420 Running Hot ?

[mschraider]

Hi All, 

I’d welcome some thoughts on whether my car’s current behaviour is common or not. 

The temperature the car runs at seems to have changed over the last few outings ( I guess also impacted by the glorious weather ). It used to sit quite comfortably at an indicated 90 degrees and would be able to sit in traffic for a while before the temps rose and the fan kicks in. Now, cruising at 50 or above keeps the temp at 90, anything less and the temp rises quickly and the fan cuts in. 

It’s never overheated, it’s just that I’ve noticed the change. 

I did fill it with vPower by mistake in the previous fill up, would that cause it to run hot ? 

Grateful for any guidance. 

Thanks

[ChrisC]

So my gut feeling is you car is perfectly normal. 

I had a different problem with my 360 when it was originally first on the road.   The fan would cut in before the thermostat opened, therefore the fan was trying to cool a radiator that didn’t have hot water passing through it.   During my investigation of this issue I discovered a couple of things that might be relevant to your car. 

1, The gauge isn’t accurate, I.e if it reads 90, the ECU won’t be reading 90, they use different sensors.  My gauge tends to over read the temperature. 

2, There are two thermostats for Duratec engines a 82C stat and a 105C stat.   My car had a 105C, which is the norm for 360/420 cars, therefore I bet your running temp is 105C

If you want to check for my cars problem, just check it the bottom hose is cold when the fan starts, if it is then the fan is over acting.   I fixed my problem by fitting the 82C stat, but I could have got CC to adjust the ECU fan settings.   However as I said I suspect your car is working normally.

[ScottR400D]

Chris, do you know why there are two stats on Duratecs? When did they change?

My car seems to have the 82, it was new in 2015. 

[mschraider]

Thanks Chris, very useful. 

[Jim 123]

Scott I'd suspect that change to the hotter thermostat would be a latter action taken by Ford to improve measured emissions / economy.

[ChrisC]

Scott based on your comments sometime in 2015,  my kit was October 2015 delivered, so a very early 360R, hence I had an ECU that was expecting an 82C stat and a fan that came on at 100, but a stat that didn't open until 105, so the fan run constantly.     

[ChrisC]

Agreed, must have been a Ford change for improved emissions.   Swapping my car to an 82 stat stopped my fan from running constantly, and massively improved access in the area being a smaller stat housing and a S3 car, before that space in that area was at a premium. 

[mschraider]

Thanks again Chris. 

I’ve done some testing this afternoon based on your guidance, and I’m now suspecting it’s just the increased ambient heat causing the normal running temp to just sit a little higher. 

The thermostat seems to open at 95-100 and the fan seems to kick in around 105. The bottom hose runs hot once the thermostat has opened, and all of the coolant hoses (including the heater) seem about right. Running the heater full blast also helps slow how quickly it gets hot, but that’s not something I’d be wanting to do on days like today ! :) 

I ran ran the car up without the expansion tank cap, hoping to bleed out any air that might be present, and all seems good. It’s also still not dropped any coolant. 

I’ll get CC to check things over when it next goes in, but I guess currently it all looks good. 

Thanks again. 

[ChrisC]

Your car sounds fine 

[CtrMint]

Your car sounds identical to mine too.