Microsquirt Coolant Temp Sensor setting

[Drscottsmith]

As promised did some sleuthing to see what was going on inside the cooling system. Pulled off several lines so I could check flow everywhere. Pulled thermostat (ugh!) and tested it.

Lo and behold - thermostat will not open in boiling water on stove (80C version). Makes perfect sense with the way the different sections of the system were measuring in terms of temp.

New 80C on order and should be good!

Thanks all!

[Tom]

As promised did some sleuthing to see what was going on inside the cooling system. Pulled off several lines so I could check flow everywhere. Pulled thermostat (ugh!) and tested it.

Lo and behold - thermostat will not open in boiling water on stove (80C version). Makes perfect sense with the way the different sections of the system were measuring in terms of temp.

New 80C on order and should be good!

Thanks all!

Excellent. Glad you found the real culprit. And welcome to the club -- removing a 944 thermostat is a rite of passage.

[Drscottsmith]

Yep - first time was easy as engine was on a stand. In car is a bit different!

So reporting back that everything is back to normal, but my aftermarket fans are not pulling enough air.

I am going to remount the factory setup but control the new relays from microsquirt. Right now it will just be fans on/fans off but eventually I hope to have digital pwm control of full variable speeds.

New thread with my next project in the turbo thread.

Thanks all!

[Tom]

Yep - first time was easy as engine was on a stand. In car is a bit different!

So reporting back that everything is back to normal, but my aftermarket fans are not pulling enough air.

I am going to remount the factory setup but control the new relays from microsquirt. Right now it will just be fans on/fans off but eventually I hope to have digital pwm control of full variable speeds.

New thread with my next project in the turbo thread.

Thanks all!

Sorry if this has been asked and answered, but why not just use the factory fans and control system?

[Drscottsmith]

Wiring was shot and one resistor broken. I wanted to use microsquirt canbus + arduino to control a pwm based system with full variability.

Needed to get the car running and driving so right now the fans are just all on or all off. I was going to use aftermarket fans (those are on right now) but they don’t seem to pull enough air.

One of the factory fans is pretty difficult to turn, so l am going to rebuild that then use those with the on/off relay system to at least get enough air in traffic moving.

Eventually I hope to get the pwm controller set up but will use with the factory fans.

[Tom]

Wiring was shot and one resistor broken. I wanted to use microsquirt canbus + arduino to control a pwm based system with full variability.

Needed to get the car running and driving so right now the fans are just all on or all off. I was going to use aftermarket fans (those are on right now) but they don’t seem to pull enough air.

One of the factory fans is pretty difficult to turn, so l am going to rebuild that then use those with the on/off relay system to at least get enough air in traffic moving.

Eventually I hope to get the pwm controller set up but will use with the factory fans.

Porsche did a pretty good job engineering these cars -- more often than not aftermarket upgrades are really downgrades. But just curious, why do you say the aftermarket fans don't pull enough air? If it is still running warm while going more than 10-20mph, that's probably not the fans' fault. If it runs cool on the highway, but the needle creeps up when sitting still, even with the fans on, then yeah that's on the fans...

[Drscottsmith]

Yeah as soon as I start moving the temp comes back to dead center or just below (so abt 90 deg) sitting at a light it goes up probably 3-4 deg. It does not get as high as it did before new thermostat (right under 100deg).

[Tom]

Yeah as soon as I start moving the temp comes back to dead center or just below (so abt 90 deg) sitting at a light it goes up probably 3-4 deg. It does not get as high as it did before new thermostat (right under 100deg).

That doesn't sound terrible, but for reference, my gauge will creep up to just over half way at a stop light, and as soon as the fans kick on (low speed), it drops back all the way to the first hash. I have a lower temp thermostat and thermo-switch, so I wouldn't expect yours to drop that low, but the fans should bring it back down to whatever temp you see on the highway. If your don't, then I'd agree they aren't working as well as the factory fans would. Ducting plays a big role too, and it's hard to beat the factory fan shroud.

[Drscottsmith]

Yeah another reason to go back to the factory fans. I did not want to cut the plastic shroud to adapt the new fans (glad I didn’t).

Right now I don’t have the shape of the factory shroud at all.

I think the factory fans will make a big difference. I do have an 80 degree thermostat now and my fans are set to come on just above the lower tick mark. I’ll get the computer tomorrow and take some official measurements. I cleaned all of the grounds when I replaced my old gear last week so I think my gauges are reading accurate now.

[Drscottsmith]

Just went out for a little tuning drive.

Coolant temp readings stayed around 194-196F moving when running 60-70mph. Stopped at a light coming back went up to 200. Back to 196 as soon as I started moving again.

There is more movement than I would like in the gauge between 195 and 200, but I think I just need to get used to it -

Thoughts-