NA Miata Radiator Replacement

One of the telltale signs that a NA Miata Radiator is in need of replacement is the color of the plastic at the top. As the plastic ages, it will fade in color from black to brown. When the plastic ages and changes color, it tends to get very brittle and is prone to developing cracks. Replacing the radiator is an easy preventative maintenance job to prevent getting stranded.

Estimated Mechanic Cost (Parts + Labor)	Parts Cost	DIY Savings
$850	$125	$725

Tools Required:

• floor jack
• jack stands
• drain pan
• 10, 12, 14 mm sockets and ratchet
• philips head screwdriver
• hose clamp pliers

Parts Required:

• radiator
• 1 gallon coolant

Instructions:

1. Jack up the car and secure it safely on jack stands.
2. Locate the drain plug for the radiator. You do not need to remove the belly pan, there is a cutout to access the plug. Using a Philips head screwdriver, undo the drain plug. Make sure you have a catch pan for the coolant. Once you have ensured that coolant is being caught by the pan, you can undo the radiator cap for faster draining.
3. Remove the plastic air intake tube by loosening or removing all of the hose clamps attached to it. There are 2 large hose clamps to loosen with a screwdriver and pop off the throttle body and air intake. Then there is one small hose clamp to pop the breather hose off of the intake tube. Lastly, there is a medium-sized hose clamp on the left side of the intake tube that goes towards the throttle body.
4. You can now access your radiator fans. Start by disconnecting the electrical connector on each fan.
5. Remove the 8 10mm bolts holding in the radiator fans. There are 4 bolts on each fan, 2 at the top, and 2 at the bottom. It is extremely common for these bolts to be rusty and corroded, so it is recommended to have new hardware on hand.
6. Disconnect the lower radiator hose from the radiator. Depending on how the hose clamp is oriented here, you may need to remove the belly pan for better access. Note that some more coolant may drain out here, so be prepared with your drain pan.
7. Disconnect the upper radiator hose from the radiator.
8. Remove the 2 12mm mounting bolts on either side of the radiator.
9. The radiator can now be wiggled out of the car. Grab each side of the radiator and slide it upwards.
10. Depending on whether or not your new radiator came with them, you may need to transfer the lower mounting rubber grommets. They are secured to the radiator with a small C-clip. Simply pry out the clip using a screwdriver or pick, then push the grommet out of the old radiator. Then push the grommet into the new radiator and put the C-clip back on.

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