I changed my thermostat in my 97 f150 5.4 and now the truck is running funny missing chugging and loss of power and friend said it was coolant fouling out a plug or two but not sure any help would be greatful on if this is the problem and how to fix thank you.

 

Reason you changed the thermostat? Overheating?

 

DTC's please...Shot in the dark but if the thermostat housing is leaking coolant then perhaps some plugs are wet? DTC's please...

 

If the truck ran fine before the thermostat change, I would suspect an air bubble in the coolant system, though I don't know why that would create a miss. Does your friend actually know that coolant might be fouling the plugs? What evidence?

 

Air in the coolant, overheating, fail-safe operation.

 

Did you unplug anything while working? Did you get antifreeze on any of the electrical components? Most have an o-ring inside, but you could have fluid trapped in one of the connections.

 

Coolant ran down the head and filled the plug chambers.

So blow them out, that will happen if your not careful.

 

#1 why did you change the thermostat??
#2 did you replace it with a lower temp thermostat???

 

Thanks everyone for the help i will pull the plugs and blow out cylinders and the reason for changing the thermostat was it was stuck open and heater was not getting very warm.