Overheating Issues - Water Pump?

Discussion in 'Fox 5.0 Mustang Tech' started by Dan Benavides, Jun 26, 2017.

  1. Hello,
    Let me start by saying that I am new to the domestic car scene and this is my first fox body mustang. I purchased the car in the winter time and drove it around town without any overheating issues. As the weather got hotter so did the car. I've decided to change the following.

    1. New Aluminum 3 row radiator
    2. New Aluminum shroud and two electric fans
    3. New darhle electric fan controller.
    4. New 180 thromostat and water neck
    5. New upper and lower radiator hoses
    6. New water pump hoses

    After all this I burped the systems and the car is still running hot, around 230 degrees. Fans kick on around 200 degrees but do not help. The radiator is boiling over and spilling into the catch can.

    The only thing I haven't changes is the water pump, no signs of any water leaking from the holes or waterpump. I've crawed under the car and checked.

    Could the waterpump be failing? I ordered an new GMB water pump that flows more then the stock one. Has anyone experienced this before?
  2. Ok, need some specific information
    Year, miles, modifications, engine size, trans type, you know, trivial stuff like that :stick:, oil look good?
  3. 1990 LX with 69k Miles and c4 automatic trans. Stock 5.0 bottom end with holley heads, Holley intake and e303 cam.

    I bought the car with those engine mods.

    Oil has always been clean and no white smoke. I will pull the plugs today to see if they are wet but no signs of a blow head gasket.

    When I burp the system I do see the water running through the fins but very slow which leads me to believe it's the water pump

  4. And make sure that thermostat is opening up.
  5. Pulled 4 plugs two from each side and they don't look wet, there some oil on the threads but the tips are dry. Cleaned the threads and it's definitely oil and not coolant.
  6. what fans and how many cfm's are they rated for
    are they puller or pusher fans
    Does the car overheat in city traffic or at highway speed
  7. Underdrive pulleys?

    Was the alternator upgraded before you added electric fans?
    Davedacarpainter likes this.
  8. Which way is the water flowing through the radiator? How is the belt routed? The flat non-ribbed side of the belt is what should be riding on the pulley. It's possible the belt is routed incorrectly, and if the ribbed side is driving the pump pulley, it's driving it backwards. If it's routed correctly, it's possible (not likely, but possible), that an older standard-rotation water pump was installed on it. These engines require a "reverse-rotation" pump. Also, do you see any bubbles or smell any exhaust thorugh the open radiator cap once the car is warmed up and the thermostat is open?
  9. MFE92,
    You bring up a very good point. I will double check the belt installation and rotation this weekend. I've been out on vacation and will resume work on the car this weekend. I did replace all spark plugs, wires, and cap/rotor on the car as the plug wires where toasted since the car was running hot. I used Ford OEM spark plugs, Taylor 8mm wires, and a Taylor cap/rotor. I don't know when was the last time the car had a tune up so I replaced all the times listed for good measure. Car fired up right always and ran good. I immediately shut it down so that it wouldn't run hot.

    You bring up a good point about routing of the belt. I will double check it as soon as I get a chance. I also already purchased a new reverse rotation water pump and gasket. I suspect the water pump is not flowing enough coolant through the radiator as I see very little flow through it when I burp the system.

    Thanks for your help! I'll keep you posted!
  10. Does anyone know if I must change the timing cover gasket when I replace the water pump? I don't see any signs of the timing cover gasket leaking. Should I just do it for good measure? What is everyone's experience with this?

  11. No need to if nothing is leaking
    Shakerhood likes this.
  12. That depends on how long it has been there and if there was any corrosion built up on the bolts, if the bolts came out clean I would probably leave it alone but if the bolts where all corroded it would pay to change them out.
    Use anti seize on the bolt threads and shaft when you put it back together.
  13. Just a thought, check to make sure you have the correct timing cover for the reverse rotation water pump, if it does not have the mechanical fuel pump opening your good, I think. Compare your timing cover to one line,
  14. ok I will do that, I did buy a new bolt kit from LMR so that all the bolts are new. I will use anti seize as well.

  15. Sounds like a good Idea to check the cover while I got the pump out. Is there any photo of what the cover should look like? I know mine has EFI and an upgraded pump in the tank. So there shouldn't be a mechanical fuel pump opening.

    Thanks again!
  16. FTI-SBF Timing Cover -EFI
    Just make sure the ramps for the flow into the engine are the same orientation
  17. Water pumps almost never just stop flowing like they should. If they go, they'll usually piss coolant out the weep hole. But if you're bound an determined to change it, just be VERY careful because some of those bolts like to seize and break off in the timing cover. So if any of them give me any grief at all, I turn around and break them loose by tightening them, which is actually the lowest-stress way to break loose a stuck bolt.
  18. Before replacing the thermostat, It's always a good idea to "back-flush" the cooling system. I usually pull the thermostat, disconnect the inlet hose to the radiator, and run a garden hose into the thermostat housing and just flush out the system which will remove any blockages or loose junk floating around in the cooling system.
  19. Ok guys I'm stumped! I replaced the water pump, timing cover, & bolts. Put everything back together and burped the system. The car is still overheating. Thermostat seems to be opening up and coolant is flowing thru the radiator.
    I have noticed that both upper and lower radiator hoses have allot of pressure. Is this normal? What am I missing ?

  20. Explain a lot of pressure, 16lbs is not a lot of pressure, you should be able to squish the upper hose with the cap on and system hot, engine running. Start by pulling you t-stat and test it in a pot of water on the stove, a meat temp gauge will work, just don't tell your significant other what your doing, some frown on using kitchen tools around automotive parts.
    If your t-stat checks out have your radiator checked out.
    This is contingent on other parts of your cooling system operating correctly
    imp likes this.