in the 6g72 v6 engine are laid out with odd cylinders on the left and even on the right when facing the engine from driver’s side. (image is for a different orientation than the transverse mount in the 3000gt)

Second, before setting the pre-load on the new tensioner pulley, release the crank sprocket by adding slack to the timing belt around it and rotate the crank sprocket 2 teeth left of the timing mark. Pull the belt tight to the bottom of the crank sprocket leaving the slack above the sprocket. When you tension the belt, the pulley will pull enough slack out of the belt that it will rotate the crank sprocket clockwise. Doing this step in advance makes sure that when the slack is taken up, the crank sprocket will be in perfect alignment with the timing mark on the block. (if this works out differently for you, count how many teeth it’s off and adjust as necessary after loosening the tensioner and try again) Tip: don’t release the pin from the auto-tensioner until the tensioner pulley pre-load has been set and you’ve confirmed that all timing marks are aligned.

This job is definitely doable in a few hours if you’re well prepared. I’d also recommend having a helper if possible, but it’s not 100% necessary. The main difficulty is how tight the working space is and how crowded with parts it is. I had to redo the job twice as I learned a few things, so hopefully this helps someone else avoid all of that.

Is Tesla potentially putting the public at risk with it’s cost-cutting strategy?

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I’ve made no attempt to hide the fact that I’m not a fan of Tesla. It was never about the technology, but rather their business practices and the way they treat their customers. However, that may be about to change with what I would consider to be a penny wise, but pound foolish decision to remove radar and ultrasonic sensors from it’s vehicles.

In a report from Electrek, Tesla is basically saying that they’re going all-in on computer vision and dropping other sensors with the laughable justification that it’s how humans navigate. Considering the potential consequences, perhaps laughable isn’t the right word.

One of the features that impressed me the most about Tesla’s early self-driving feature was the integration of radar data. A perfect example of this can be found in this 2016 video of a Tesla detecting a vehicle several cars ahead that was moving slowly/braking and was able to avoid an accident. You can’t see the vehicle ahead as it’s completely obscured, but the Tesla radar could. Can a Tesla camera system do the same? Maybe, but I’m not sure I’d want to trust an autopilot system without radar. (or some other form of beyond visual spectrum object detection)

Tesla’s track record with self-driving cars hasn’t exactly been fool-proof either. (even with the additional sensors) I’ve been in Teslas that have had difficulty in daylight with the painted lines of the road. There have also been numerous incidents reported where autopilot didn’t see a crossing/oncoming vehicle resulting in fatalities. Beta testing software features is fine for the consumer smartphone and computer industries, but it shouldn’t be something that happens in cars on public roads with safety-critical systems.

Tesla does state in their announcement that “at this time, [they] do not plan to remove the functionality of ultrasonic sensors in [their] existing fleet.” Hopefully the same is true for the radar sensors as well. This appears to be targeted at new production models only with models 3 and Y, and later the S and X.

This Reuters article from early June explains some of the details of why a camera-only system could be less safe than one with additional radar sensors. Tesla may think they’re saving (making) money removing the sensors and making development easier for themselves, but not tackling the more difficult problem of integrating different sensors leaves gaps that may put people’s lives at risk.

Update 12/2022: Drivers of new vision only Tesla models already running into problems, some features not yet available

Update 12/16/2022: Tesla appears to be reversing course and bringing radar back based on FCC filing. Elektrek quoted the same tesla filing indicating Tesla would be marketing a new HD radar in mid-January of 2023. This is good news for potential new buyers and potentially for improvements in FSD, but what about those who bought the stripped down versions? If I were one of those customers, I wouldn’t be too happy.

Car Updates 2022

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The past year has been an interesting ride for sure. While I didn’t get to race at all, I did manage to attend a few track days at the beginning of the year, even though the MINI needed a new clutch. In my last (car-related) post I bid farewell to our old E39, but I didn’t mention what had replaced it.

Originally I was trying to find another 5-series as I had really enjoyed the comfort of the E39. (it’s still the most comfortable car I’ve ever driven) I looked around at used F10 and F90 550 and M5 models, but was warned about the engines by my mechanic.

I sat down and thought about what it was that I really wanted and it came down to a few things: sporty, manual transmission, (no flappy paddles) decent horsepower and comfortable.

I looked at a lot of cars online for a little over a year, but eventually I started to settle on either BMW or Porsche. On the Porsche side, I’ve always loved the Cayman. Having never driven a mid-engine sports car this was definitely an interesting choice. However after scouring the internet for months, I realized that Porsches hold their value far too well. I would need to settle for a significantly older model to afford one and it would also be significantly less practical as a 2-seater.

Swinging back to the BMW side, I decided that if I was going this way, I wanted a M car. One day I stumbled on a listing for a 2016 M4 in Yas Marina blue with decent miles and seemingly in great condition. As a number of cars had already slipped through my fingers, I didn’t get my hopes up, but to my surprise the car was still available the following Saturday. I set an appointment with the dealer that was about a 3hr drive away, cleaned out the E39 and drove up with the family.

Everything went well, the car checked out (I even brought my BMW scan tools to verify) and I ended up trading the E39 for it that day.

My F82 M4

Over the last year, I’ve really enjoyed having this as my daily driver. It’s admittedly a lot of car for that role and I’m sure some would wonder why I’d choose it. However, I’ve always thought that cars were meant to be driven, not to be collectors items. This M4 is about as close to my goal as I could achieve. It’s probably the last generation of fully manual gasoline-powered M model that BMW will produce and far more attractive than the current model. I want to enjoy this last era of full manual, dinosaur-burning muscle before they’re all gone and we’re relegated to driving (or being driven by) a computer on wheels.