Suspension Noise and Caster Fixes on the S2000

Once the S2000 starts to generate heat around the suspension, it started to having this clunking knocking sound at low speed like driving around a parking lot. It wouldn't do this at high speed (or at least I couldn't hear it) and it didn't seem to affect performance but it was really annoying me. I resolved to fix this. First, the rear lower control arm spherical bushing had to go. It had started to wear and had a mm or so of play in it causing that knocking sound. This bushing doesn't really need to be a spherical so I opted to have it replaced with Hardrace hard rubber bushings instead. This is still going to provide good feel while improving NVH.

Hardrace hard rubber rear lower control arm bushings

worn out sphericals

The second fix was to allow the springs to rotate more freely as the suspension compressed and unloaded. This is achived by adding Swift thrust sheets between the spring and the perches so that it can glide freely and not bind.

Swift thrust sheets

Finally, I wanted to fix the relatively low caster we were measuring on the car ever since I went with sphericals. S2000s should easily achieve over 5 degrees of caster and I was maxing out at around 3.4. The front control arms were removed and the spherical adjusted over to make the control arm sit at the appropriate angle and now over 5 degrees of caster is easily achievable. 

Control arm spherical adjusted

New alignment looking great

Car drives amazing again with no more clunking sounds in the rear at low speed.

Maintenance Update:

Mileage: 67,150

- New Hardrace hard rubber rear lower control arm bushing (part no 7423)

- Swift thrust sheets on rear coilovers

- Reposition front control arm spherical bushings

- New alignment

Fixing oil leaks and replacing fuel pump on the 944

I was continuing to have oil leaks from both the front and rear main seals on the 944 so I took it to Lee Autoworks to have this fixed once and for all. He found the crankshaft to having about 1.4mm of play which is well outside of tolerance which should be less than 0.4mm so we agreed to pull the engine out and have a closer look. 

Engine out inspection on the 944

The thrust bearing had excessive play and since the engine was opened up anyway, I had him check everything else out. There was a tiny bit of wear in the conn rod bearings and main bearings. Nothing to be super concerned about but I opted to have it all replaced along with all the seals since I don't want to have to do this all over again.

Fresh parts are here

I also took this opportunity to have the fuel pump, fuel filter, in tank strainer and hoses replaced so that I have peace of mind. I had no record of it ever being replaced and given the car is 33 years old I didn't want to have to second guess the fuel system so it seemed like a prudent thing to do. It did seem like it was replaced at some point so perhaps this was unnecessary but at least I know now exactly when it was done and it'll be happy for years to come. The crankshaft and camshaft position sensors also tend to go bad on these cars and given its age, I also had both replaced with new ones. 

He also go to the bottom of why the car kept stalling or having a no start condition. The connector for the mass airflow sensor was loose causing it to sporadically disconnect. He tightened up the connectors so it would have a firm electrical connection and now it starts like a champ every time. 

Engine back in and fully functional

People say these engines are some of the smoothest 4-cylinders ever made and while it was fairly smooth before now I really understand what they mean. At any RPM the engine is hyper-smooth with good power delivery. Such a joy to drive!

Maintenance Update:

Mileage: 97,356

- 6 quarts Valvoline 20W-50 VR1

- Mahle OC142 oil filter

- New OEM fuel filter

- New OEM fuel pump

- New OEM in-tank fuel strainer

- New OEM fuel hoses to fuel pump

- New OEM main bearings

- New OEM thrust bearings

- New OEM connecting rod bearings

- New OEM oil pickup tube

- New OEM crankshaft  position sensor

- New OEM camshaft position sensor

- Fresh antifreeze

- New engine seals

New CV boots for the Cayman

Last year while I was changing oil I noticed a bit of greased around the brake sensor and realized it was coming from the CV boots (both sides). I don't think it was turn but rather leaking by the clamps. Either way, they were getting old and after 17 years, I think the rubber had served its purpose. I ordered a new CV boot kit from Suncoast and finally today went over to Lee's Autowerks so he could make quick work out of it. While it was there also had him change the transmission fluid since the OS Giken diff was started to get a bit whiny. 

Leaky CV boot

Fresh OEM CV boots

Maintenance Update:

Mileage: 52,887

- New OEM CV boots on both axles + new clamps and grease

- 3 quarts Motul 75W140 Gear Oil

New Battery for Scarlett

Well for a few weeks now my CTek battery tender would keep showing the red light when trying to charge the battery on Scarlett. I thought maybe it was just the charger being bad but sure enough, the battery was down to 10V and was not holding charge. Very strange since it was only about 3 years old and I haven't put that many miles on the car. Either way, replaced it with a new battery and all is fine again.

Maintenance Update:

Mileage: 173,372

- New Duralast Platinum H6 / Group 48 AGM battery

Flooded Cylinder 1

I was getting ready for my next track day when the car wouldn't crank. At first I thought it was just a bad battery so I swapped in my spare battery and same thing. It would try to turn but stop like it was stuck. I was looking everywhere for anything broken and realized I was smelling fuel but saw no fuel leak so I started pulling the plugs out and found this. The spark plug in cylinder 1 was very dark and went from fuel and I could smell a strong scent of fuel coming out of the cylinder. I checked the other 3 cylinders and they looked just fine. 

I then took a wrench to manually turn the crank and fuel started com up through the spark plug tube. For some reason the cylinder was flooded with fuel. I soaked up all the fuel as it came up as I kept manually cranking. Once I felt it had cleared and let it dry overnight, I changed the oil and put in a fresh set of spark plugs and tried to crank it and it started for a few seconds then died again. Took the spark plug out and it was wet with fuel yet again. I cleared it out again and just double checked the compression to make sure it was still and and it was still above 240.

So shutting off my fuel pump and cranking allowed the engine to crank but as soon as I applied fuel it would flood. Either I wasn't getting spark or I had a leaky injector. I tested for spark and sure enough I had spark so it wasn't that. Before checking the injector, SJF said to get a noid light and see if I was even getting proper pulses to it. This is when the literal lightbulb turned on. The noid light should be off normally and pulse as the ECU signals the injector to fire. Instead, even with the key just in the on position it was already on causing the injector to just stay open.

Noid light staying on

I then wiggled the wires and the light would flicker on and off. Aha, I had a short somewhere. I stripped back all the harness wrap and the heat shrink wrap around the solder joints. The joints looked good but I'm guessing at some point it poked through the insulation somewhere causing a short so the plan was to apply new insulation. I also thought it'd be a good opportunity to replace the very brittle injector clips that were falling apart with each touch. Perhaps the short was there as well. 

New injector clips

I depinned the clips and slid on some new high quality heat shrink tubing that has adhesive on the inside to prevent it from sliding around. I then put the pins in the new connectors. I wrapped everything in high temp harness wrap, the kind you see on most Euro cars, and then re-tested then noid light. This time it stayed off as expected and no amount of wiggling caused it to flicker. I changed the oil yet again and put in another set of fresh injectors (the previous one I tried was a cheaper variation I could easily get my hands on as a stop gap). It fired up, idled just fine and had perfect air/fuel ratio. It did take a while for the exhaust to stop smoking. All that oil and fuel and had to get burned out but once all that was done she was back to driving like a champ.

Fresh NGK Iridium Laser 7746 plugs

Driving normal again

Maintenance Update:

Mileage: 67,079

- 4 x NGK Irdium Laser 7746 spark plugs

- 5.5 quarts Amsoil 10W-40
- New OEM oil filter

- 4 x new injector clips