Anyone had extensive experience with the FC cooling system? I don't mean just coolant changes. I've redone pretty much the whole system on my new turbo but she's still running hot. Any tricks to fully purge the system so it will stay cold? I have what I think is a pretty good radiator/ E fan set up, thinking about moving the E fan to the front of the radiator and running the clutch fan with it. Any thoughts?

1989 Mazda Rx7 FC3S GTUs #10

 

Define "running hot" and how you gather the data.

Your fan idea would be a disaster for a number of reasons, suffice to say "no".

 

Well I bought the car pretty cheap, and the POs heating system was a disaster. I put in a corksport radiator, new hoses, thermostat, and water pump. Did a full bleed and purge and I took her out for a test run last night and she was over half on the temp gauge after only a mile or so after warning up and I turned around and went home.

1989 Mazda Rx7 FC3S GTUs #10

 

First you need a real temp gauge.
"Halfway up the dial" is a meaningless statement.

 

I am battling this issue currently as well, however I have a FMIC and an aftermarket water temp gauge on the water pump housing.

Have you verified the thermostat is fully opening? Also ducting is extremely important to these cars. Ensure that you have the factory under tray installed. Use thick HVAC foam to seal up any gaps between the radiator, under tray, oil cooler, AC condenser, etc.

 

so what does your aftermarket gauge tell you?

 

I had a greddy gauge, but the wire just broke like two days ago. I'm going to install the clutch fan and the under tray tonight. start with that I guess.

1989 Mazda Rx7 FC3S GTUs #10

 

You could start by actually defining the problem you think you have.

 

top mount intercooler?
ac condenser still there?

 

[QUOTE=Turtle13;11739995 I'm going to install the clutch fan and the under tray tonight. [/QUOTE]

those are important pieces..

 

A pusher fan is only for a dire situation where a puller will not fit between the radiator and engine. Pusher fans are less efficient than puller fans.

Follow the bleeding instructions in the factory service manual (FSM). Also, make sure you use distilled, water and use the coolant/water ratio listed in the FSM with the most water possible for the temperature range of your region.

Also install the OEM radiator shroud and the OEM plastic panels that are to the right and left of the hood latch. Quite often cooling problems are caused when people remove critical components that they misidentify as dead weight.

 

Pics would eliminate a lot of confusion in this thread. How about a shot of your "pretty good" e-fan setup.

 

Maybe I'm falling short of the mark here, but don't S5 dashboards have the coolant gauge that hangs out about halfway over a wide temperature band?

If it really is overheating with a properly bled cooling system, and all the pieces installed (to include the undertray) then start suspecting either a non-oem thermostat or bad coolant seals. Understand that diagnosing a car via messaging is always difficult. Pictures and numbers work wonders.

 

Yes it does, which is why I said his description was not very useful.

 

Yes as clokker said. S5 gauge basically reads cold, normal, and cooked. I have seen my autometer gauge hit 230F and the stock gauge never moved.

 

As a few said, the stock S5 gauge is misleading (putting it mildly). Get your aftermarket gauge working, as well as the clutch fan and undertray like you said, then see what's up. Is the thermostat a Mazda one? That's usually preferred here. Is your upper rad hose hot as in "burn your hands" hot when fully warmed up?

And someone asked if you had the top mount (stock) intercooler and something else. Also, tell us more about the fan and take some pics of all the stuff.

Going back to talking about the clutch fan - many fan clutches aren't doing their job any more. They're not cheap though, but cheaper than an engine.

 

Get yourself a digital gauge. replace your sender. make sure your plastic under fairing is installed and get yourself radiator panel for the space between the rad and bumper.
If the car was running better before you messed with it, double check everything you did. Make sure your e-fan is shrouded over the entire rad. you want the fan to pull air across the entire rad. not just the area of the fan.

 

Thanks everyone for the inputs. Apparently that E fan sucked. We put in the clutch fan/shroud, under tray, and bled/burped the system fully. Took her on a long drive and it was the coldest any of my Rx7s ran. She runs like a top now. Thanks!!!

1989 Mazda Rx7 FC3S GTUs #10

 

That must have been one really terrible efan.

 

Must be a eBay efan they just junk