Major problems, plz help

Discussion in 'Trucks and Trailers' started by nolucktruck, May 14, 2000.

  1. nolucktruck

    nolucktruck LawnSite Member
    Messages: 4

    I recently purchases a GM 350 crate motor (pre 1986) and stuffed it into my Landcruiser. I have absolutely no water flow through the block. I had a doner monte carlo that I used for all my bracketry so I put the water pump from it onto the new crate plant. When it had heating problems (right off idle) I replaced the pump with a new unit (spec'd for a 78 Monte Carlo). Now I still am not getting any flow. It's a new radiator, cap, hoses with no obstructions. I even took the thermostat completely out and I still had no flow. I can squeeze the upper hose when it's idling and there's no back pressure. Could it really be two bad pumps? There's no leaks on the new one. I'm using an Edelbrock performer intake. Am I missing the obvious here folks? Is this pump reverse flow or something from a 78 Monte? The pump is turning clockwise. Please help me..I'm passed my wits end! <p><p>
  2. chevy4ever

    chevy4ever LawnSite Member
    Messages: 8

    First of all, are you sure the radiator is full? I know, I know thats probably the first thing you checked. After driving nothing but chevy trucks with short block 350s for the last 21 years and rebuilding several, that you can fill the radiator full, put the cap on, let it run for ten minutes, and when you take the cap back off there is no water visible in the radiator. It really doesnt matter whether its running or not if the cap is not on. In other words make sure the radiator is full. Also, if its not full, it would take awhile to build up any back pressure. Another question, is the hose getting hot while you hold it? If it is, you have circulation. The next thing to do is take the radiator in and have it reverse flushed. Last but not least, is the waterpump drivebelt tight? If you go through all of these checks, your problem should be solved. Good Luck.<p>----------<br>A Cut Above<br>
  3. yortengel

    yortengel LawnSite Member
    Messages: 216

    Do you have coolant in the thermostat housing? Or is it dry. Just maybe you have the intake gaskets installed incorrectly. Just a thought. The cooling systems for these engines are pretty strait forward. You might use compressed air to make sure that all the passages in the intake and heads are clear. Maybe you got bad manifold. Keep use informed. And Good Luck.
  4. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    do you have the spring in the lower hose?it is not likely,but possible for the lower hose to be colapsing and preventing flow.I have never heard of anything like your situation before,and I have done 100's of motor swaps and R&R's.It sounds airbound,but the T-stat being out should fix that. Is the heater core fitting in the intake manifold,water pump or does it return to the radiator?.if you pull off the heater hose while its idling,does it shoot water out or nothing?you may be routing most of the water thru heater core,instead of rad,pinch off heater hose with clamp and see if the water starts to flow thru the rad.Any chance you left the plastic plug on the new Rad ,forgot it maybe,then slid the lower hose on and no flow?<p>----------<br>John D<br>
  5. nolucktruck

    nolucktruck LawnSite Member
    Messages: 4

    OKAY!!! It's working now. I imagine that some silicone got smashed into the water ports when I installed the I-manifold, but after messing with it for a now is pumping pretty well. Thanks for all the help!~

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