12-26-2006, 11:45 PM
Currently having an overheating problem on my '94 968 (155K miles). I really think the waterpump went out, and since I don't have a flywheel lock, and since replacing the waterpump means taking out the timing belts, I took it into the dealer for repair. They are not sure its actually the waterpump, as they have determined that my radiator needs replacing. I have known it has a small leak for some time, though I thought it was just the lower hose. They said there is actually a crack in the lower corner. So, first question - would you replace with a stock radiator ($420), or go with one from Heritage http://www.heritagemotorcar.com/research/rad.htm (price and availability unknown right now)?
Reasons I think this is a waterpump and not just a leak:
Car was using water and would sometimes run a little hot, though never over the top white mark. I just kept topping off it off figuring I would get to the hose soon. However, while driving home after about 40 miuntes, the car started to move above the top white mark, so my first thing to do was to crank the heater up, but at about that point I noticed that the air coming from the vents was cold instead of hot. I pulled the car over and noticed the level was lower then usual. After that I limped the car home by stopping every couple of miles and adding about a 1/2 gallon of water each time. At no time did I get hot air in the cab, no matter engine temp nor whether I had just topped off the fluid. I also noticed that if the system is pressurized, it won't pull the water out of the "overflow" resiviour. I did figure out that if I cracked the little bolt on top of the upper water hose fitting, it would vent steam and de-presurize the system. I could then open the radiator cap on the overflow tank and then water would drain into the radiator, I would add a 1/2 gallon to get everything full again and drive another couple of miles with my eyes glued to the temp guage. When I removed the water hose screw, I noticed that there was no water there, I suspect pressure was building and water was being pushed out of my radiator leak and/or overflow hoses.
If this was just a leak, it wouln't have been that sudden, and if the system was full, I should have hot air in the cab.
I guess this could be the thermostat, but the thermostat is opening when I release pressure and re-fill the system since water will come out of the screw hole if I fill the overflow resiviour all the way up with the screw out. At least I think the thermostat would have to be open ??
Any comments and advice welcome <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />
Reasons I think this is a waterpump and not just a leak:
Car was using water and would sometimes run a little hot, though never over the top white mark. I just kept topping off it off figuring I would get to the hose soon. However, while driving home after about 40 miuntes, the car started to move above the top white mark, so my first thing to do was to crank the heater up, but at about that point I noticed that the air coming from the vents was cold instead of hot. I pulled the car over and noticed the level was lower then usual. After that I limped the car home by stopping every couple of miles and adding about a 1/2 gallon of water each time. At no time did I get hot air in the cab, no matter engine temp nor whether I had just topped off the fluid. I also noticed that if the system is pressurized, it won't pull the water out of the "overflow" resiviour. I did figure out that if I cracked the little bolt on top of the upper water hose fitting, it would vent steam and de-presurize the system. I could then open the radiator cap on the overflow tank and then water would drain into the radiator, I would add a 1/2 gallon to get everything full again and drive another couple of miles with my eyes glued to the temp guage. When I removed the water hose screw, I noticed that there was no water there, I suspect pressure was building and water was being pushed out of my radiator leak and/or overflow hoses.
If this was just a leak, it wouln't have been that sudden, and if the system was full, I should have hot air in the cab.
I guess this could be the thermostat, but the thermostat is opening when I release pressure and re-fill the system since water will come out of the screw hole if I fill the overflow resiviour all the way up with the screw out. At least I think the thermostat would have to be open ??
Any comments and advice welcome <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />
