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  • #16
    Thanks OVERLOADED, I hadn't thought of that yet.

    I have re-installed the electric fan as it obviously is not the problem and the power gain is liked very much. I have discovered another way to buplicate the overheating problem though. If I run the engine at cruising RPM's (2500-3000) while not moving, I can get the engine temp to rise just like it does while I'm pulling a grade / hill. I understand that there is not the same amount of airflow moving across the radiator but the engine temp reacts very similar to while I'm on the highway grades. My question to you is this, why does the engine react the same standing still as it does while pulling grades or am I right about the radiator airflow? If I drive the ol' girl on level to semi-level ground on the freeway her temps stay just fine but it's as soon as I start up those long hills, with my foot heading towards the floor, that she starts getting hot. Everything in the coolant system is stock except for the aluminum radiator. I'm pulling my hair out here, haha! As always, thanks for the inputs!

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    • #17
      Side Note: Have you seen that sticker that reads : "If I wanted a Hummer, I'd ask your wife" ? Haha, I wish my girlfriend would let me put that one on my Jeep!

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      • #18
        Originally posted by OVERLOADED View Post
        I've heard if a head is shaved to much when it's reworked it will cause the motor to run hot. It could be as simple as a head gasket not matching the port holes on the head, restricting water flow. which wouldn't be a problem until in a bind.
        If the head is decked it increases compression ratio which in turn can add to preignition issues which ..... you get the idea.

        I would personally machine an inline aluminum piece (to add to one of the hoses) which i could then add a seperate temp sensor and a seperate guage. I have had an overheating issue turned out to be a bad OEM sensor before. The replacement acted up within 2 weeks after replacement. The next one has been golden. Also look into a rad cap with a guage integrated. All of this assumes fualty readings. You haven't mentioned if it spews coolant (could be a bad rad cap which i also had a ***** tracking).

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        • #19
          No coolant has ever purged the system but the temp sensors very well could be F'ed up in some way. I may be relying on the dealer inspection of the sensor a little too much. I will be replacing the coolant temp sensor on the thermostat housing and I have already replaced the gauge temp sensor when I did the motor (I broke that little guy off on the firewall while taking the motor out, haha!) Thanks!

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          • #20
            Does your Mean Green alternator wine like a supercharger? Mine seems to do it at low RPM's in the first minutes after start up? Just wondering. I think it might have something to do with it charging the system. Thanks!

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            • #21
              If the engine has a load, like climbing a hill, temps will naturally go up. A 20 degree climb isn't unusual.
              If the temps drop as soon as you top the hill and the temps are steady going up the hill (but just high) then you rad looks to be of sufficient size to dump the heat out.
              An auto tranny with an unlocked torque converter can generate heat and going uphill would be a condition that would unlock it -assuming it's all hooked back up properly after the motor swap. But if you have a manual this wouldn't matter and standing still and revving it wouldn't generate heat either.
              Based on my experience with a clogged cat it didn't have any effect on temps, just hiway power - max speed was about 50mph.

              But now you state the temps rise with revs, no load. What changes? Vaccuum, timing and speed of the waterpump.
              With no load vac shouldn't change that much - so egr, vac timing, MAF/MAP would all read 'normal' and shouldn't do anything to raise temps.
              Mech advance timing would increase with revs, but again, at rest I wouldn't think that would cause a temp rise issue unless your timing is way off. Do you ever hear pinging? Higher compression means you may need higher octane gas, which would actually run cooler.

              The waterpump will spin faster - and possibly cavitate and flow less water OR spin so fast and move so much water as it neverspends enough time in the rad to dump the heat. I assume the pump is good and spinning the proper direction.

              I have a 305 chevy in my 90 that the previous owner installed and iv'e been dealing with heat issues but finally got it sorted out. EGR, trans cooler, wet water additive, cooler plugs, timing tweaks, hi-flow thermostat (see summit - they're great, i mean summit and the thermostat) - a bigger rad ended up being the best solution. The stock (4 cyl) rad they left in there would work until a hi-load or 90+ day and then temps would rise and sit around 230.
              Last edited by prof_fate; 06-26-2009, 10:31 AM.

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