[goatcheese]

I have the same exact symptoms going on. I also used an IR themometer with the same results. I have an aluminum radiator with electric fans, checked the water pump clearances, etc.
I bought a new water pump (PWP381) from cardone that's supposed to have an improved impeller. I was gonna install it tonight but, looks like I better check my timing instead. What's funny about mine is it ran cool for the first 75 miles or so then overheated. It now will overheat while idling or driving only a mile or so. The distributor is tight so I know it didn't move. I will check it this evening.

[jray1]

Originally Posted by goatcheese

I have the same exact symptoms going on. I also used an IR themometer with the same results. I have an aluminum radiator with electric fans, checked the water pump clearances, etc.
I bought a new water pump (PWP381) from cardone that's supposed to have an improved impeller. I was gonna install it tonight but, looks like I better check my timing instead. What's funny about mine is it ran cool for the first 75 miles or so then overheated. It now will overheat while idling or driving only a mile or so. The distributor is tight so I know it didn't move. I will check it this evening.

The problem with mines so far seemed to be the vacuum advance. The initial timing was where it needed to be but the vacuum pulled in way to much timing way to fast. I should max out at 36 degrees of timing but I was hitting 45-46 possibly more at higher rpms. Without vacuum it will max at 36 and the mechanical curve seems great for this motor so far. Also I should mention this is an HEI distributor not the points style.

[goatcheese]

I have an HEI also. Even at idle the vac advance is pulling too much? My car will overheat just idling. I thought I set my initial timing at 12 degrees but, never check what the advance was doing. I wonder if the vac advances we have are faulty? Going out to look at mine now.

[jray1]

I truely think the hei With the vacuum hooked up just advances way to fast for the motor. Try unhooking the vacuum lines and plugging the vacuum ports then set your timing around 14-16 degrees advanced. Rev it to around 2500-3000 rpms and you should be at max advance. Shouldn't go past 36 degrees advance.

[goatcheese]

Well.... I thought I had the vac advance problem. I had about 8 degrees initial and when plugging vac advance in it looked like it went to over 40 degrees advanced at idle! I have an adjustable vac advance canister so I backed it all the way out. I adjusted my initial to about 12-13 and adjusted the vac advance to add another 12 or so. After that I adjusted my air/fuel and idle on my carb. Done all this in 5-10 minutes while keeping an eye on my temp. It still crept up to 230 in that short period of time . I borrowed a hydrocarbon tested from a friend tonight to test my coolant. Afraid I have the head gasket issue. Makes sense because my setup ran for hours three or 4 times but, since I drove it for an hour and it got hot it overheats within 5-10 minutes idling. Even faster while driving...

[rexs73gto]

Sorry to hear , I hope though now you can get it fixed & have no more problems once it gets fixed. None of us ever like to hear of any of us having any problems with our toys but at least now it has a possible end. If there is any thing we can help with in the future drop a line & some one here will be glad to help.

[jray1]

Originally Posted by goatcheese

Well.... I thought I had the vac advance problem. I had about 8 degrees initial and when plugging vac advance in it looked like it went to over 40 degrees advanced at idle! I have an adjustable vac advance canister so I backed it all the way out. I adjusted my initial to about 12-13 and adjusted the vac advance to add another 12 or so. After that I adjusted my air/fuel and idle on my carb. Done all this in 5-10 minutes while keeping an eye on my temp. It still crept up to 230 in that short period of time . I borrowed a hydrocarbon tested from a friend tonight to test my coolant. Afraid I have the head gasket issue. Makes sense because my setup ran for hours three or 4 times but, since I drove it for an hour and it got hot it overheats within 5-10 minutes idling. Even faster while driving...

Sorry to hear that, after getting some more time to check mine yesterday I am not totally out of the woods either. Mine is running way cooler now it takes a long time for the temp to get up but it wants to go to 200-205 and stay there. Since I have a 160 thermostat I am wondering now if there is a flow issue as well.

[72LuxuryLeMansLa.]

Originally Posted by jray1

Sorry to hear that, after getting some more time to check mine yesterday I am not totally out of the woods either. Mine is running way cooler now it takes a long time for the temp to get up but it wants to go to 200-205 and stay there. Since I have a 160 thermostat I am wondering now if there is a flow issue as well.

I suspect you have the same deal as a bunch of guys, there are a few different issues contributing to your higher than desired temps. Notice I said higher than desired and not over heating. Some guys find a few degrees here and there by going through everything that can cause higher temps. They find dragging brakes, timing and fuel mixture issues, a few thousandths off on water pump plate clearance, radiator is dirty, plugged or wrong model for the application, bad fan clutch, wrong clutch or fan, fan incorrect distance from radiator, no shroud, wrong or incorrect fitting of shroud, or wrong amount of fan in and out of shroud................... I'm tired of typing!

Karl