dra_gon_lee

I have a 87 T2 with a few mods, nothing major, and I was wondering if i was running too hot or not.

I have an electic fan, the permacool 2800 cfm, wired to a switch that i turn on so it stays on all the time. During nighttime its fine with the stock coolant guage at around 1/4 unless i stomp on it for a long time, it gets up to about 1/3 to 1/2. When i drive during the day ( in Texas btw) it gets up in the 1/2 and stays there no matter what. Am I overheating? A guy I know says the guage should never go past 1/4, but he lives in cali, and it gets a hellofalot hotter here than there.


thanks for any info

rocky

Ryde _Or_Die

I dunno are you running hot?lol. Well 1/2 way up would concern me too but thats not too hot for TX I guess. Do you have a shroud with that fan? The bottom plastic piece on as well? How long does it take to get that hot anyways? Might wanna just change the thermostat and flush the coolant as maintence if it hasn't been done recently and see if it helps. Your obviously not over heating but running warmer than you'd like right?

dra_gon_lee

you got it, i did the thermo, have a shroud, and flused the coolant, put in 70/30 prestone water, and water wetter... i don't have the plastic bottom peice, should i get that soon? also i want to make the radiator deflector peice too...

Ryde _Or_Die

Ya might try to get that plastic bottom piece. Also do you have the original radiator in there? I know with my fluidyne I saw a huge difference. You can have it rotted out or look for a new one. You can get a replacement for like $200-300. I am pretty positive that the radiator is at least one of your problems.

fuzzi

I think the first thing you should do is get an aftermarket guage.. the stock guage is so unreliable you cant guage the temperature at all with it, its absolutely useless. I have an aftermarket one installed now, and my old stock one is still hooked up, and when my car gets warmer by 20 degrees the stock guage doesnt even register a difference, not to mention the stock guage says its warm even before it actually is... id say replace that first than worry about overheating.. my 0.02 cents

dra_gon_lee

i have an aftermarket guage, really crappy, but aftermarket, it says im running around 190-200 at the hottest.... whats a normal operating temp?

and i should hope you would see a big difference if you drop in a 400 dollar rad...

NZConvertible

What's the point of that? The fan is only required at low speed or when stopped. Any other time you're needlessly drawing a high load off the already weak alternator, which draws power off the engine. So you've lost the main advantage of an electric fan. Do it properly; get a thermoswitch. The temp should stay pretty constant day or night, even in Texas. Those missing shrouds and undertray will definitely be contributing to the problem, as most of the air entering the nose will be going above and below the radiator instead of through it. If that new thermostat isn't a Mazda one, replace it. If you still have problems, a blocked radiator or a rotted water pump impeller are the most likely causes.

akageals

I have been chasing a similar problem but mine would get up to about 3/4 on the interstate with the A/C on. I put a new water pump and housing on it. Flushed the radiator, new hoses etc. . It still gets up to 1/2 on the intersate with the A/C on. 1/2 is well within the normal operating temperature on the factory gauge. I'm wondering why we all think that the gauge must stay at 1/4. I'd say 3/4 is a little high but I would not be worried about 1/2. Assuming the A/C is off the electric fan kicks on when additional cooling is needed (it runs all the time when the A/C is on) so.....if the electric fan is not running (assuming it's working OK) I would not worry about it.

Todd

akageals

One more thing....I do agree with getting an aftermarket gauge. I'm going to do that soon. Anybody know the best place to purchase good quality gauges?

Todd

jimmyv13

I like Autometer gauges, so I shop at Summit .

dra_gon_lee

the switch works alot better than my switch... the switch would come on too late, even though its set to come on about 180. I saw a more consistent temp with the switch. I do have the shroud, i just don't have the bottom tray, which i think is the biggest problem right now. The deflector tray I was referring to was the one you make to cover that piece right in front of the radiator. After I get both of theses pieces if im still not ok, ill look into a sbc Alum radiator conversion.

deadRX7Conv

Do not trust your dash gauge. It is there for ***** and giggles. As long as it doesn't shoot up to red or move quickly(bounce), then there is no problem.

190-200 is normal operating temp for your crappy gauge and for the engine. But, it all depends on accuracy, quality, and what this gauge connected to.

I was looking at the FSM. There are some rx7s(auto tranny??) with electric fans. The switch turns on above 207f(97c) and switch is off below 194f(90c). I would think that the thermoswitch you have is working properly. If not, try to find one of those adjustable ones.

The manual switch can still be kept. You might want to keep it if you haven't wired the A/C to the fan. Or if you want the added BTU reserve of leaving it on prior to a race or while in traffic. Just remember that you need to flip it off when you stomp on it. I would think that 2800cfm is putting a 10+amp load on your alternator.

And, you should always use the genuine Mazda thermostat.

NZConvertible

What switch are you talking about? Do you mean the one for the factory electric fan? That fan is only there for the A/C and if the coolant gets to 207ºF. Were you running your new electric fan off that stock switch? With a proper aftermarket adjustable thermoswitch, you shouldn’t have any probs with low speed cooling. If the plastic should in front of the radiator is still there, you don’t need to make anything.

deadRX7Conv

Permacool sensor failure after a year here:

http://rx7.voodoobox.net/howto/efan/efan.html

dra_gon_lee

i have a genuine mazda stat, the switch is wired to the hot side of the battery and thermoswitch... so if i turn the switch off the fan works off the thermoswitch. the thermoswitch is a good adjustable one, the one that permacool sells.... any other things anyone can add to this, as i think i have gotten the answer to my question......


thanks
rocky

SureShot

My 87 temp guage ran between 1/2 and 3/4 normally. 7/8 was the boilover point. My 91 run 1/2 under all conditions..
Bill

Angel Guard Racing Team

Check the water pump/alternator belt, if it is streched the water pump will not do it's job 100% right... Check the radiator to see if it is clogged...