Just wondering where to start. Car was running fine drove it three hours straight no issues. Rebuilt the carb car runs way better. Now the temp gauge goes past the half point. Could it be a thermostat? I just got done putting in a fan shroud. This is the stock 22" radiator.
Cooling issues
- Thread starter ArcDevilz
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69hemibeep
Sponge Bob Square Wheels
It might be building heat from a lean condition. Doe's it heat at idle or cruise? Did he rejet or change metering rods?ArcDevilz said:
mcmopar
Well-Known Member
^^Bob, you beat me to it by a whisker^^
Agreed, it may be that the carb is running leaner than before. Prior to the rebuild the carb could have been a bit on the rich side but now that it has been rebuilt the air/fuel ratio may be a bit leaner. Proper air/fuel ratio for 1969 was 14.4 parts air to one part fuel. If it were running richer than that temps would have been down. If it has been leaned out the engine will run a bit hotter. If I remember correctly the proper idle mixture screw (which controls a/f ratio) setting on the AVS was 3-1/2 turns out from fully seated (screwed all the way in). You might want to check with your carb man and see where he set the idle mixture screw and if he changed either the jetting or the metering rods to a larger diameter. If he did not change jets or metering rods I'd say its running just about right. In all actuality if your temp gauge reads correctly (mine doesn't) a little past half is just fine for a normal operating temperature. I'd start getting concerned if it was pegging at 3/4 of the way up, though.
Agreed, it may be that the carb is running leaner than before. Prior to the rebuild the carb could have been a bit on the rich side but now that it has been rebuilt the air/fuel ratio may be a bit leaner. Proper air/fuel ratio for 1969 was 14.4 parts air to one part fuel. If it were running richer than that temps would have been down. If it has been leaned out the engine will run a bit hotter. If I remember correctly the proper idle mixture screw (which controls a/f ratio) setting on the AVS was 3-1/2 turns out from fully seated (screwed all the way in). You might want to check with your carb man and see where he set the idle mixture screw and if he changed either the jetting or the metering rods to a larger diameter. If he did not change jets or metering rods I'd say its running just about right. In all actuality if your temp gauge reads correctly (mine doesn't) a little past half is just fine for a normal operating temperature. I'd start getting concerned if it was pegging at 3/4 of the way up, though.
george68hemirr
I think you guys are full of shit.
you guys hit right on the head....what they said 
I think I was having issues before the carb rebuild. I would drive the car and the radiator would overflow. I changed the thermostat an hour ago and still had issues. I am going to ask the carb shop about the jets and what he did to the carb in the morning. I am hearing a bit of a bearing noise coming from the water pump as well. I think the timing might also be a bit to advanced. I think I will start with the carb and timing and then check the water pump.
I had the car idling with the radiator cap off and I could never see any flow. Usually you can rev the engine bit and see the movement in the flow. This was while the car was to temp. It did seem like the thermostat opened. It seemed to me that the bearing noise kicked in after a few minutes and would change pitch.
I had the car idling with the radiator cap off and I could never see any flow. Usually you can rev the engine bit and see the movement in the flow. This was while the car was to temp. It did seem like the thermostat opened. It seemed to me that the bearing noise kicked in after a few minutes and would change pitch.
george68hemirr
I think you guys are full of shit.
when i change a thermostat i usually drill 2- 1/8 holes opoisite each other in the thermostat so i can get all the air out of the system and also jack the car up on the side the radiator fill is to also release all the air in the system....fill it and watch for bubbles....when they are gone then you are good......back to the thermostat....i usually boil some water in a pot and drop the thermostat in to check if the thermostat opens when hot.....sometime you get bad ones that are new 
Jim S.
Well-Known Member
My goofy temp gauge is just "wishful thinking" when it comes to accuracy. It usually goes to 3/4 after driving and idling for 5 mins. laser thermometer says I'm about 185 near the temp sensor with no hot or cold spots on the radiator. I would get back to where you were before the carb work and start from there. I do the 1/8" hole thing also in the thermostat housing. Great advice about jacking the car up to "burb" it. Never thought of that. Also that Water Wetter stuff really showed minimal difference on the laser thermometer.
Big John
Sit back, relax Don't bitch about the cigar smoke
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I'd put a new 160 degree thermostat in with the holes drilled as George said and change the water pump. Then make sure the lower hose is not collapsing. Some replacements did not have the inner "spring" in them to stop that. Do a pressure test on the system including the cap.
I'd also check the temp of the engine with a thermometer in the top of the radiator.
I'd also check the temp of the engine with a thermometer in the top of the radiator.
moparstuart
Well-Known Member
they also have temp guns that are pretty cheap now .Big John said:
Big John
Sit back, relax Don't bitch about the cigar smoke
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moparstuart said:
Yea, but the temp gun really only measures surface temperature. Its a good indication, but you can't beat a simple thermometer.
Of course, then you've got the inaccuracy of the infared temp gun... especially the cheap ones. There's a lot of variables with surfaces that will affect a good measurement.
george68hemirr
I think you guys are full of shit.
great advice big.....i forgot about the collapsing of the hose.....i had that problem also without the spring inside the hose
I pull the thermostat again. Drilled the two 1/8 inch holes. Changed the water pump. Got everything together except for the radiator. I am going to send it out in the morning to get checked out for blockage or anything abnormal. It looks as it has been re cored to a three row. Hopefully this should eliminate any issues with the cooling system. After this I will be taking the car down to get tuned and timed. One thing I noticed is that the car had the original water pump not an aftermarket deal. T seemed fine nothing loose,no leaks. Is there anyone who can rebuild these originals? What else should I look for? It seems like I have covered all my bases.
Well It turns out that two things where happening here. The radiator was clogged up for starters and the cap was not holding pressure. I essentially went over the whole system and she is running nice and cool. I could not get the temp gauge to move past 1/4. The carb and timing are all set. Car is running better than when I picked her up. The only thing I am noticing is a small exhaust leak. It should be an easy fix and will knock it out over the weekend.
Thank for the help guys.
Thank for the help guys.
george68hemirr
I think you guys are full of shit.
cool.....another happy roadrunner screaming down the road