Thermostat direction
 

Just double checking my work. Car won't come up to operating temp now that it's cold out. Even after 40 mins on the interstate with heat off.

So which way does the thermostat clock inside its housing? Little thermo towards the front of the car or towards the rear?

I went ahead and got a new OE thermo today. When I get home, I'll install it, then test the old one in a pot of water on the stove.

Thx

Themo end that needs to get hot to open would go on the side hot watter side. If you put it backwards it would cause it to overheat before opening, but then it would work sorta. Do you have an oversize radiator?

Yes, Griffen aluminum radiator.

What temps were you seeing. I was seeing 140°F the other morning at about 45-50° out. I chalked it up to system changes I had made the day before.

Don't know, didn't datalog or anything. But I could tell that enrichments were active by watching my XD16 (digital readout wideband gauge). Temps were definately not hitting 175° because fuel overrun never kicked in. Tail pipe is black and sooty.

I'll charge up the laptop tonight and log tomorrow I suppose.

Man its still 70* out over here in CA, we still get to drive with our tops down/off.

If you have returned the heater core to the top of the radiator, this will happen regardless of the thermostat in cool weather.

Cooling system is stock other than Griffen radiator and NB lower rad hose. Coolant routing is all stock. Thermostat was replaced a few months ago with the radiator.

Then I would suspect the thermostat. Arrow on t/stat should be up on a 1.8 and toward the engine on a 1.6


But it really doesn't mean shit.

really? hmm, that might be the problem...:dunno:

It was my understanding that the "sub thermostat" went towards the front and the "main thermostat" went towards the rear.

In Mazda Parts Catalog, it shows the arrow facing the engine, which has the main and sub thermostats side by side.

In Mazda's Workshop Manual, it shows the sub facing the engine and the main facing front.

I wouldn't worry about the positioning. The hot water hits everything. Except if in one position it can jam against the housing.

I removed the couple months old mazda OE thermostat and compared it to the new, Mazda OE thermostat. They are completely different designs. The old design opened much more than the new one when put in a pot of hot water.

I put the new thermo in the car, and the car maintained 196°F this morning in 45° ambient. I am going to modifythe old thermo to open earlier and wider, and save it for summer use.