ive got a wierd qeustion here. i have a 73 mavi- grabber and the top radiator hose gets very tight after running a bit . i dont mean when it warms up , i mean after about 1 1/2 min.s of running ,so i know its not hot . but it is building up alot of pressure. if you open the radiator cap half way it trys to blow it off with vcold water in it . i have a 302 , new radiator , fasn shroud , 6 blade fan , new hoses. it did the same before i put all the new parts on it .and still now no difference.i hoping it is not a busted head , but i dont know what else it might be . ive checked for signs of head problems , but no water in oil or vise versus,and no waterin exhaust. any ideas???
Hmmm, guys, didn't Ford change the water pump direction somewhere along the way? Could yours be going the wrong way for these cars? Seth
Are you getting a slimy film on your windshield interior or a wet floor board? (bad heater core) We assume you changed the Tstat also? Just throwing things out here. :shrug:
I have a hard time imagining the problem being a reverse rotaion water pump. :confused: No matter what pump you have it's not going to turn in reverse unless the engind runs backwards. The impellor may face in the opposite direction but I would think that would only slow down the flow of water if anything. I'm just guessing also but the main two things that come to mind is stuck thermostat or blown head gasket. If it's not the thermostat I think I'd do a compression test.
Does the engine overheat? Is this causing a driveability problem? Do you have the wrong radiator cap on it? If you let it run does it force coolant out the overflow? Have you run it for half hour? Just trying to establish what is going on here. Dan
Ray, you're exactly right. I ran what I thought was a standard-rotation aluminum pump for 2 years with no problems. Popped the motor last year and broke the water pump and as I looked at it, sure enough the impeller was a reverse-rotation. Never ran hot, but a couple times I wondered if I was gonna make it back to the pit without getting hot. No problems. 'Course with running alcohol now, I may have a problem heating it, especially with the correct water pump. I should probably build a primer (start & idle on gas) system for it, but right now, I'm just too lazy:banghead3
Mine does the same thing ... I've had the heads on and off twice. It used to run hot but had the same pressurization symptom as yours. I ended up switching to a 180 thermostat with a hole drilled in it to keep the water moving. It definitely runs cooler now but will still puke water sometimes when it shouldn't. I'm thinking some sort of head leak into the coolant somehow but have no ambition to fix it since it's running fine. If I ever need to fix it I'll probably just swap it with a roller 5.0 ...
Ok , I Did Put A New Thermostat In It Also , And It Is Not Running Hot. It Is Showing About 180 Degrees On A Mechanical Aftermarket Gauge , And That Is While Running It Atleast An Hour One Way Through Heavy Traffic . So No Over Heating. Uh , I Put A New 13 Lb. Radiator Cap At The Same Time I Did All The Rest Of The Stuff. The Only Thing I Have Replaced Is The Water Pump And It Is Supposed To Be The Right One By Part # , And It Does Push Alittle Water Out Of The Over Flow Hose But Only After I Kill It And It Is Setting . But Not Alot. And No Leaks In The Heater Core , I Checked That Also.
I guess the true test ... which I haven't done yet ... is to have a radiator shop test for fuel or exhaust gases in the coolant .. if it's there then you know for sure what the problem is. If you get it figured out let me know becuase I haven't been able too ...
The heater core may not leak but could still be clogged. Try bypassing the heater core and see what happens. Just a guess. -Erick
overheating NAPA sells a block tester from universal test tool co that will tell you if you have combustion gases in your cooling system about $30.00 easy to use
ok i 'll check that out correct me if im wrong , but if the heater core was clog it would be bypassing it self right , what i mean is that shouldnt effect the pressure in the radiator right?
