Low ECT until pulling up hill

[Jax7151]

Ok so I have an 06 f350 and my ECT only runs about 170-175 when driving around town but climbs to 220 fairly fast when loaded. My delta is usually 7-11. I'm planning on replacing the thermostat with a new ford one as soon as I get the chance. My question is will the thermostat help keep it cooler when loaded or will that only solve the running too cold when not pulling issue?

[dannyboy950]

There is some contention on this but to me yes it will draw the delta closer together.

The coolant system is designed to be closed and to open at 195*+-. This gives the coolant time to draw absorb heat from the engine [heat exchange] Then to open and exchange the cooler coolant from the radiator to displace the heated coolant from the block then to close and start the cycle again.

With the thermo always open the coolant passes thru the block to fast to absorb the heat from the block properly. In essence a properly operateing system coolant temps will increase but droping block/oil temps by the amount of heat exchanged.

So even tho coolant temp rises oil temp drops bringing the deltas closer. How much depends on the efficiency of the heat exchange.

Hope this helps some. Just my understanding of the heat exchange process of course.

[thecaptin]

How many Miles? Could be a water pump issue

sent from phone

[Jax7151]

So at what ECT shoul I start to be worried about overheating? I've seen some say 220 and others say 230. It has 112k miles.

[Pro fuzz]

Truck will defuel around 254 IIRC (limp mode)

[Stumppy]

I was having this same issue turns out i have blown head gaskets.

[thecaptin]

Originally Posted by Stumppy

I was having this same issue turns out i have blown head gaskets.

Good Call.



OP: Are you losing any coolant? Or is it discolored?

[dannyboy950]

Ok guys how did we get from an overly cool coolant temp to a blow head gasket as a possibility. Dumping hot exhaust gases into the coolant is certainly not going to lower coolant temps. Just the opposit.

[thecaptin]

Im just curious as to the sudden change in ECT temps In relation to load.

[dannyboy950]

With the engine and transmission both working harder it is generateing more heat with out a corresponding increase in cooling/heat exchange, you begin retaining residual heat eventually. As best I can remember from the course on heat exchange. LOL been a long time since that class tho.