Sorry i misspelled coolant. Tightening the belt lowered the water temp but the oil temp is still high. How hot can the oil run before its to high and i should start watching it? How high before it causes damage? Thanks everyone for your input.

If you want to correct people's spelling, you should learn to spell nitpicking :)

my pal called mazda for an undertray since mine is missing and they wanted $400. thats just insane :\

I know that shine made one for the FEED front bumper. That is where i bought mine from. Mounted up real easy.

cool, ill have to check them out then because i need one

Buy a used one in the parts section.

Undertrays are a dime a dozen. They go for at the most $125 if Im not mistaken. Im selling one right now as well.

So I installed the undertray. moved the oil coolers up so they are sitting on the bumper. Installed a pettit racing 180* thermostat. burped reburped and the burped the system again to remove all the air. Took it for a spin and the car over heated again.

oil was 220 and water was at 210 and was rising. This was up a slight up grade. Going home it still ran hotter than i wanted it but water was still close to 210.

Could it be the water pump?

If the water system isnt working does it transfer heat to the oil?

Also have a FMIC flush with the bumper could that cause the car to not get enough air to the radiator?

I have the a/c "cooler" (sorry i dont know what its called) sitting in front of the radiator. any effect on the cooling system?


As soon as i shut off the car the oil temp drops real quick. water just sits there. I have to circulate the water to get it to cool down. I think its the water pump but not sure.......

IIRC, water pumps leak out the weap hole on the bottom of the water pump behind the impeller when they are bad. Any leakage from there?

I have a brand, spanking new water pump in the garage if you are looking to buy one.

No leakage that i can see. I thought maybe it got hot and isnt pumping as good but still together if you know what i mean. but i have done so much i am lost now.....

Have you verified that the water pump spins freely with the belt removed? Might be something to check if your suspect of the pump.

Also, are these test drives on the highway at highway speeds for extended periods of time? Or low MPH, stop and go situations?

Reason I ask is if the rad fans are/ are needing to engage. Regardless of if the fans are working properly or not driving at highway speeds should be able to tell you if every other piece of your cooling system is operating the way it should...

Do you have a yellow Lisle funnel that you can insert into your fill neck and run the car to see if your're getting air bubbles? I hate to even mention this, because if you're seeing tons of air bubbles the shop that reassembled your motor in Vegas could have pinched an O-ring on reassembly. If you're getting any kind of "pressurization" in the engine, that could cause the overheating that you're observing. Just a thought. Also not sure how and where you're driving in Vegas, but if you're stuck in traffic for any length of time on the strip and get heat-soaked, it takes a lot of time to bring down your temps. Just a brutal city for rotaries, FDs in particular.

Oil temps above 230 make me very nervous. 260 for any prolonged period of time will do damage to your bearing surfaces IMO.

The water pump spins freely and there is no play with the shaft.

I am driving on highway speeds 70 mph or less in 5 gear for a 2-4 mile road. temps are 200* oil and 180* water before i get on the high way and move up as soon as i get on the highway. Fans kick on at 180* ish.

If the the O-ring was pintch then i would be using coolant correct?

If the motor is bad the shop will rebuild the motor no questions asked. I know this because they just rebuilt a FC motor that had less than 2,000 mile on it. Young kid that was drifting it with no ECU and higher boost levels. They pulled it and it is in cali right now getting rebuilt.

I only had high temps over 230 before the rebuild. I dont letting the oil temp get over 230 or the water temp to go over 215.

That is very interesting. Def not something to do with the fans then. Are you running an AST? Or have you deleted it?

I dont think I have an AST. Do you need one on a single turbo? Fans work i know this and the temps drop fast when i am at idle.

Doesnt have to do with the turbo. Any fd can be run either way, just depends on what you wanna do. I just remember hearing, and I also witnessed it first hand, that cars with no AST have a harder time burping the system. My car used to have no issues with this when I had an ast, but when I deleted it it was a little more of a pita. Have you followed the standard procedures to remove the air bubbles? If so, what method did you use?

Then its deleted. I dont have an AST. I have the shop in vegas burp the system. I dont know how they do it but i hope all the air is out of the system. Would this explain the high oil temps?

It wouldn't be "using" it per se. Exhaust would be entering the cooling system and pressurizing it, hence it would probably start blowing out the overflow.

OK, so your current temps running slowly (50 mph or less) are 180 ish water and 200 oil. That's fairly typical for your climate, especially considering that you're running a front mount. If you've reinstalled the undertray, make sure to block off any places where air can escape underneath the car to keep air moving through the IC, rad, and oil coolers. Have you checked your coolant cap to ensure that it's holding pressure?

Have you tested the cap? I've bought several "new" ones from Mazda in the past that I tested and they wouldn't hold the proper pressure. Put your ear close to the cap following shutdown and see if you hear any slight hissing sounds. Is your coolant level staying topped off the day following a drive (i.e., when completely cooled down), or is your overflow slowly filling up and are you constantly having to "top off" your system? Just trying to kick every possible tire. Is it possible that the thermostat is somehow installed improperly??

Also might be helpful if you post up the ambient temperature when you're taking your test drives...

WOW... check that out... my 1000th post. :)

Hey Curt... another thought. If you're doing these tests above 100F and are taking the car up some fairly long uphill runs, you'll be hard pressed to keep her "cool" or even steady in the summertime when it's this hot. The FD is notorious for coolant temp "creep" in the summertime when temps get above 100F outside.

By long hill what do you mean? I take it up a drive on the highway and the only way i know its a hill is because the car will heat up. It is not a noticeable hill. I take it for a two mile drive and the car will overheat. Not a long trip at all i dont think. It would be like driving in tucson and the car overheat on the approach to Mt Lemmon and having to pull over before i even get to the Mt.

Would this cause a high oil temp?

I have th undertray that fits tight against the bottom of the car. I am about to pull the A/C out so there isnt anything that obstructs the flow of air into the radiator. I will check the cap on the today after i drive the car. I dont have to top off the coolant everyday. Thermostat is installed correctly.

Also temps are with the heat on full blast on defog.

By long hill, I mean a steady uphill grade for several miles. This will definitely cause your temps to start climbing, especially when your outside ambient temps are above 100F. Once ambient temps drop below 90F it doesn't seem to climb as quickly (in my experience). With dual oil coolers your oil temps should pretty closely parallel your water temps, with oil temps being MUCH cooler during the winter months. Heck, I almost need to block one of my coolers off in the wintertime just to get the oil operating temps in the 160F+ range while cruising. Oil temps will be slightly higher than water temps under LOAD, but should come down quickly once you start heading downhill and remove load, even in summertime.

Is your radiator still mounted in the factory position?

There is your problem right there. Look carefully in the t-stat housing. If you don't have a t-stat, 80% of the hot coolant will not flow to the rad but straigth back into the engine.