Ragincajunsmh

I replaced the fan w/ an eletric one, replaced the thermostat and the cap still over heats but not as fast. take about 30 to 45 min to get to 3/4 temp then climbs fast.

Some one help
please


Steve

Sniper_X

you have a brans new thermostat that is broken.

also you have changed your fan and should return to the stock on until this is solved.

unless you can guarantee that the replacement is capable of blowing you on your *** and therefore is certainly not the problem.

i would bet that the thermostat you have is broken or the wrong one.

MazdaRx7Power

either that or the fan you bought isnt strong enough.

bdc196

It could also be other things that he hasn't mentioned yet. Are you running a heat exchanger core in-front of the radiator that may be impeding front air damn airflow? That's one thing. Secondly, is your new fan shrouded around your entire radiator or just a part of it? Thirdly, what's the CFM rating of this new fan? Fourth, when you changed the thermostat out, did you ensure that you let the engine run long enough w/ the cap off to pump all the air bubbles out when the engine reached operating temperature?

When did this start happening and what was changed just prior to it happening?

B

Ragincajunsmh

well the electric fan I have is the same a friend has on his 7. I don't know if the thermostat is bad. maybe I will need to chec that. but how do I tell if it is bad. I ran it w/ the cover off toget the bubbles out. I just bought the car and is was not running when I got it. So now I am working out the bugs. I have a new water pump and radiator on its way. Hopefully that will fix the problem.

Ragincajunsmh

another thing does any one have the factory service material. I would be much obliged to have it emailed to me

Cheers!

goto fc3s.org

NZConvertible

Once the car's up to speed, the electric fan shouldn't make any difference. It it's overheating when moving, it's could be any number of things: thermostat, blocked radiator, air in the system, etc. If it's overheating when stationary the fan may be too small or whatever you're using to control it isn't working or is set wrong. Take that thermostat out and test it as described in the FSM. Download the cooling system chapter from www.fc3s.org, the instructions are on page 3-13.

J-Rat

iTrader: (2)

The electric fan is good, its the same one that I run in mine...A 16 in fan. And my other friend runs it too. I have been out to work on this car, and believe me, its overheating for NO apparent reason. The only thing I can think of is Water pump or radiator problems. Or maybe clogged exhaust. The seals are good, there isnt any bubbling on startup. And it takes 20-30 mins before the car starts overheating. Any ideas>?>

Rat

Sniper_X

So it should be acedemic to see what the problem is.
you chould check the thermostat in hot water.

check the car for pressure at the top hose but non in the bottom.

Remove the water pump face and the thermostat neck.

make sure that the thermostat is opening.

make sure that there is no play in the waterpump shaft.

im betting its the thermostat somehow.

J-Rat

iTrader: (2)

Okay dood...If heating problems are so flippin easy, here is the deal:

A. The thermostat is NEW
B. The cooling system has pressure and the heater is exchanging.
C. The water pump is solid.

For ***** and grins, we are gonna replace the thermostat again. I am not dumb, I know PLENTY about the "academics" of cooling systems, but this one is really out of the ordinary. So, any ideas?

Rat

Sniper_X

If the heater is hot, (which this is the first mention of the heater..) then the thermostat is opening.

Perhaps could it be closing agin for some odd reason?

How about removing it (just to see it fit overheats).

I have opened two broken mazda thermostats in a row before.

I installed them both.

It took a long time to figure that one out.
I mean no way two could be broken in a row.

After 30 mins, you dont have a hose collapsing do you?

J-Rat

iTrader: (2)

Removing the thermostat is an option, but it can only be temporary. Removing a thermostat in a car here in Arizona with summer looming around the corner is pretty close to engine homicide. It will run okay in town, cause the water should spend enough time in the radiator, but the highway is out completely.

Sniper_X

this is why i said "(just to see it fit overheats).
"

J-Rat

iTrader: (2)

The only reason I clarified, is that sometimes people in northern states (IE really cold places) love to take thier thermostats out because they can get away with it. Since I see you are from Ga, I am gonna assume you dont fall into this category. But yes, the heater is working, like I said. Usually it only takes a few minutes to overheat a motor that is not cooling itself. Why this one is taking 20-30 is BEYOND me. When my clutch fan crapped out, it only took a little while to heat up.

Well, he just called me, and said the electric fan he got only pulls 1100 CFM through a radiator, which is not enough, by a long shot. So we may have found the problem.

Rat

Ragincajunsmh

well I put the old fan on and took it for a long ride. ran about mid tep. that is the highest it got with heater on and all. all i need now is the housing that the cover goes on so i can have the overflow tank in place. Rat we need to get that other car.

I am going to bring that other fan back and get the better one. I have both running right now. It blows very well. thanks for all of your help.

Stevo

J-Rat

iTrader: (2)

Didnt you take off the lower cooling cowling? I saw it in your garage. That needs to be reinstalled.

Rat

Ryde _Or_Die

Ya cooling problems should be easy but they are not always. In my NA, I:

1. changed thermostat(checked to make sure it worked)

2. changed water pump

3. flushed coolant and added correct blend

4. checked fan clutch

5. checked radiator

6. checked hoses

7. checked water seals

8. had all parts on(fan shroud, bottom plastic piece)


The car would still run hot so thats why it has been sitting for months. If my local rotary shop can find out where my coolant is going in my TII and fix it then I might take my NA there.

Sniper_X

I remeber the first reply being "you have changed your fan and should return to the stock on until this is solved"

Im glad this was it.
Electric fans have to ba able to really put out ALOT of CFM to work on these cars.

J-Rat

iTrader: (2)

Yeah, but mine puts out about 2800 CFM and I run plenty cool...

Sniper_X

If you're saying that you both have the same hi output fans, then somthing is probably wrong with his.

Maybe the motor isnt as strong..
I know one guy that put a pusher and a puller fan in front and behind his radiator.

Worked VERY well.

J-Rat

iTrader: (2)

No, he got a different fan. I was under the impression that he had the same one, but I was wrong. Pusher and puller eh? I am thinking about trying that.

Samps

Maybe he has too much water in the mixture.

J-Rat

iTrader: (2)

Ummm....Huh?

NZConvertible

C'mon guys, think about this. Fans are for low speed or when stopped. Above ~15mph they are completely unnecessary because there so much air is entering the front of the car.
Steve, I asked before if it was overheating while stopped or after driving at constant speed, but you still haven't told us. This is important for us to diagnose this for you.
I also said this before but no one's mentioned it again: blocked radiator. Have you checked this? Have you tested that thermostat yet?