It has been over a year since my last update, and a lot has happened since then.
After my last update, the first change I made was in getting a new handbrake and shift knob from kooglewerks, and after installing it I almost immediately decided that I needed the nardi wheel to match... because of course I did. A bit after installing the wheel, I drove out to Bimmerfest West and along the way I found a group of other o2s all driving together. I figured that since I thought I was already late, I would rather be late in a group or end up where ever they were going than pull in to the meet late on my own. They turned out to be a great group of guys who go to meets and C&C events regularly somewhat local to me, and I have been going to events with them ever since.
After the Bimmerfest West and a few more meets with that same group, I found that I was having a bit of a cold start issue and decided that I would rather leave anything having to do with the Tii injection tuning to someone who knows what they are doing a bit more than I do, so I brought the car up to Le Tran from 2002GarageWerks to take a look at it. Unfortunately there ended up being more than just a cold start issue. When I brought the car around, we saw from the plugs that it was running lean which was the first sign that there was more to the issue. After I left, Le sent me the compression numbers both before and after valve adjustment. Additionally, the valves were adjusted far too tight and there was excessive wear on the cam. While it was over there, Le put in a new coil and 123 Bluetooth distributor.
After I got the car back, it was running worse than It was even before I dropped it off. I began the process of taking off the head to replace the worn down parts and hope to fix the compression in the process. During disassembly I found that the plug wire to cylinder 3 was broken, which obviously didn't make anything better.
While taking everything apart, I made sure to label all of the vacuum lines, fuel lines, and wires to help make sure I put it all back together correctly.
After I took it all apart, a good friend who I met back at Bimmerfest West got me all of the head parts I needed and in return I gave him the enki 15 inch wheels I was using at the time and about $200, saving me a bit of cash for everything else that needed to be done. I then drove the head out to Bob's Automotive Machine Shop to have it rebuilt with all of the new parts. Here the disassembly process is shown:
here are the new parts compared to the old:
After everything was taken apart, they began the cleaning and rebuilding process:
The rebuild included a pressure test, resurfacing, valve guide install (late type), and valve job.
Once I got it back, I re tapped all of the threads on the block for mounting the head, and re tapped the head as well prior to installing the studs.
I was finally able to reinstall the head and put everything back together as well as do timing.
Once it was all back together, I refilled the coolant and oil, and primed the head my cranking the motor with no spark to get it all oiled up as you can see in the first video. Then the videos after that are the first start and first time at idle.
cranking w no spark.mp4
After the motor seemed to be happy and was able to sit at idle for a while without any issues, I decided to take it down the street for a test drive, which didn't end up working out too well. When driving downhill it seemed to be doing fine aside from some popping on deceleration so I went to turn around and bring it back up to my garage, and as soon as I started back up the hill my temperature suddenly shot up and I had a major loss of power, so I was barely to get it back inside as it started billowing steam out from under the hood.
test drive overheat.mp4
Additionally the exhaust manifold was glowing by the time I got it inside.
Based on all of this, I suspected that this was an AFR issue as I said in the video. That turned out to be exactly what the issue was, and what I suspect caused the sudden jump in temperature was the cold start fuel enrichment turning off after it got to operating temp, which was the only thing keeping the car at a somewhat normal AFR. After it turned off, the car leaned out due to several vacuum leaks which I later tracked down, resulting in it running so hot and being so low on power.
To fix the issue, I smoke tested everything and found and patched several leaks. After they were all patched, I re adjusted the AFR and reset the ignition timing, which totally fixed the issue and the car has ran happy since then..... until the differential blew less than a month later. FUN!
What had happened was I heard a loud bang from somewhere in the drive line while taking a fun corner on the way home but was not sure where it was exactly in the drive train. As I limped it the rest of the way home, I noticed a consistent noise that sounded like a mechanical thud based on wheel speed. At first I was not sure what the issue was, and I had assumed that it couldn't be the differential since it didn't lock up and I was able to limp the car back home. After having it towed back to my parents shop, I swapped the guibo and whole driveshaft because I had assumed that a U joint or the center bearing could have been the culprit. Thankfully, I had a spare driveshaft so this attempt at solving the issue didn't cost me more than a new guibo and hardware.
Obviously this didnt solve anything, so I put the car on a lift, jacked up the rear wheels, and had someone get inside and drive it in the air to try to find the issue. Immediately we could tell something was wrong in the diff when only one side spun, which I would not find too odd from an open differential like this, but its not like more load was being placed on that side than the other so there was no reason both sides shouldn't have spun.
after using a mechanics stethoscope on the diff, it was obvious that something internally was being ground up. here is what some of the drained oil looked like (keep in mind I changed it about 2 months prior)
Thankfully I also had a spare differential from the same car as the spare driveshaft (new on the left, old on the right) I also noticed a few differences between the two, the main one being that the old one had some extra holes drilled in the output, didn't have the same structural ribs on the top, and had different markings on the bottom.
I cleaned up some of the hardware in a sonic bath, and put everything back together
One of the lessons this car has taught me is that right when you think you are done, you will get a new to do list one way or another. Another lesson it has just taught me this past week is that if you see a great opportunity, don't hesitate to take it. Both of which came in the form of this Facebook ad another friend from that same group had sent me.
A freshly rebuild 245 with less than 500 miles is worth a whole lot more than that. After talking to the seller, I learned that he had just put it in his 2002 but after felt like he wanted more power for the straights of the canyon he lives in, and is planning on doing an S2000 swap. He wanted to sell it locally and see it go to someones project nearby. Some prospective buyers from the east coast had told him how much it was worth after he refused to ship it, but he had told me that that was not nearly how much he had bought it for and that he isn't doing this for profit, and would feel wrong selling it for so much more than he had paid. Even more fortunately for me, he was able to get me the rest of the 5 speed swap components, saving me enough cash to keep the car going. As of now, I have the transmission, a brand new clutch, flywheel, clutch slave cylinder, shortened shift linkage/ mounting plate, and hardware. Next week I will be picking up the shortened drive shaft, speedometer cable, clutch line, and rear cross member. I hope to install everything at the start of winter break when I will have all the time and parts needed to put everything together.