What is the max the water temp should be?

[jscott]

I'm wondering what the max temp should reach in our MSP's...i'm not sure if my water temp gauge is accuratelly reading

 

[CHIQLES]

what is it reading?
my fans come on at 204

 

[jscott]

I had a scan tool hooked up last night on the way home and it reached 230, the dash gauge was right on the middle (normal) range but I thought 230 was high.....this was after sitting and idleing for about 10 mins to get gas and adjust tire pressure....once I got going it dropped to 226 and bounced from there and 228....I blasted the heat the rest of the way home just cause I was worried that might be a little high (i'm a cadillac mechanic and i'm used to the northstar not going past 190)

 

[CHIQLES]

wernt your fans kicking on?
ya id be tripping out also

 

[CHIQLES]

you know i bet this is how these car blow. they over heat and we just blame the turbo setup. If i remember right thats the same issue with the old school jags they all get head problems because the radiator is under size.

 

[jscott]

My fans were on....CHIQLES, thats prolly right, the crappy thing is the gauge (though stock) wasn't reading hot...it was dead nuts middle....I don't even know why I had the tool hooked up and reading data but I'm glad I was....that makes me want a true water temp gauge now....do you know what normal temp is on these? i'm guessing right around 200 though

 

[BOOSTR]

Not certain what the temp is but my gauge has always gone right to just below the exact middle. The stock radiator is great at doing its job. So are the fans. As long as you have a T-stat that is OEM or made in Japan, then I would not worry too much about what the scan tool said. Afterall you have a hot exhaust manifold and turbo hanging on your block. I've blown a head gasket once in my other turbo Mazda. So far with 95K+ miles in this one I have had zero cooling issues.

 

[Carlinator]

Our motors don't blow from overheating, they blow because of the weak-ass internals being stressed beyond their design limits, sometimes on stock boost. It's perfectly normal for modern-ish engines to run at higher temperatures with pressurized systems. Both the antifreeze mix and the cooling system pressure raise the boiling point way above the 212 of plain water, sometimes it gets as high as 260, so temps in the 220-230 range aren't unusual at all. Higher temps mean more efficient combustion, as well as more efficient cooling due to the higher temp differential between the radiator and ambient air.

 

[CHIQLES]

CARLINATOR your are correct modern engines are designed to run hotter and the internal are weak...But this car was designed to be a turbo diesel which run cooler with that fuel. Internals blow due to knock which can be interpid as to much heat..

 

[CHIQLES]

check this out
ive heard head bolts strech car blows up-to much heat
our down pipe is to small causing back pressure adding more heat.
we run a turbo adding more heat
intercooler to small heat not being drawn adequately from air
do you see why i could think the radiator maybe no the right one.
of course not everyone blows becuase of the temp but temp is the enemy

 

[Carlinator]

? I know Mazda took some bits off the euro/JDM turbo diesel models (radiator and IC especially), but the FS-DE was always meant to run gasoline.

 

[CHIQLES]

the only reason im running the 160 stat is my radiator is not big enough to sustain level temperature. once i get a full size radiator yes ill go back to stock temp my gas mileage sucks with the lower temp but im not sad about it because i know why im doing it.

 

[Carlinator]

And yeah, overheating is bad; but the point is 228 is not really overheating in these cars. The OP was asking whether it being that high meant the gauge wasn't working; I trust that the Mazda engineers were competent enough to make the gauge read correctly in the normal operating range.

 

[CHIQLES]

228 is not over heating but since my fans turn on at 204 to drop temp down to 195 im just saying something wasn't working right...or it could just be how my car works.

 

[jscott]

Thanks for the input from both of you....Just to be clear i'm running a P5 radiator with FMIC....My concern was that i'm used to cadillac engines running much cooler than 230, I was hoping someone knew the "normal operating temp" for the FS-DET so I could put myself at ease on the issue or if I should take action....heat isn't the main issue for a blown enigne (I know from experiance with these engines that the rods are def the weakest link) but I don't want to run into a problem warping my head....head gaskets are cheap enough but if you blow a head gasket you are playing with fire on whether or not your head is warped....I am on my 3rd engine in the last year and would rather not build another until I can do it with completed forged with upgrades made to the head so I don't have to worry so much....since my last build i'm running 5 PSI boost (to be safe) so I really don't want heat to be a problem....again thanks for all the input, the more I can learn about our cars the better

 

[Spiced MSP]

from what Ive heard, the p5 radiators were slightly thinner than the msp radiator although it is a full size radiator. So, that could add to the problem

 

[jdwk]

3rd engine in the last year? Something is definitely wrong. The cooling fan trips at 205 degrees. I know I'll come in from some spirited driving and than fan will only turn on if I let the car sit in the garage for a while, meaning that even driving like a hooligan in Arizona it doesn't break 200.

I did stupidly leave my cooling fan out thinking it wasn't doing anything since it barely covers the radiator, and the condenser fan does not come on unless the A/C is on or the temp hits 235. 235 is still not terrible, but way too high for 5psi power levels.

 

[jscott]

the 3rd engine is because of stupidity so that is no blame but my own, but being the 3rd engine is why I want to make this one last lol....so I must have a problem somewhere in my cooling system to cause my temp to spike so high? my fans do work, I don't have A/C but I did hot wire it to make sure the condenser fan works....would wiring the condenser fan into the same circuit as the cooling fan help? would a bad T-stat cause the temp to spike? what about water pump?

 

[jscott]

My car never had the stock radiator in it so I wasn't sure what size it was....it had some POS very VERY small one in it with a small fan, it blew the side out of it so I went to the JY and got the P5 radiator....I know it's a single core but I figured being full size it would be ok....were the stock radiators duel core??

 

[shane02pro5]

Long story shortened version... according to my Haltech when I had a blown aftermarket fan relay boiloverpoint where my overflow was boiling over between 228-235?! This was back with stock radiator and 2 spal fans using both .9bar and 1.1bar cap and 170* tstat. This would only happen after a good 25psi+ romping then sitting at a light in traffic on a hotass tx afternoon. After replacing the relay I never exceed 220 after countless datalogs...

I would certainly say that you have an issue if your reaching those temps!? Stuck/bad tstat