rotarymaz

iTrader: (1)

As title said, my idle started jumping between 1500 to 2200rpm as soon as the water temp hit 105 C. I recently had PFC install and car idles great at 1000rpm when temp is less than 105 C. I took a drive this afternoon, car maintain 100 C for about 30 min with mininal boost. (I'm in PHX and it was ~110 F outside today!) But then the temp started climbing and hit 105 and that's when the idle goes crazy. This has happen to me before on stop and go traffic on the freeway. So, I wanted to see if I could trigger the same situation and sure enought as soon as the temp hit 105 C, idle went crazy. I ease the car back home and temp hit 110 C at highest point. The fan was on when I got the car home, coolant level and hose was OK. My stock temp gauge never moved pass the mid point.

Any ideas as to why? Suggestion on trouble shooting? Thanks.

skir2222

OUCH! That's starting to really push it, I have a Defi water temp gauge and temps never go above 185º I have a greddy 3row fmic, press the ac button and put the air to setting 1 to turn my fans on and keep them on to keep temps low.

moconnor

iTrader: (14)

I would not bother trying to troubleshoot this. Get a Datalogit and set the fans to come on at 85-90C and you should not see anywhere those temperatures.

HawaiianRedMako

100 degrees C = 212 degrees F (boiling point of water)
105 degrees C = 221 degrees F

You're playing with fire at those temperatures, lucky your seals did not blow?

moconnor

iTrader: (14)

Actually, those are not outrageous temperatures for an FD. The stock thermoswitch only activates the fans at 108C. The default PFC temperature is 95C, which should prevent running this hot under normal circumstances.

Are you sure your fans are coming on?

rotarymaz

iTrader: (1)

Your refering to radiator fan right? It was on when I go the car back home. The car was doing fine for 30 min running about 100C, considering it was 110F outside. Changing the fan setting was going to be my next step, but curious if anyone else has had this problem and what's causing it.

dhowardFD

I have the same "problem". Above 103C the idle will jump the way you described. It's just the PFC trying to cool down your coolant temperature. I have not bought a datalogit, nor done a fan mod, but plan on both soon. Maybe you should look into the same. I also run a greddy fmic. Are your intake temps high, around 55C at about 90F outside?

rotarymaz

iTrader: (1)

Good to hear I'm not the only one with this problem. I'm not sure about my intake temp, but I'm sure it was very high, because by the time I got the car home and pop the hood, the engine bay was burning hot. I currently have a Blitz intake and stock intercoolor, but will be switching it out with a PFS SMIC and intake. Hopefully that'll help a little. I read that running a 70/30 water/coolant mix will also help in hot climate area. I'm going to flush the radiator and do this and see if it does anything. Can anyone confirm if changing the coolant mix will help at all? Thanks.

Eggie

Sounds like things went screwy when the thermoswitch closed. I'd check the thermoswitch & fan wiring.

mad_7tist

105 is not dangerous. the idle quality has nothing to do with the coolant mixture. why is it idling at 1000rpms to begin with? what mods are done?

rotarymaz

iTrader: (1)

I'm NOT saying changing the coolant mixture for the idle, I'm saying changing the coolant mixture to 70/30 to help with the heating issue. Since water has better heat transfer properties and it's 110F here in PHX all summer long. The mods to car are intake, exhaust, downpipe and koyo radiator.

Envisioned7

i know that mine personally doesn't idle very comfortably until around 900rpm..so 1000 hardly seems like a stretch..