How to change Timing Belt and Water Pump on a Mazda Miata
August 25, 2004
Make sure you have an assistant readily available for when you put the belt back on. It really helps a lot, trust me. If you don't have a helper, you can always use my little trick, which I will show you later...
1. Setup
This is how nice my engine looked before I changed the timing belt...
2. Drain coolant and remove radiator
You're going to have to do this before you disconnect any water hoses, so you might as well do it now. Put something under the car to catch the coolant, then unscrew the drain plug on the bottom of the radiator with a Phillips screwdriver
You only need to remove about 4 fasteners in order to remove the radiator. The fastener being removed in this picture is not one of those 4. The fasteners you need to remove are out of sight, perpendicular to the radiator. Once you remove these the radiator should slide right out.
Here is another picture of how not to do it. Note the mangled screw and plastic. I'm sometimes dumb AND violent all at once!
3. Remove Accessory Belts and Pulleys
There are 2 accessory belts on the Miata. One is used to drive the power steering pump and AC compressor, the other drives the water pump and alternator. In the picture above, you can see a little bit of the pulley furthest to the left. This is the alternator pulley. The top one on the right is the power steering pump.
The belt driving the Power Steering is removed here. This is done relatively easily by adjusting the belt tensioner screw found on the power steering pump (the screw with the highest altitude in the picture above). Loosening the belt by turning the screw counterclockwise should give you enough clearance to remove the belt from the pulleys. Since the movement of the screw does not force the pump to move, you may need to persuade it with a gentle push or blow with a BFH.
This is the belt that drives the alternator and the water pump.
The top pulley here is the water pump pulley. The easiest way to get the belt on and off was to remove this pulley by unscrewing the 3 bolts. The proper way to do this is to loosen the tension on the belt by screwing with the tensioner screw on the alternator until you can slip the belt off of the pulleys. I tried to do that but quickly learned that my way is way better.
4. Remove Valve Cover
This appears to be wicked easy, since all you have to do is remove a bunch of screws on top of the valve cover. You will discover that it is a real PITA when it comes to removing the 2 bolts on the side of the valve cover facing the firewall. I really despise the location of those bolts....
