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Hock
08-23-2009, 08:03 PM
Our cars get the engine temp from the coolant. Newer cars use the cylinder head temp. Would there be any benefit in switching from coolant temp to head temp?

Now before starts in about wiring, I know that it would have to be redone as well as the EEC would have to be re-tuned to make it all work properly.

My question is whether or not it can be a performance benefit getting the head temp over the coolant temp.

Mike8675309
08-23-2009, 08:56 PM
Which newer cars? Our sensor is in the intake manifold at a point where coolant is crossing over from the two heads on it's way towards the thermostat.

Head temp will be higher but I would suspect that if someone is putting a sensor in the head itself, it is due to some variable necessary for a strategy their engine control system can use. It may be they have a coolant sensor somewhere in the system as well as the head system, and they use that to monitor cooling system efficiency.

Hock
08-23-2009, 09:15 PM
Which newer cars? Our sensor is in the intake manifold at a point where coolant is crossing over from the two heads on it's way towards the thermostat.

Head temp will be higher but I would suspect that if someone is putting a sensor in the head itself, it is due to some variable necessary for a strategy their engine control system can use. It may be they have a coolant sensor somewhere in the system as well as the head system, and they use that to monitor cooling system efficiency.

For instance, the 04 Mustang 3.8l, it uses only a head temp sensor for the EEC to read temp and control the fan. The gauge also gets its reading from that same sensor. There are no other temp sensor for the engine on that engine.

XR7 Dave
08-24-2009, 09:25 AM
Readings taken from the cylinder head can be more accurate, but the location chosen for the sensor should be tested. If you select a spot that doesn't get good circulation you might end up with bad readings. I suggest leaving the sensor where it is. Ford chose that location for a reason.

Modern engine management can include cylinder head temperature readings in their strategy in addition to coolant sensors, but that requires an additional sensor and wiring input to the EEC and I'm not sure if they are referring to coolant temperature at some point on the cylinder head or if they are actually measuring metal temperature. In any case, this feature is turned off in all versions of the software that I've seen.