I suspected for a while i had a sticking thermostat, however it warmed up fine and was rock solid at 84c - I didnt mind as it ran a bit cooler.

Anyhow to cut a long story short i had a problem with raising temps after a couple of month, it happened twice and was fine for a month then rose, i bled the system and all was fine for another month then it happened again, cue another bleed and it was fine.

I had the thermostat replaced but at the same time the rad cap as this could explain the gradual problem, the garage said that when they put the old thermostat in boiling water it never opened - which i thought was strange as i always monitored it.

It now hovers 'mainly' around 88c but before 84c (fully warmed up long drives), is this normal? what temps do you get? - i tend you add water to pre-mixed coolant as we never see freezing temps its designed for.

The problem is that ECT effects the AFR.

I use torque on Android to monitor it.

Cheers

 

torque normally shows coolant temp around 90C at idle after a run but then it quickly goes to about 98c and then the fan kicks in.

Engine coolant does effect the map but normally its only when the coolant temperature is lower. I would imagine once it gets to 80c it doesn't alter the map too much

 

ta, on a run its more or 88c.

The AFR is richer when hotter and leaner when cooler.

 

84 - 87c for me

 

Here's some temps on a track day - around 90C

 

My Scangauge has happily reported 88 for some time.

 

looks like its normal then at 88c thanks chaps

 

Having mugen thermostat and fan switch installed my coolant temperature reaches up to 82 degrees celcius where the fans kicks in and goes back to 74 degress celcious. It will do that all time long This is with normal driving. If i do pulls or at highway speeds and during summer time it can go up to 90 degrees

 

From the ScanGauge I get a water temp and an intake temp. once warm the water stays between 86-94 most of the time. IAC can vary widely but is usually 8-12C above ambient. That can get silly high if your stuck in town traffic where i've seen IAC of above 50. I suspect that the oem sensor values as read out of the OBDII port are damped as they don't tend to change very quickly.

Older cars would read higher IAC values due to the change in sensor location.