Running hot - need some help

[Chryco Psycho]

Honestly in this case a shroud will not help , , shrouds only help when the car is not moving or moving slowly as speed increases the air flow through the rad is fine & the fan is not adding anything , if you go to a larger rad you also have the problem of the small block using a right side lower hose & the big block using left side in most cases unless you use the later model pump housing .
 The belt being loose can definatly cause problems it could be slipping under the load & slowing water pump speed so I would fix that first .
 When you say timing was set correctly , to what factory spec ? I tend to disconnect or use an allen wrench & limit the vacuum advance curve then set timing at idle around 12* with total around 36* @ 3000 rpm , this alone could be causing overheating while driving , make sure the vacuum advance is connected to port vacuum not manifold , if you are still using it , port vacuum is zero @ idle increasing with RPM , Manifold vacuum is opposite hig @ idle & dropping with rpm , if it is connected wrong that will causing heating also . Adding a spring or even just a coiled coat hanger inside the hose can eliminate the lower hose collapsing

[dave73chally]

Replaced the alternator belt, not the issue. Tested the sensor and wiring and don't believe the gauge or sensor are at fault. When the car is cold and ignition turned to power accessory, the gauge reads directly in the middle. With the car still in accessory, I unplugged the connector to the sensor and it fell to zero. Correct me if I'm wrong, but isn't this the way the gauge and sensor are supposed to be working?

Still have not had a chance to borrow a temp gun so I don't know the true temperature. That all being said, I drove about a mile to get gas and car ran hotter than normal on the gauge reading but nothing outrageous. Powered down to get fuel and on initial startup the gauge flew all the way over to hottest level possible. What is going on?? Maybe truly is a faulty gauge? 

[Chryco Psycho]

with the engine cold the gauge should not move in acc , unplugging the sender the gauge has no ground so it should drop to zero though , sounds like a bad sensor or gauge

[dave73chally]

Thanks for the clarification Chryco, so in ACC the gauge should not move? Does it matter that in ACC all of my gauges move?

I'll try to get a temp gauge to mount under my dash until the dash comes out over the winter. Is wiring up a new gauge as simple as wiring a ground, tapping into the existing sensor wire and the ignition switch?

[dodj]

Thanks for the clarification Chryco, so in ACC the gauge should not move? Does it matter that in ACC all of my gauges move?

I'll try to get a temp gauge to mount under my dash until the dash comes out over the winter. Is wiring up a new gauge as simple as wiring a ground, tapping into the existing sensor wire and the ignition switch?

They will move in ACC, CP just said if the engine was cold, it would not move.

unplugged the connector to the sensor and it fell to zero. Correct me if I'm wrong, but isn't this the way the gauge and sensor are supposed to be working?

That should happen. Without the ability to flow current (you've opened the cct - removed the gnd as CP said) the factory gauge will go to the resting position (ign off position). Your gauge seems ok, if your engine temps are actually ok it is probably a faulty sensor.
If your temps are actually high, then rad t-stat or water pump. It's a new t-stat so if the pump isn't making any noise, my guess would be rad. You could remove the t-stat and put in a pot of boiling water and confirm that it is opening fully. I've had a large number of new t-stats not function properly. 

[dave73chally]

Thanks dodj. The thermostat and sensor are both new, I'll pull both and test. The water pump isn't making any noise or leaking so I'm assuming that's not the issue either. I'll try to get a temp gun and get an accurate reading, that seems like the best thing to do now.

While the thermostat is removed, would it be worthwhile to drill a couple holes like some people do?

[dodj]

I've never drilled a hole in the t-stat. I think it is mainly for filling the cooling system and letting air through the t-stat while you fill? Up to you I guess.
If you are testing the temp sensor, the resistance drops as it heats up. I think it starts off cold at about 80-90 ohms and drops to about 10-20 ohms when hot.

[Chryco Psycho]

I usually put 1 small hole in the T stat , no big deal either way but it will stop air getting trapped under it .

[dfrazz]

Thanks dodj. The thermostat and sensor are both new, I'll pull both and test. The water pump isn't making any noise or leaking so I'm assuming that's not the issue either. I'll try to get a temp gun and get an accurate reading, that seems like the best thing to do now.

While the thermostat is removed, would it be worthwhile to drill a couple holes like some people do?

Sorry for brining up an old thread but wondering if you ever found the problem Dave?  Did you get any temp readings?

[dave73chally]

I put 1 small hole in the thermostat and tightened up the alternator belt, changed the water pump. Still was having some issues so I tweaked the timing and it all seemed to go away. My temp gun reads 200 at the max and creeps up a bit when standing still on a hot day but cools down quickly when moving. All in all haven't had any issues since.