120 degrees

[CPGCharlie]

Hi All, 

On Cold Startup my water temperature gauge climbs up to 120 and sits there for a good few minutes and only seems to drop back down to running temp after a blast up to about 70/80 - ( if i don't go above 30/40 it can sit at that reading for longer) 

After running for 10 minutes it's always at normal running temperature. 

The other day i did find some coolant around the rad and on the chassis below. could not locate a leak or weap. 

Could it really be running that hot or is it just a faulty sensor or wiring? if so it's a Duratec engine - which parts do i need? 

many many thanks 

[Jonathan Kay]

While we wait for the Duratec experts...

...

"The other day i did find some coolant around the rad and on the chassis below. could not locate a leak or weap."

I'd want to know where that's coming from. And liquids can track a long way from their source! I suggest cleaning everything and putting some absorbent white paper in relevant places.

...

How many electric cooling fans does it have and do they come on appropriately?

...

Let me know if you'd like the wiring diagrams.

Jonathan

 

[CPGCharlie]

Thanks Jonathan, I will clean and try to detect the source, however, I have just completed a Hampshire to Bucks trip over 5 days and no pink anywhere, so very sporadic. 

Just one fan on Rad and it does not come on unless i manually turn it on.... i guess that spells sensor is faulty? i will try replacing the wiring first as it looks fairly ropey. 

Charlie

[Dave Hardcastle]

The temperature sensor wire is at the rear of the engine, at the top. I knocked mine off while doing some other work. It might be worth making sure this is clean and has a good connection.

[ChrisC]

So you have two temperature sensors for coolant on a Duratec. On for the gauge and the other for the ECU.  The gauge is a bit of an afterthought, and the wiring is easy to damage, it's also easy to have a poor earth connection to the sensor causing interesting gauge readings.  

The sensor in a metal hose (called the submarine hose), at the back of the engine.  It's worth disconnecting the wires and checking the resistance to test the sensor.  

The submarine looks like this 

https://caterhamparts.co.uk/other/1624-cooling-submarine-temperature-sender-csr-race.html?search_query=Subm+&results=5

If I had strange gauge behaviour, this is where I would start.  Beyond that typical continuity checks to the gauge, replace the sensor (it cheaper than a gauge) then try swapping the gauge. 

Oh and the gauge isn't accurate to the ECU coolant temperature at anything but one temperature in my car, it's reads low to begin with, and high at the other end of the scale. 

 

[Golf Juliet Tango]

Gauges/sensors not giving accirate readings are not unique to Duratec engined cars. It is certainly true of K Series too, where in the same fashion the ECU & dashboard gauge receive signal from different sensors.

[StevehS3]

Are they inaccurate? Or is it because the sensors are located at different points on the engine/cooling system?

[ChrisC]

I think it's a general car industry thing, I.e it's not important, unless it's too hot or too cold, nobody cares if the coolant is 90 or 91c.  I suspect that's the reason why the gauge isn't calibrated, and then combine that with the two sensors you have enough reason for the inaccuracies, and no real desire to resolve it (always bigger fish to fry).

[ChrisC]

In this case I would also check for air locks, because there maybe a hotspot until the stat opens.