P-12 Tommy Posted May 20, 2009 Report Posted May 20, 2009 Maybe somebody can help me out here. I can take my P-12 out for a good run and after a little while it starts to run in the 200 degree range. Plus when I twist off the radiator cap I've got pressure. This is a non-pressure system right? Could my water distribution tube be plugged up? Puzzled??? Tom Quote
dirty dan Posted May 20, 2009 Report Posted May 20, 2009 Maybe somebody can help me out here. I can take my P-12 out for a good run and after a little while it starts to run in the 200 degree range. Plus when I twist off the radiator cap I've got pressure. This is a non-pressure system right? Could my water distribution tube be plugged up? Puzzled??? Tom Are you getting water in the oil? Sounds to me more like a blown headgasket. Quote
P-12 Tommy Posted May 20, 2009 Author Report Posted May 20, 2009 No water in the oil. The engine runs really well. Good power. Tom Quote
Plymouthy Adams Posted May 21, 2009 Report Posted May 21, 2009 blown headgasket does not always leak into the oil gallery..90% will be between cylinders and the remaining be a leak into a cooling passage allowing the cylinder pressure to be felt in pressure and superheated water..(give or take...) Quote
P-12 Tommy Posted May 21, 2009 Author Report Posted May 21, 2009 Could a bad water distribution tube cause pressure? Tom Quote
Don Coatney Posted May 21, 2009 Report Posted May 21, 2009 Could a bad water distribution tube cause pressure? Tom No. Can you post a picture of the top of your radiator? Quote
billwillard Posted May 21, 2009 Report Posted May 21, 2009 The system is non presure if you have the right cap . Do you? What thermo are you running? If you are running a 195 thermo (which you should be) 200 is ok as your guage may be off a little any way. Does it rase to 200 and no more? If so you have no troubles. Quote
P-12 Tommy Posted May 21, 2009 Author Report Posted May 21, 2009 No. Can you post a picture of the top of your radiator?Hey Don, I've got to wait till I get home tonight to take a picture. BTW, the top of the radiator has a round cup in the center with a vent line that runs across and down the side. It's the original radiator. Quote
P-12 Tommy Posted May 21, 2009 Author Report Posted May 21, 2009 The system is non presure if you have the right cap . Do you? What thermo are you running? If you are running a 195 thermo (which you should be) 200 is ok as your guage may be off a little any way. Does it rase to 200 and no more? If so you have no troubles. Hi Bill, To answer your questions: Obviously I've got to change my cap. It's a 4 lb cap. The thermo was put in before I got it. It heats up more when I'm sitting at a red light in 85 degree heat. Like I told Don, it's got a cap shaped dome on top in the middle of the radiator with a vent line running across and down the side. It's the original radiator. Tom Quote
greg g Posted May 21, 2009 Report Posted May 21, 2009 You might want to check the accuracy of the dash gauge with a thremometer in the radiator. Also keep in mind that the temp gauge sender is where the coolant will be the hottest. The cap won't matter if its the stock radiator as the over flow tube is located beneath where the cap seals. If its not plugged you should not get any pressure build up no matter what cap you are using. Check it by blowing a bit of air through the overflow tube. Couple of spiders nest will plug them. Is your fan belt tight? Is your radiator clear and flowing properly? A filled radiator should build a column of water about 6 inches high out of the lower fitting if its in good shape. Rule of thumb, hot at low speeds = air flow problem hot at highspeeds = fluid flow problem. Quote
P-12 Tommy Posted May 21, 2009 Author Report Posted May 21, 2009 (edited) :DThans for the info Greg! When I open the cap I can see the coolant rushing. The overflow is clear. In the middle on top is a inverted cup intregal with the radiator with a vent line running across and down the side. Does that vent back into itself? Tom Btw, The fan belt is new and adjusted with 1/2 inch deflection. Too bad there isn't a shroud for these radiators. Edited May 21, 2009 by P-12 Tommy Quote
greg g Posted May 21, 2009 Report Posted May 21, 2009 the vent tube goes to a rubber tube than to air near the bottom of the radiator. Also folks have a tendancy to over fill these systems. There should be 2 to 3 inches of air at the top of the expansion tank. The room being for expansion. We had a guy who drove a 39 Chrysler who would cuss and sputter everytime he drove the car because he would wait till it cooled down, then fill the coolant up to the brim again, said it boiled over everytime he drove it. I told him to let it burp, then leave it alone. Saw him a couple months later and he said it wasn't running hot and he hadn;t added anything since our discussion. Quote
P-12 Tommy Posted May 21, 2009 Author Report Posted May 21, 2009 (edited) Greg, The right side of the radiator ,of course is where the cap goes. Then there's the one on top in the middle with a vent tube. Two vents? Tom BTW, Thanks for the coolant info. My coolant level is about an inch from the top. Looks like I'm draining some. Edited May 21, 2009 by P-12 Tommy Quote
cwcars88 Posted May 21, 2009 Report Posted May 21, 2009 Tom You said when you open the cap you see the coolant rushing. To me that means the water pump is working and water is flowing. It does not tell me the overflow is not plugged. Just a thought. Quote
P-12 Tommy Posted May 21, 2009 Author Report Posted May 21, 2009 When I would loosen the cap a little, some antifreeze will come out the overflow when it is running hot. Tom Quote
greg g Posted May 21, 2009 Report Posted May 21, 2009 some have the tube integral with the filler some as you mentioned have the little center mounted deal, either way the overflow is seperated from the sealing gasket of the cap so even if you put a pressure cap on it it won't have any effect. But if you havent blown out the tube I would do so even if you just try blowing through it with you mouth to see if its free. Quote
billwillard Posted May 21, 2009 Report Posted May 21, 2009 I havent heard you say your car overheated yet. Don't add any water and drive it 10 miles. If it does not overheat there is probably nothing wrong with it. Quote
BobT-47P15 Posted May 21, 2009 Report Posted May 21, 2009 One thing about these old Plymouths is-- the water in the radiator seeks its own desired level. Which is usually at least an inch below looking full. If I fill mine up to the bottom of the filler neck, it will expel the extra water down to where it wants to be. And it will be fine from there.....won't overheat. Quote
Don Coatney Posted May 21, 2009 Report Posted May 21, 2009 Hey Don, I've got to wait till I get home tonight to take a picture. BTW, the top of the radiator has a round cup in the center with a vent line that runs across and down the side. It's the original radiator. How do you know there is pressure in your cooling system? Explain the pressure symptoms? Quote
P-12 Tommy Posted May 21, 2009 Author Report Posted May 21, 2009 When it was running hot(200 or a little more on the guage) I would stop and pop the hood and untwist the radiator cap one notch and buildup pressure and antifreeze would come out the overflow. That's why I'm wondering what's up. Tom Quote
Don Coatney Posted May 21, 2009 Report Posted May 21, 2009 When it was running hot(200 or a little more on the guage) I would stop and pop the hood and untwist the radiator cap one notch and buildup pressure and antifreeze would come out the overflow. That's why I'm wondering what's up. Tom Sounds normal to me assuming you filled your radiator to the top. Quote
P-12 Tommy Posted May 22, 2009 Author Report Posted May 22, 2009 :)Thanks Don! When I get the chance I'll drain some antifreeze and take it for a run. Tom Quote
Don Coatney Posted May 22, 2009 Report Posted May 22, 2009 :)Thanks Don! When I get the chance I'll drain some antifreeze and take it for a run. Tom No! Take it for a run 30-40 miles and then stop and dont open the hood. The radiator will puke out any excess and seek its own level. Quote
P-12 Tommy Posted May 22, 2009 Author Report Posted May 22, 2009 Ok, I'll try that then. Thanks, Tom Quote
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