Coolant By-Pass Kit

[modelageek]

I found this courtesy of Rockledge at FTE..........the first TSB is for a thumping..........I would bet that is your issue, Bad Waterpump, since it was fine for a while

http://www.ford-trucks.com/forums/2...e-fluctuation-thumping-in-cooling-system.html

 

[kimcrwbr1]

I can`t wrap my head around the power steering pump making the water pump slow down aren`t they both running off the same belt wouldn`t that mean the belt was slipping on the crank. And as far as steam the engine would have to be overheating to produce steam maybe the problem is the radiator is not able to cool the fluid going into the engine enough or the t-stat is not opening far enough. check the lower radiator hose when it is hot the temp should be alot cooler than the upper hose. I would change the water pump and t-stat and go from there. I`m a advocate on adding a flush kit in the heater hose coming from the t-stat housing and filling the coolant from there to force the air out of the upper block and heater core.

 

[gribly]

I can`t wrap my head around the power steering pump making the water pump slow down aren`t they both running off the same belt wouldn`t that mean the belt was slipping on the crank. And as far as steam the engine would have to be overheating to produce steam maybe the problem is the radiator is not able to cool the fluid going into the engine enough or the t-stat is not opening far enough. check the lower radiator hose when it is hot the temp should be alot cooler than the upper hose. I would change the water pump and t-stat and go from there. I`m a advocate on adding a flush kit in the heater hose coming from the t-stat housing and filling the coolant from there to force the air out of the upper block and heater core.

I spent a couple hours on this one myself since I couldn't wrap my head around it, either. The steam is being created near the exhaust valves according to what little I found. The stiff power steering pump really can cause the belt to slip on the crank, too.

 

[gribly]

I found this courtesy of Rockledge at FTE..........the first TSB is for a thumping..........I would bet that is your issue, Bad Waterpump, since it was fine for a while

http://www.ford-trucks.com/forums/2...e-fluctuation-thumping-in-cooling-system.html

First TSB doesn't cover his year truck, so it's a safe bet that it doesn't apply.