C30 General : Coolant temp ?

[Thassos]

Just wondering what the coolant temp should be when warmed up, im seeing 70c on a petrol 2L (the ford/mazda) engine (07 year) C30 seems a bit low to me? what should you see (im reading it thru an OBD adapter from the ecu)

[cheshired5]

Operating temperature is a degree or two below thermostat rating so if they still put the thermostat opening temperature in the owner's handbook, check that.
Mine is a 90°C thermostat so coolant temperature hovers around 88-89°C once warmed up and stays there.

Regardless, 70°C sounds low for any engine.

[Thassos]

Thanks cheshired, did a longer run with it and it got up to 80c.. i did find the following in the volvo handbook,

The thermostat starts opening at:
90 ºC in petrol engines, and at 82 ºC in diesel
engines.
petrol engine (1.6) 82 ºC
diesel engine (1.6D) 83 ºC

so looks like 90c it should be, curious.. could the stat be faulty or is this difference normal?

[oragex]

See this https://www.youtube.com/watch?v=gQxQnuU22Ow

I think you should have around 85C on just cruising down the road, and close to 87-90C after an acceleration.

[Thassos]

Would anyone have a diagram or info from vida of where the stat is located?, engine is a petrol 2L B4204S3, (2007)..

Noticed on some other posts talk about a secondary bypass coolant valve controlled by the ecu, but this was a diesel so not sure if petrol engine has the same, maybe the mechanical stat is stuck open so its not getting up to 90c quickly, the video implies this might happen after very cold weather, or 10 years both of which apply.. but couldn't find any posts on here so maybe its not a very common fault?

[cheshired5]

Originally Posted by Thassos

Would anyone have a diagram or info from vida of where the stat is located?, engine is a petrol 2L B4204S3, (2007)

[Thassos]

Many thanks cheshired, perfect !,,

Have been doing some further checking and felt the temperature on the various hoses, the large rad pipe coming out of the stat on the lhs doesnt get hot as the engine warms from cold, the other smaller pipe coming off the stat does, as do the 2 small tubes that run to the expansion bottle around the edge of the bonnet release area, so this leads me to conclude the stat is infact not stuck open, when driving i was able to see a max temp of 85c using the obd maybe it just takes a long time to get there.

One thing i did learn is that the temp gauge on the dash isnt really like a traditional gauge and has some big software tweaking going on , as it stays in the vertical position from 70 up to 85, with no movement, is more like a confidence gauge (vertical is temp in expected range kinda thing), so you probably wouldnt get much of a clue if it only reached 70c..

Did some tests also on my D5 diesel and this stabilises at 88 to 90c on the run, but also takes a fair time to get there when idling which i guess you would expect, but seems petrol and diesel coolant temps are not too different..

[SwissXC90]

My D5 diesel can go from 9°C ambient garage temperature to 89°C normal engine temperature in 3 to 4km driving, whereby the last 1km is uphill.

But my diesel does have the fuel-burning engine heater fitted