Recently, I have been noticing my coolant and oil temperatures rising faster then "normal" during elevated RPM operation. Holding gears (IE 3rd/4th at 5-6K+)

I have gauges, coolant sensor next to ECU sensor and oil sensor in banjo below A/C compressor. Also, use and App for direct ECM readings.

Previous "normal" would have stable coolant/oil 180/190 while cruising 4k RPM and coolant/oil 200/220 while pushing over 7K RPM (for the last 10K miles). Current observations (last 200 miles) have coolant/oil climbing to and thru 190/210 while accelerating thru 6K in 6th on highway. All temps return to normal levels during cruise state.

This morning it was 45 degree and at 5K in 6th (yes, I was speeding) on highway was running coolant at 180 and oil at 215.

Not worried about if the engine is going or gone. It was planned to leave the day I bought the car (know wear item). What I am concerned about is the possible causes since this is a new phenomenon that has my curiosity.

Currently, stock engine 47K miles compression on the low line (mid-pipe, D585 coils,CAI and Shon) new FL-22 and OEM thermostat as 2,500 miles ago. Radiator is stock and in like new condition and system holds 16 PSI and Cap holds 12 PSI for 12 hours straight (Overnight tested). Also, did the block test (blue fluid bubble test) for combustion gases in the coolant system with negative results.

There is no blockages at the radiator and the foam/under tray is in place correctly.

Just need enlightenment to the thermodynamics that is causing this issue to develop.

 

I’m confused about what the perceived issue is. Try using less text and be specific.

 

can always count on you to be you! Love your knowledge

Cruising oil temp at 4K RPM has gone from 190 to 215+

Question, What is the main contributor to oil temp? What could be a cause of sudden temp rise even at lower ambient air temp?

All the text was the back information that always gets asked or thrown out as causes by the shade tree pros.

 

Possible one of the oil thermostats in one of the oil coolers is stuck closed...

Other than that can't think of anything easy that would cause a sudden increase in oil temps.

 

It was designed to run at 220*F by Mazda via the oil cooler thermostats. One might have been stuck leading to the lower reading or any number of possibilities as to why it was different.

You can buy and replace OE with aftermarket 180*F thermostats if you want.

https://rotaryperformance.com/produc...ler-thermostat

which I’m assuming you’re not interested in reworking all the lines to use an external aftermarket t-stat and removing/blocking the OE ones, there are threads on that and the differences

 

Thank you for your help guys. Addressing the Oil/Coolant cooling capacity is scheduled for this winter with the new engine.

 

If you just rework the lines, remove and block the OE cooler t-stats and use a good external t-stat you’ll find that the OE coolers are more than sufficient. For most people just swapping out the oil cooler t-stats will be fine.

 

Understood, Always figures to just lower the thermostat for the oil and then open airflow. Still wondering about exit airflow and where to send it for high speed runs. Fender venting with louvers possible/