no1dc
Jan 13th, 06, 02:00 PM
I'm at my wits end. Quick History; bought 1970 2dr coupe malibu, 350, 350th auto in 2001, drove home from New Mexico watching gauge, 190* on highway and 215-225* at stop lights/traffic. When we stared home I had to add antifreeze and water. Found the bottom hose outlet to be leaking where it joined the radiator(steaming out under pressure) when we got the car home. Figured that was the reason for the need to add coolant/water when we first started. We hit two deer driving it home and have been rehabing the 70 since.
I replaced the radiator with an aluminum one(p30 step van one), new hoses, original functioning clutch fan, new 15lb radiator cap, stock fan shroud(for now plan on putting the electric fans on this spring, who knows now maybe sooner), new heater core. The intake was taken off and resealed by my friend the mechanic as the previous owner used the rubber gaskets and they were weeping at the corners. For the past two weeks everything seemed to be fine. Son and I drove it around town and some highway and it stayed at 190*.
Fast forward to today. Seemed to be running fine temp wise. Took it on the highway and noticed the kickdown didn't seem to work(it didn't work as I recall when we bought it). I adjusted the cable and can get it to kick down below 40mph but not above, is that normal? Anyway back to the overheating or at least that's what the mechanical gauge says(the sender is in the passenger head and I do have headman headers). It shot up to 250+* after several attempts to get the kickdown to engage(floored the car several times). Come back into town and the temp drops dramatically, turn the heater on and it drops more.
Went to see my friend the mechanic and when we took the cap off the coolant level was low, about 3". I know it was filled properly two weeks ago and even saw the level drop when the thermostat opened and I filled it. I installed and overflow tank with the new radiator as well as approrpriate new 15lb cap. We top it off I take it out and it does the same thing. They recommend I replace the thermostat. Took the "old" one out, it was a 160* and installed a new NAPA premium one, 180*. Button it all up and now it stays at 210-215 at idle vs 190 previously. Think it might have air in it so take it for a short test drive and it climbs to 240 before I turn the heater on, temp drops, and I head home, turn off check coolant level and it's right at the filler neck.
After I installed the new thermostat I left the cap off waiting for it to warm up and the level to drop(thermostat open). I kept an eye on the gauge it went to 230* and the coolant level actually raised up so I put the cap on, turned the heater on and the temp dropped to 200*. I did feel the top hose and it was warm yet the bottom hose didn't feel warm at all, especially compared to the top hose.
I will say the car sat with antifreeze in the block only for a couple of years as the radiator had been removed so I could rebuild the front end, etc...
The water pump that is on there now was replaced a couple of years before we bought the car by the previous owner, there was a receipt I saw but have since misplaced. Is it possible that the water pump is bad? It is the ONLY thing in the cooling system I haven't replaced. I'm thinking about replacing it this weekend.
On initial startup there is "water" out the exhaust but seems to go away after warm up. I don't smell antifreeze coming out the exhaust but do wonder if the head gaskets are leaking. That would explain the coolant drop I mentioned earlier. The previous owner supposedly "rebuilt' the top end when he installed the current cam he put in it along with Pete Jackson gear drives. Based on some of the other work I'm skeptical but then again it drove fine on the highway the day we bought it 5 years ago.
I realize this is a lot of info but wanted to give you an accurate description of what is going on and what's been done to the best of my knowledge.
One last thing. I'm thinking of moving the temp gauge sender to the bung in my thermostat housing(replaced the stock one today when I put in the new thermostat, preparing for the electric fan install) and putting my lower rated temp sensor for my electric fans in the passenger head, and putting my higher rated sensor in the intake) good idea or don't really need to mess with it? Thanks for your patience and any help.
I replaced the radiator with an aluminum one(p30 step van one), new hoses, original functioning clutch fan, new 15lb radiator cap, stock fan shroud(for now plan on putting the electric fans on this spring, who knows now maybe sooner), new heater core. The intake was taken off and resealed by my friend the mechanic as the previous owner used the rubber gaskets and they were weeping at the corners. For the past two weeks everything seemed to be fine. Son and I drove it around town and some highway and it stayed at 190*.
Fast forward to today. Seemed to be running fine temp wise. Took it on the highway and noticed the kickdown didn't seem to work(it didn't work as I recall when we bought it). I adjusted the cable and can get it to kick down below 40mph but not above, is that normal? Anyway back to the overheating or at least that's what the mechanical gauge says(the sender is in the passenger head and I do have headman headers). It shot up to 250+* after several attempts to get the kickdown to engage(floored the car several times). Come back into town and the temp drops dramatically, turn the heater on and it drops more.
Went to see my friend the mechanic and when we took the cap off the coolant level was low, about 3". I know it was filled properly two weeks ago and even saw the level drop when the thermostat opened and I filled it. I installed and overflow tank with the new radiator as well as approrpriate new 15lb cap. We top it off I take it out and it does the same thing. They recommend I replace the thermostat. Took the "old" one out, it was a 160* and installed a new NAPA premium one, 180*. Button it all up and now it stays at 210-215 at idle vs 190 previously. Think it might have air in it so take it for a short test drive and it climbs to 240 before I turn the heater on, temp drops, and I head home, turn off check coolant level and it's right at the filler neck.
After I installed the new thermostat I left the cap off waiting for it to warm up and the level to drop(thermostat open). I kept an eye on the gauge it went to 230* and the coolant level actually raised up so I put the cap on, turned the heater on and the temp dropped to 200*. I did feel the top hose and it was warm yet the bottom hose didn't feel warm at all, especially compared to the top hose.
I will say the car sat with antifreeze in the block only for a couple of years as the radiator had been removed so I could rebuild the front end, etc...
The water pump that is on there now was replaced a couple of years before we bought the car by the previous owner, there was a receipt I saw but have since misplaced. Is it possible that the water pump is bad? It is the ONLY thing in the cooling system I haven't replaced. I'm thinking about replacing it this weekend.
On initial startup there is "water" out the exhaust but seems to go away after warm up. I don't smell antifreeze coming out the exhaust but do wonder if the head gaskets are leaking. That would explain the coolant drop I mentioned earlier. The previous owner supposedly "rebuilt' the top end when he installed the current cam he put in it along with Pete Jackson gear drives. Based on some of the other work I'm skeptical but then again it drove fine on the highway the day we bought it 5 years ago.
I realize this is a lot of info but wanted to give you an accurate description of what is going on and what's been done to the best of my knowledge.
One last thing. I'm thinking of moving the temp gauge sender to the bung in my thermostat housing(replaced the stock one today when I put in the new thermostat, preparing for the electric fan install) and putting my lower rated temp sensor for my electric fans in the passenger head, and putting my higher rated sensor in the intake) good idea or don't really need to mess with it? Thanks for your patience and any help.