Mike's 2018 CX-9 Signature

[sm1ke]

Got everything all sorted out with the engine overheating issue on Friday evening. I drained the coolant, then replaced the thermostat and engine coolant temperature (ECT) sensor with brand new Mazda OEM parts. Refilled with the recommended 55/45 Mazda OEM coolant. Mileage on the car is almost at 139k kms.

Something to note - the turbo intake clamp was loose. When removing the turbo intake pipe to gain access to the thermostat, I was able to simply pull the pipe towards the fender to remove it. I did not have any performance issues before this, it's just something to note. The pipe is secured with a couple of screws, along with at least one hose connection to ensure that it doesn't just fall off if the clamp is loose.

The hardest part of this job was retightening the loose clamp where the turbo intake pipe meets the turbo. Because of the location, it's impossible to get a normal ratchet in there, and the bolt is right between a couple of hoses, so you also have to use a deep socket or an extension (see pic below). On top of that, because the nut I needed to tighten was so loose, I had to also hold the extension so that it would actually ratchet instead of just loosen the bolt again. I had to stand on a step stool at the front of the car, reach over the engine bay to the back, then thread a swivel-head ratchet with a 2" extension between a couple of hoses and the heat shielding, and hold the extension in place while also supporting my weight. I didn't even realize that 1/4" drive flexible socket extensions were available - one of those probably would have made this part of the job a whole lot easier and faster, haha.

Here are a few pics of the process.

Air intake out.

Battery out. The tray is held in place with three 12mm bolts.

Turbo intake pipe removal. The upper nut is a 10mm, the lower nut is a 12mm. The transmission vent line is just clipped into it's receiver. It comes out pretty easily.

The workshop manual says to disconnect this tube to remove the turbo intake pipe completely. I didn't have a replacement clamp on hand so I left it connected and just moved the pipe out of the way.

Turbo intake pipe out of the way.

Loosen this clamp (7mm) to disconnect the plastic pipe, giving access to the thermostat.

View from the driver's side fender.

Thermostat cover off. I believe the bolts are 10mm or 12mm.

Old thermostat on the left, new on the right.

New thermostat installed.

 

[sm1ke]

Location of the ECT sensor. The thermostat housing is just to the left. Unclip the ECT sensor and the connector just above it to make room for your 19mm deep socket and ratchet. A note on these connectors - they're "squeeze and pull" connectors, but you want to squeeze closer to the "middle" of the connector, instead of near the end, where the wires feed in.

Old sensor on the left, new on the right.

New sensor installed with washer.

Tightening up the turbo intake pipe clamps. In this pic, I actually had the ratchet on the wrong clamp. It's actually an inch or two to the left, on the other side of the tube.

All in all, this job was about 2.5 hours from start to finish. Could have cut it down to 1.5 hours if I had a replacement clamp for the tube on the TIP above. Cost me about $150 CDN for parts ($35 thermostat, $60 sensor) and fluids ($60). Oh and one more note: the workshop manual states that you need a special $20-30 socket to remove the ECT sensor. You don't. A deep 19mm or 3/4" socket works perfectly, as shown below.

The battery tray modification also worked out perfectly.

 

[N7turbo]

The hardest part of this job was retightening the loose clamp where the turbo intake pipe meets the turbo. Because of the location, it's impossible to get a normal ratchet in there, and the bolt is right between a couple of hoses, so you also have to use a deep socket or an extension (see pic below). On top of that, because the nut I needed to tighten was so loose, I had to also hold the extension so that it would actually ratchet instead of just loosen the bolt again. I had to stand on a step stool at the front of the car, reach over the engine bay to the back, then thread a swivel-head ratchet with a 2" extension between a couple of hoses and the heat shielding, and hold the extension in place while also supporting my weight.

Some/most people won't be able to do this, but I did it as part of the Corksport Turbo Inlet Pipe install. It involved the air box and the battery removed from the car and me sitting in the engine bay where the air box was. Then I could get both arms in there, one under and one over the engine to snug that thing on. The clamp was simple, though. I just oriented the clamp so the bolt could be tightened from above like any other.