Hey, aren’t we done yet?
I don’t know if cars are ever done, but tomorrow we return this little gem back to the owner. During all the service and care and feeding the owner was kept up to date on what was done and what was found. He was happy to get everything done completely and done right. Believe it or not, that can be a rare attitude with a car owner.
We recommended replacing the timing belt even though the mileage didn’t indicate a need. The time certainly did. There was over ten years on the original timing belt.
Even though we had taken much of the gear off the engine to replace the heater hoses and the drive belts we had to take it all off again to get to the timing belt. Keeping that in mind we also opted to replace the water pump. Some times the intake throat to the water pump can get clogged up with mineral deposits. It often happens if you don’t use distilled water to mix with the antifreeze concentrate.
Off came the freshly black wrinkle painted valve cover. Out came the antifreeze that was put in when the hoses were changed out. That proved to be a good thing because the drain pan showed that a lot of loose deposits were also drained out with the antifreeze. The spark plugs were removed to make it easy to turn the engine over as the cams and crank shaft would need to be lined up for the new timing belt to be installed.
To get the water pump out requires the cam gears to be removed as well as an access plate behind them along with the thermostat housing. The water pump turned out to look like it was is pretty good condition. It was replaced with the new one anyway.
Then the new timing belt was installed. We chose a Gates Racing version for its durability. Since the owner doesn’t put a lot of miles on this car durability is just as important as if it were a high mileage track car. We also replaced the idler and tensioner pulleys. The idler pulley bearings were worn in any case. With the cams and crank lined up, the tension set, everything was snugged down and the parts and pieces were put back on.
The moment of truth when doing a timing belt is always starting the car up. This time it fired right up and purred like it should. One way of confirming that timing is correct is to check with a vacuum gauge, but it was clear that this car was in perfect time. We later took it out for a road test and the power came in beautifully.
There were a couple of more things to get done. The first Miatas came with a working oil pressure gauge, but in 1995 the factory decided to replace it with something that looked like a gauge, but was really an idiot light in disguise. It had a pointer and marks, but was connected to an oil pressure switch, not an oil pressure sending unit. That meant that what ever pressure the sending unit was set to that would be enough to tell the “gauge” to move the pointer to the center of the gauge. Unfortunately an oil pressure switch is likely set at 5 or 10 pounds of pressure so you might not know until it is too late that you have a problem.
We scouted out eBay and found a pre-1995 gauge and sending unit for a pretty good price. They showed up and we got to work. There were several screws between the instrument panel and us to be removed and then we could pop off the instrument shroud and unscrew the cluster. We pried off the clear face and then removed the fake gauge, replacing it with a real one. The cluster went back in and we put the dash back together. Then got under the car and removed the oil temperature switch and replaced it with a proper sending unit.
That last sentence makes it sound easy, but if you check any of the Mazda Miata forums on this switch you’ll find that it is quite a challenge.
Everything turned out just fine. We turned on the engine and were greeted with an oil pressure gauge that acted like a real one and nary an oil leak from the replacement sending unit.
Next was the installation of the aero package the owner had removed from a donor car a few years ago. It consisted of two pieces that fit on the back of the car ( a short piece completed things on the right side of the tail pipe) and a front air dam of sorts for the front. The front piece had ducts for brake cooling as well.
It took a while to match up the parts, drill holes, and attach the bolts and nuts. We ran all the old hardware through a tap and die to make sure the threads were nice and clean saving us a lot of anguish. A couple of bolts on the car itself were rusted solid so we cut them off and replaced them.
A picture is worth a lot more than words so here it is. I hope the owner enjoys the results as much as you do.