2003 5.4L recent purchase is overheating after sparkplug change.

[Lee_H]

Bought a 2003 Eddie B. with 5.4L engine for a spare vehicle. Pulled codes for miss fire, replaced sparkplugs and coils all around (Motorcraft). Ran it for a week to work, no problem. Second week started to over heat. Slowly at first but by the end of the second week barely made it to work. Ride is about 20 min. combined highway and stop n go. Replaced fan clutch and thermostat (180). Still over heating. Took old thermostat cut away valve and put back in. Still overheating (about 15 minutes to boil over). Replaced water pump (from NAPA). Left blank thermostat in. Old water pump spun but was seized in engine, took chisel to pry it out. Condition: rotor was eaten away, looked like it was attacked with acid. Cleaned and lightly coated the new pump with antiseize, no apparent leaks. Ran this morning for about half hour before it started running hot. Code reader in live data mode said 200F for a bit then climbed to 240F and then boil over at 250 plus. Running vehicle in Low 2 to increase rpm doesn't help that much. Although I bought the lower hose (in case it was collapsing) (It is really long) I don't see the lower hose failing since the over heating has it fully pressurized. Before jumping to head gaskets, is there anything I missed? It did not have heat when purchased, assumed the hot water valve failed since the truck ran with the temp. gage centered the whole time. No miss firing now, it actually runs strong and fun to drive. Did not back flush radiator since it seemed to be working at time of purchase.

 

[Adieu]

Was misfire on #2 or #3? That's a popular location for a coolant leak that seeps into spark plug wells

If so that could be the ongoing issue...maybe?

 

[CaptainKrunch]

I would want to know how much flow is actually going through the system. I haven't worked on cars at the dealership level since the 90s so I'm not sure what tools they have to determine coolant flow rate through the radiator. I'm just guessing you have a clogged up radiator and everything needs to be flushed or maybe the radiator needs to be replaced.


I don't have enough specific knowledge about this models issues with overheating so I'm not sure of other unique things that would cause overheating in this model.

 

[Lee_H]

The #3 plug was misfiring and was insanely difficult to un-thread out. As a souvenir I still have the plug jammed into the socket and not worth removing since the socket is stretched out in the hex area. Cleaned with compressed air and ran one of the other used plugs to clear the threads. Coated the new plug threads with anti-seize and coated the seal with LockTite 246 (med. high temp.) to stop it from backing out. I did have to remove the heater supply hose in order to gain access, but I filled the overflow and idled the engine with the cap off to de-gas.
This was OK for a week (five days) of driving before anything showed up bad.

 

[Hamfisted]

If the old water pump was in that bad a shape you can bet the inside of the radiator is just like it. Since you've done so much to get it running right I would throw in a new radiator just to cover it's base. It's the main ingredient to cooling the motor. Put the normal thermostat back in place as well. The thermostat controls the waterflow through the system. Slowing it while it's in the radiator so it has a chance to heat exchange. If you run an open system ( the system is not designed for that...) you don't give the coolant enough time in the radiator to effectively get rid of the heat. It also affects the way the computer runs the motor. Also I would recommend only Motorcraft Gold or Zerex G-05 coolant. Not the green crap.

 

[TomB985]

If the old water pump was in that bad a shape you can bet the inside of the radiator is just like it. Since you've done so much to get it running right I would throw in a new radiator just to cover it's base. It's the main ingredient to cooling the motor. Put the normal thermostat back in place as well. The thermostat controls the waterflow through the system. Slowing it while it's in the radiator so it has a chance to heat exchange. If you run an open system ( the system is not designed for that...) you don't give the coolant enough time in the radiator to effectively get rid of the heat. It also affects the way the computer runs the motor. Also I would recommend only Motorcraft Gold or Zerex G-05 coolant. Not the green crap.

Completely agree that the radiator is a likely cause. Sounds like the OP bought one that was neglected for years, and there may be a blockage somewhere preventing proper flow through the radiator. I would pull the radiator hoses and get a good look inside, but the water pump was that bad we all know what he will find.

Running without a thermostat is bad, but that is an old myth about slowing water flow down for heat exchange. If that were the case, it would also be running too fast through the engine and the coolant would never come up the temperature, and the engine would cook itself. Thermodynamics don't work like that, and running without a thermostat cannot cause an overheat by itself. Thermostats are there for a reason, though, and running under temperature can cause serious problems over the long term.

http://www.pirate4x4.com/tech/billavista/Cooling/#Myths

 

[Lee_H]

Purchased new radiator at a chain store, I' ll see what happens on the weekend. The thermostat valve being cut was more for getting the air burped out faster (more water flow) than to control the over heating. Since the only change to the cooling system was me pulling the heater supply hose out to get to the coils and plugs, air was the original thought as to the reason the thing was over heating. Since it got worse instead of better something else was going on. The fan clutch (both old and new) seem to have a lot of slip for driving the fan. Any thoughts on re-visiting the seventies (like my now gone 1971 Mustang) and locking the fan to the water pump (like the 351C two barrel did)???

 

[TomB985]

Purchased new radiator at a chain store, I' ll see what happens on the weekend. The thermostat valve being cut was more for getting the air burped out faster (more water flow) than to control the over heating. Since the only change to the cooling system was me pulling the heater supply hose out to get to the coils and plugs, air was the original thought as to the reason the thing was over heating. Since it got worse instead of better something else was going on. The fan clutch (both old and new) seem to have a lot of slip for driving the fan. Any thoughts on re-visiting the seventies (like my now gone 1971 Mustang) and locking the fan to the water pump (like the 351C two barrel did)???

Wouldn't help a thing. If that were the source of your problem, every Expedition would have been overheating on dealer lots due to a faulty design. But they don't.

A few years ago I was trying to save money while my wife is in nursing school. I was playing a game to see how efficient I could get my old 97 Lincoln town car, so I removed the mechanical cooling fan altogether. It had an electric fan that would cycle on a 230°, and I read a manual switch to cycle it earlier than that and monitored with an OBD gauge. I almost never needed to turn that fan on; even at low speeds in hot weather there was enough air going to the radiator to cool that 4.6l V8 below 210°.

The fan clutch is not your problem. Locking the fan to the pulley would just decrease your efficiency and you would still have an overheat to fix.

 

[Lee_H]

This is the current connections to the bottom of the radiator:

 

[Lee_H]

I posted what is under my truck at the moment, I can't seem to separate the fitting from the tube part. What is on the new radiator is the fitting with no tube. Yet I tried two types of "tools" to separate the fitting from the tube but the design is all wrong. I tried slipping in thin flashing to separate and this is a no go. The distance between the tube and the fitting is too close to work with. I'm used to working with a flared of the tube and a SAE threaded fitting. Is my only option to try and thread in the old fittings to the new radiator? The past person really hated the tube that existed and tried to replace it with hose. The fittings inside the old radiator seems to be loose (can move in but not rotate), if I replace the new fittings will I have a leak point?