So I've been doing some data logging and was shocked to find that my engine coolant temperatures sit fairly steady at 60c after warming up. This is of course way lower than you should see on a fully warmed up engine, with the factory thermostat trying to keep the ECT at ~80c.

So I checked and double checked my sensor calibration. I am currently using the AEM calibration and am aware there is a different calibration available here https://www.s2ki.com/s2000/topic/184...-calibrations/ however that calibration would put my ECT even lower at ~55c fully warmed up.

So the obvious answer to this would be that the AUDM ECT sensor is different to the USDM ECT sensor. Can anyone confirm or deny this?

AEM users, what temperatures / raw sensor voltages are you seeing when your car is fully warmed up? Are you using the AEM cal, the GR cal or a different one altogether?

 

which aem model ?
what's your definition of warming up ?
i live near a motorway and it takes me about 20mins going at 100kph before oil temp begins to stabilize , in contrast water temp should be around 85C after 20mins on the motorway (obviously give or take a little depending on ambient temp)

 

I'm using the AEM 30-6052. My definition of warming up is waiting for temps to stabilise. The picture shows a datalog from cold start, it doesn't go above 61c and dips down to 57 in parts. I have 40 min datalogs from freeway runs showing exactly the same steady 60c and am confident it's not going to climb any higher in normal driving conditions.

 

Have you measured a stable operating coolant temp of 85c through the AEM? Or do you just mean that any S2000 should be at 85c after 20 mins?

 

I have a 30-1012 and a AEM Serial gauge. I am using the modified calibration tables (not sure if the same as your link).

I have the stock thermostat but an aftermarket radiator.

Car takes a while to warm up then sits at low to mid 80s. With traffic driving it can climb to 90 but won't go much higher than.

Your graph looks decent but just miscalibrated. I'll fire up my PC later and post my calibration table.

Be sure you're unit are set to Celius too.

 

Thanks appreciate it, this one is starting to bug me, after spending the day at the mechanics who flushed the coolant and checked the thermostat to no avail.

 

i didnt check the coolant temp on the aem log, only on my stand alone gauge that has its own measuring sensor that i have plumbed into the system.

if your coolant was truly 60C your dash gauge would only ever be 2 bars on an ap1, cos it doesnt flick over to 3bars until 73-74C.

will have to check the computer next time i go for a drive in the car, which is not for quite a while

 

As I have the AEM series two, it drives the dash gauge and it does sit on 2 bars most of the time. Sometimes it will climb to three when idling for long enough but the majority of the time it sits on 2.

I ordered an infra red thermometer yesterday so I can get an idea of the temps inside the radiator.

 

^ Shoulda just gone to your local Coles / Woolies / IGA if you have a mate that works at one and just use the temp gun for 2 minutes in the parking lot.

 

This is my cal table with conversion to C: