Vtec04

I may be wrong, but I feel like it's not good for my engine for the radiator fans to not come on until 207 degrees in traffic. I know that it's "safe", but I feel like the engine would last longer and not heat soak as much if the fans came on a bit sooner, like maybe 195, but at the cost of a fraction of 1 MPG. Part of the reason that I am saying this is I feel like the engine idles a little rougher and feels like it's a little less powerful once it heats up from being stuck in traffic. I ordered a Hayden 3653 adjustable fan switch so I can turn the fans on at a lower temperature. My questions are first of all, will I be causing harm by turning the fans on at a little lower temperature, and second, what temp should I turn the fans on at? Thanks.

TomCat39

I can say that it's annoying as hell having the fans kick on every 5 seconds for 45 seconds.

I noticed the temp was changed on my tune which has aided in not constantly running fans when sitting idle after a long freeway drive.

I do not know any of the other pro's or con's to the change. With the exception of lowering too much can affect operations by reducing the temperature below optimal operation. I do not know what point that is though. Just that like going to high, you can go to low.

Vtec04

I'm not bothered by the fans running more often, so that's not an issue. I may be wrong, but I would think that you can't lower the temp too low by installing a lower temp fan switch as long as the thermostat is working properly. Thanks for the reply.

TomCat39

I do not believe you are wrong about that.

I was making a general statement that you can take the car operating temperature too low. As for how, I think you nailed it on the head about swapping the thermostat along with the fan thermo switch.

Vtec04

Thanks. I see what you're saying now. I believe in using OEM thermostats, and I have a fairly new OEM Honda thermostat. I agree with you that the engine won't run as efficiently if it is running too cold though.

JRCivic1

The thermostat and the fan switch need to be paired together. If the fan comes on at a LOWER temperature than the thermostat opens... the fan runs longer than necessary, reducing the life of the fan and potentially damaging fan wiring from the voltage heat. Fuses and relays are also at risk. So, in short... if you want to drop the fan switch operating point to below 195'F, you need to get a thermostat with a LOWER opening point than the fan switch.

Vtec04

The thermostat is a 170, so 190 is OK?

DCFIVER

You are.

I applaud you trying to learn,Im not much of a teacher,so I wont go into all the reasons why you are wrong.

If you are experiencing a drivability issue,Id look else where.

Like maybe two fuel injectors wired into one........

Vtec04

Thank you for your help. I am not having an "issue", and this has been going on since way before I wired the 2 fuel injectors together. The engine just seems to run slightly rougher at idle once it heats up, that's all. It still runs good. So besides gas mileage and slightly more fan motor wear, is it bad for the engine to not heat up as much in traffic? To me, it would seem that since running between 180 and 185 on the highway is fine, running at that temp in traffic would be okay also.