Nissan Frontier

[RedSN]

OEM Nissan (Aisin) on the left, aftermarket MotoRad on the right.

Small differences, but the most obvious is the baffle on the side of the OEM. I’m not sure what it does, but it’s clearly more complicated than any t-stat I’ve ever seen. The thermostat housing is fed by the lower rad hose and flows into the “water inlet” where there seems to be a complicated system of channels and pipes that feed the water pump among many other things. So that baffle is directing coolant to somewhere it needs to go that the aftermarket t-stat does not.

Baffling (no pun intended) was that with the MotoRad the truck behaved like it had a bad clutch fan. It would stay normal on the highway, but oddly the A/C electric fan would kick in. In the city with prolonged stops at lights idling, the temp would start creeping up.

So far, after a test drive to the beer store, the temp is sitting rock steady, and the A/C fan isn’t kicking in. Will see how the trip to London tomorrow goes on the highway.

Lesson learned: OEM Nissan parts for anything engine related.

[Scrape]

Quite different. Looks like the springs are different as well.

[ZR]

We make a point of using OE thermostats the last few years, cuts down on comebacks just like yours would have been.

[LX89]

I've had a MotoRad 195* high flow thermostat in my Mustang for a long time,probably close to 20 years,not exactly sure.

Back then they were well made with thicker metal,large opening.
At some point they cheaped out and used thinner metal and a smaller opening.

[LX89]

When the original thermostat crapped out in my fathers 97 Accord 2.2,I went to the parts store and the guy looked it up and gave me a 195* Stant t-stat which I assumed was correct.

It wasn't.
With the 195* Stant the engine ran hotter and when you shut the engine off one of the fans would run for over a minute then turn off.
I looked it up and a 180* was the correct t-stat for that car.
Put in a 180* Stant and that solved the problem and the car still throws off a ton of heat from the heater.