High Engine Temperature in Traffic - my solution. - ZR-1 Net Registry Forums

Bruce · 07-16-2017

Hi People of ZR1 land.
Ive been concerned with the very high engine temperature when the car is in slow traffic or in town stopping at lights etc. I saw temps up to 118 degrees (as seen on the DIC) when stopping at lights or just driving through town slowly.

I know the radiator has 2 fans. I read somewhere that one is a primary and the other a secondary unit. Seems they dont come on at the same time and I doubt if the secondary one has ever come on. (a bit hard to check at the stoplights!)

Soooo I thought Id manually operate both fans to see what difference this made.
I hooked up a simple toggling remote control receiver in the engine bay with steering diodes connected to both fan relays. I can now operate the fan relays from a small hand held remote inside the car. I did this so I wouldnt have to bugger about putting a wire through the firewall and then to a switch somewhere - and to test my theory without too much effort.

Wow - what a difference. I have found now that if drive around town, I just switch on the fans and leave them going. Temperature never goes over 94 now, air con going, stop start traffic, hot day etc. Obviously when I get out on the open road Id turn them off. As my switching device is paralleled with the existing ECM, the ECM can still switch on and off the primary fan etc.

I'll probably consider looking for a decent place to put a small switch (possibly by the drink holder next to the ciggy lighter socket) then I can operate the fans as needed.

All this could be done from the ECU but I dont have the programming equipment etc. I could make up some sort of simple control using a Raspberry Pi or similar, or even some sort of discrete component system but I think Id just be happy with the simple switch. I think its something that us ZR1 owners tend to keep an eye on the temperature gauge so its not such a biggie to operate the fans manually.

07-16-2017	#1
Bruce Join Date: May 2016 Location: Whangarei New Zealand Posts: 29	High Engine Temperature in Traffic - my solution. Hi People of ZR1 land. Ive been concerned with the very high engine temperature when the car is in slow traffic or in town stopping at lights etc. I saw temps up to 118 degrees (as seen on the DIC) when stopping at lights or just driving through town slowly. I know the radiator has 2 fans. I read somewhere that one is a primary and the other a secondary unit. Seems they dont come on at the same time and I doubt if the secondary one has ever come on. (a bit hard to check at the stoplights!) Soooo I thought Id manually operate both fans to see what difference this made. I hooked up a simple toggling remote control receiver in the engine bay with steering diodes connected to both fan relays. I can now operate the fan relays from a small hand held remote inside the car. I did this so I wouldnt have to bugger about putting a wire through the firewall and then to a switch somewhere - and to test my theory without too much effort. Wow - what a difference. I have found now that if drive around town, I just switch on the fans and leave them going. Temperature never goes over 94 now, air con going, stop start traffic, hot day etc. Obviously when I get out on the open road Id turn them off. As my switching device is paralleled with the existing ECM, the ECM can still switch on and off the primary fan etc. I'll probably consider looking for a decent place to put a small switch (possibly by the drink holder next to the ciggy lighter socket) then I can operate the fans as needed. All this could be done from the ECU but I dont have the programming equipment etc. I could make up some sort of simple control using a Raspberry Pi or similar, or even some sort of discrete component system but I think Id just be happy with the simple switch. I think its something that us ZR1 owners tend to keep an eye on the temperature gauge so its not such a biggie to operate the fans manually.