i ran a search, but evidently i suck. . . cause im pretty sure this has been covered.

anyways, ive been noticing my oil temps NOT reaching 180F while driving around. i dont recall ever having this problem until lately (last couple months). it only moves up to 180F if i let it sit and idle for a while. then, while driving, it can/will stick at around 140F.

i always thought there was a bypass valve in the stock system. am i wrong on this? is this normal operation, and im just a wierdo?

 

Are you using a stock oil cooling setup or an aftermarket setup?

 

stock. non r1/r2

 

If you have fairly cold weather (seeing 30's or maybe lower) and you are running a heavy weight oil, I could see that happening.

 

well, i kinda thought that may have been the deal, but its been in the 70's just about all this week. i run 10w-30. i wonder if i have the sensor in a bad spot. its located in the banjo bolt for the oil cooler line located at the top of the engine (under the oil filter pedestal). i cant remember if thats the return line or not.

 

That's where my oil temp sender is, and my oil temps are usually around the current water temp. They'll creep up when I'm sitting at a light, but drop VERY fast when I get moving again.

Dale

 

According to the Mazda shop manual, the stock oil thermostat opens at 140 degrees (F), which would correlate your observations.

 

Personally, I think the sensor isn't in the full oil stream to get temps that low with a single stock cooler.

 

If it's mounted in the banjo bolt, it can't help but be in the oil stream.