I always sort of assumed that under average driving load, even around the city the operating temp would probably be under 200*F. Is this something I should worry about? The stock temp gauge seems to sit right at 12 o'clock (which, to my understanding, is normal even at 215*).

I see no reason to doubt the temperature reading as I'm just using the stock MSPNP settings, except for the addition of the hi-res firmware. I haven't seen the temp go over 217*, but I'm not sure what's reasonable.

If this is "hot" then should I start looking for basic cooling system issues? Do a coolant flush and test the thermostat and stuff like that?

 

temps peg at 215-217 because that's the max MS will output to your laptop.


certain you didnt screw up your temperature values when you reflashed it?

 

well IIRC it was reading that high before I reflashed it as well (with the factory firmware). Can you confirm that 215 is in fact "too hot"?

I figure the next thing is for me to do the meat thermometer thing and see if it agrees w/ the MS. Should I expect the coolant in the radiator to be pretty much the same temp as the sensor?

 

215 is not too hot. However, your clt gauge in MT showing 215 could mean your temps are 230 or 250 and that is too hot. I wouldn't suggest having the radiator cap off when your CLT gauge is reading 215.

Is your fan coming on? Do you have fan #2 set to come on also? The additional cooling from that may be a good idea.

 

whaaat? MS wont show you higher temps? broken.

 

yes it's true. the temp gauge is limited to 215 F because the limits of the software and someone thought it was necessary to be able to go down to -40. It is possible to modify the inc files I believe so the range start and end higher

 

yep, search what the water cooled guys have done. they basically rescale the resistance curve by hand, so at least the laptop will output the higher temps. -40*F FTL.

 

Maybe it's foolish to trust the stock temperature gauge, but I thought that above 220 or so the stock gauge would start to climb? I have not seen it move past 12 o'clock except 6 months ago when I was legitimately overheating due to a misbehaving fan (now fixed).

The fan does come on, and no I haven't connected the second fan for parallel operation, though I'm seriously considering it now.

What's the best way to confirm that MS is seeing an accurate temperature reading? I know I can remove the CLT sensor and test it in hot/cold water and measure the voltage, but I feel like that doesn't confirm that the whole system (CLT + MS + settings, etc) is working together correctly.

 

fan should be coming on at 207-210*; idle with the rad cap removed and verify this. if it switches on at the indicated temp, I'd assume it's outputting the correct values.

 

FOR 94+: fans should be coming on at 206.7F IF the stock ECU is controlling them. if he is stand alone it's coming on whenever MS thinks it's at the temp that is set for the fans to come on in the msq.

What year car does this guy even have?

If you don't mind pulling the CLT sensor out,

with the sensor still connected to the wiring harness and the key turned to on put the sensor in a cup of ice water. confirm the temp with a thermometer. then put it in very hot water. confirm temp with thermometer. if they don't match what MT shows or at least are very close then you have a problem.

 

Thanks all.

I'm running MSPNP94/95 on a 95. So the MS is controlling the fans. I believe I'm supposed to expect the fan to come on at 175* with the MSPNP base settings.

 

correct. go to more settings and outputs. subtract 40 from the the number in ON-Off limits. that should be the temp it's triggered.


you may want to double check what MS is telling you versus the actual temps...thermometer in the rad filler port should suffice.

 

So I have air scooper (no under tray yet - working on that) stock A/C fan and aftermarket 1200 CFM fan on the car (stock fan died). I just installed a set of gauges (oil temp, pressure, coolant temp), I also have a 16psi rad cap on a koyo. I've been seeing temps in the 190's on a cool day and 208 or higher on a hot day and the gauge starts flashing to warn me and about that time my overflow tank begins bubbling like mad... All that being said I have 2x1500 CFM fans to go on from siliconintakes that you guys have been useing with seemingly good success - just havn't installed yet. Oh and I have an oil cooler... Not to thread jack cause this is really about temps and that's my concern too - do you need a shroud with the 2x12" 1500 cfm fans ? How are you guys not bubbling at 208 or higher ? My overflow literally empties itself to nothing on a 85-90deg day.

FYI I notice better temps at cruise speeds (180-190), higher in traffic (189-200) but can get them down 5-10 deg if I get out from behind a large car so i get good airflow to the nose... Oh and I have dual fan mod.

 

you sure the fans are flowing in the correct direction?

verify that the gauge in MT matches what the actual coolant temp is. don't rely on that cheap gauge you just installed. use a thermometer.

We are not bubbling over at 208 degrees because water doesn't boil till 212F. Not sure what the boiling point is with anti-freeze in the mix. I run my cars 33%coolant/66%water mix in the warmer months

 

I'm running 95% distilled water with water pump lube and coolant. Fans def blowing in the right direction but main fan is a suck advance auto performance fan (1200cfm) - since I needed one that day - I'm gonna throw the good ones in this weekend (do I need to shrould this ****?). How would you put a thermometer in ? Use a meat themo in the overflow tank when it happens ? Prob should run more coolant then, more like 80/20 or your 30/70 mix ? Coolant raises the boiling point no ?

 

shrouding the fans helps. otherwise it can pull air from anywhere instead of through the radiator. we just had a thread concerning this. put the thermometer in the radiator. by the time it reaches the overflow tank it has cooled a bit. put the thermometer in while the car is cool. than watch it while it heats up and compare your readings to the gauge in MT. If it's wrong you are gonna need to reflash your firmware. I can send you what I use on my 9495MSPNP or you can try using sab's files.

 

Cool thanks for the tips.
-B

 

Freezing Point Pure Water:32 F, 50/50 C2H6O2/Water:-35 F, 70/30 C2H6O2/Water:-67 F
Boiling Point Pure Water:212 F, 50/50 C2H6O2/Water:223 F, 70/30 C2H6O2/Water:235 F


I run more water than coolant because water is better at drawing heat out of the engine. So at 33/66 my boiling point is only slightly raised but I never reach it. Also these are temps at atmospheric pressure. Since the system is pressurized(up to your radiator cap pressure) the boiling point is higher. like another 45 degrees.

 

I finally did the thermometer in the radiator test and the temps don't match up. However, I still haven't figured out if this is because the CLT sensor is bad, the Megasquirt has the wrong settings, or my thermostat isn't opening properly.
What I saw was:
I suppose my plan of attack here should be to test my thermostat and the CLT sensor in a pot on the stove. Seems reasonable?

For what it's worth, operating temps are generally just below 215* so that's within MS's range (so I'm probably not at like 240 or something). Also I never see the temp gauge go past 12 o'clock, but I thought for a '94 180* was at about 10-11 o'clock... (making me think the CLT *is* actually reporting >180*).

 

It just dawned on me that I have no idea what thermostat is in my car... it may well be something aftermarket instead of the fancy 2 valve Mazda one. I suppose I'll take a look.

Also my fans do come on at 175 (MT reported temp).