veilsidei

hi i have a 93 fd and the fans arent coming on soon enough by the time they come on the car is already boiling. is there a way to make the fans come on sooner. i didnt see a switch in the stock radiator. cause i just had a koyo racing radiator put in and it having overheating issues. and i notice the fans barly ever come on unless im at a stop and they come on for a little bit but not long enough for it to cool the car down so i am also wondering how you make the fans come on for a longer period of time. we checked the fan relay and it looks fine. cause the fans do come on when the key is in the on position not started the position were the lights come on the air conditioning and stuff. i run them when i turn the car off but i dont want to keep doing that and end up dying down my battery as optimas arent cheap.

CantGoStraight

Do a search for fan mod and then decide which route you want to take (there are several)

rynberg

Have you even checked your radiator cap? If it's not holding any pressure, you could be boiling off before the fans come on (which is at 221F, with the stock ecu and thermoswitch).

veilsidei

yes i put a new 16psi cap on and it didnt fix it and i just upgraded the radiator to a koyo last month.

veilsidei

i looked all the fan mods are not helpful they dont seem helpful for me = 18 with a FD which is not right i shouldnt have started with this car for a first car. ive screwed this car up so bad. 3 months of owning it i blew the turbos motor. now the new coolant seal is leaking and the car fans dont like to turn on ontime. so i am basicly not a good rotary owner. i cant take care of this car worth ****.

rynberg

Do you have a FSM? If not, download one for free from the sticky thread near the top. Go to the cooling section and start troubleshooting.

Unless you are really getting hot with the fans not running properly, my guess is that you are still not maintaining pressure. You can often rent or use for free a pressure tester to test your system.

scotty305

iTrader: (2)

^^ I agree with rynberg. It sounds like you've got two issues:

1.) The OEM fan control setup activates the fans at 230F, which requires your cooling system to hold 13psi of pressure to avoid boiling.

2.) You've probably got a bad pressure cap or coolant hose somewhere, which is allowing your coolant to boil at 212F because it's not holding 13psi of pressure. I'd recommend replacing both pressure caps (the one on the AST and the one on the filler neck) if you haven't already, and all the cooling hoses, and install a new OEM thermostat.




Here is a thread that you might find helpful:

The Big Fat FD3S Cooling Thread:
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/big-fat-fd3s-cooling-thread-571088/

-s-

magnus.rx7

Well be aware that the fan speeds vary depending on the temperature. Make sure that your fans are running at "high" speed (you can feel the draft strongly in your face) when your car is around 80C, or you'll be boiling coolant all day.

Also check the fan fuse. If it's blown, you'll only run in low speed. Go through the wiring carefully (tend to fray at the bend right above the fans). Make sure that the wires are in good condition and not shorting out. Good luck!

rynberg

The fans turn on low at 221F, med at 226F, and high at 230F, assuming no A/C.

Uh....no. Read above.

polyfc

for a temporary fix just remove the ac fuse push the ac button in and turn it on full blast. That will trick the ecu into thinking it's on and turn the fans on for the radiator

scotty305

iTrader: (2)

Really? My temp gauge must be a bit inaccurate... Thanks.

-s-

veilsidei

thanks for all this info. and there is another thing my coolant buzzor constantly goes off i disconnected the body electrical connnector to stop that annoying sound. but could what ever is causing this buzzor to go off also be causing this fan issue? weve flushed the radiator and i got a new koyo put in because the stock radiator seal blew and replaced the coolant level sensor on the filler neck.

rynberg

Did you guys properly burp the system? Doesn't sound like it....

CantGoStraight

Good thing you unhooked that sensor, it's only telling you there air in the filler neck not coolant. I agree with Rynberg doesn't sound like all the airs out of it or you have air getting into the system form some other source. Do you know if the caps are in the correct place ? ? ?

veilsidei

yes a 16psi cap on the filler and i think its a 10 psi on the ast not sure about the ast. ill take it to a friend and have him flush the system and burp it right. but its been flushed twice.

veilsidei

after i get my car back from the shop that screwed the engine over in the first place. my coolant seal is leaking and they are looking at it to see if they are gonna pay for the new rebuild.

scotty305

iTrader: (2)

A great way to kill a coolant seal is to boost without warming the car up. How are you monitoring water temps? Do you have an aftermarket gauge?

-s-

veilsidei

no its the stock gauge. my car is fully stock except for the radiator. and i let the car run for 3 minutes before i go and drive it.

CantGoStraight

You may want to get an aftermarket temp gauge so you can see how inacurate the stock one is. I think you'll find it's no where near warmed up when it's in the mid position on the stock gauge and will hold there well into a high tep condition......usually when you see it heading towards the top it's already overheated.

veilsidei

yeah well the shop set the fans to come on a 190. so i think the car is fine now they says its finally running correctly.

scotty305

iTrader: (2)

Depending on the outside temperature, your car will take a longer than 3 minutes to fully warm up (my car takes 5-10 mins to warm up at idle). There's nothing wrong with driving when the car's a little cold, but you don't want to boost until it's fully warm. This is because the coolant seals are sandwiched between a piece of iron and a piece of aluminum, and the two different metals don't warm up at the same rate.

Until you've got a temperature gauge that tells you real numbers, don't use more than half throttle for the first 5-10 minutes of driving. The needle on the OEM gauge doesn't even tell you when the car is warm enough to boost.

-s-

veilsidei

alright thanks ill do that for now on. thought the cold start idle 3k and 3 more minutes would be enough :P im a fd newbie.