Water Pump and Running Temperature
Discussion
My 1983 Tasmin 2.8i was recently treated to a new water pump. The engine has a Revotec electric fan. Since changing the pump the running temperature has gone up. Fan cuts in fine. Coolant level fine. Has anyone had such an experience? Do I need a different impeller, or smaller pulley on the pump?? Any suggestions welcome.
The Wedges are quite notorious for having airlocks especially after having new waterpumps, thermostats fitted etc. There's a number of things you can do to rule out some issues. Before making these checks make sure you think about your safety. Keep loose clothing away from moving parts and never touch any part of the engine heated up without using a wet cloth.
1. Check top and bottom rad hoses. The top hose should be hotter than the bottom hose once the thermostat opens. The bottom hose should have cooler water flowing out from the bottom of the rad. If not the thermostat may be stuck in the closed position. Squeezing the hoses will also indicate if there's water flowing through if so the thermostat is open. If not the termostat will need testing to see if it's working. Remove it when its cold and then dip it into very hot water near to boiling - if it's ok you will see it open. If not it will need changing. (potential problem solved)
2. Check to ensure the revotec fan is pulling air through rad if its mounted behind the radiator facing the front of the car. If not swap the wires over to reverse the fan direction. (potential problem solved)
3. An airlock would be indicated by the temp gauge fluctuating between hot and cold instead of remaining at a constant temp. To alleviate this fill the car when it's cold at the swan neck ensuring the expansion tank is filled at least to half full. Run the engine until water spills out the swan neck and then replace the cap which should be a blanking cap. Leave the cap off the expansion tank which should have a pressure spring and run the engine to temp allowing the system to expel air out through the expansion tank. Every so often raise the revs from idle to about 2500 for a few seconds allowing the revs to drop back to idle. Your new pump should push the water round the system at a faster rate when revved harder. If there's air trapped, the water will bubble and burp out the air until the water settles inside the tank. Your cooling fan should cut in at the point where it has been set cooling the water temp down, when it does wait until the fan stops, switch off the engine and allow to cool, top up the expansion tank if and when the level drops before capping off. You should find the system is bled of air and all should be well with the running temp. If you haven't already done, so I'd also fit a fan override switch I to ensure you can switch the fan on especially in traffic. It can take a while to get the air out but usually happens first time round after about 10-20 mins. (potential problem solved)
Hope that helps - somone running a 280 might have some more clues but from my knowledge the same rules apply to the V8s too.
1. Check top and bottom rad hoses. The top hose should be hotter than the bottom hose once the thermostat opens. The bottom hose should have cooler water flowing out from the bottom of the rad. If not the thermostat may be stuck in the closed position. Squeezing the hoses will also indicate if there's water flowing through if so the thermostat is open. If not the termostat will need testing to see if it's working. Remove it when its cold and then dip it into very hot water near to boiling - if it's ok you will see it open. If not it will need changing. (potential problem solved)
2. Check to ensure the revotec fan is pulling air through rad if its mounted behind the radiator facing the front of the car. If not swap the wires over to reverse the fan direction. (potential problem solved)
3. An airlock would be indicated by the temp gauge fluctuating between hot and cold instead of remaining at a constant temp. To alleviate this fill the car when it's cold at the swan neck ensuring the expansion tank is filled at least to half full. Run the engine until water spills out the swan neck and then replace the cap which should be a blanking cap. Leave the cap off the expansion tank which should have a pressure spring and run the engine to temp allowing the system to expel air out through the expansion tank. Every so often raise the revs from idle to about 2500 for a few seconds allowing the revs to drop back to idle. Your new pump should push the water round the system at a faster rate when revved harder. If there's air trapped, the water will bubble and burp out the air until the water settles inside the tank. Your cooling fan should cut in at the point where it has been set cooling the water temp down, when it does wait until the fan stops, switch off the engine and allow to cool, top up the expansion tank if and when the level drops before capping off. You should find the system is bled of air and all should be well with the running temp. If you haven't already done, so I'd also fit a fan override switch I to ensure you can switch the fan on especially in traffic. It can take a while to get the air out but usually happens first time round after about 10-20 mins. (potential problem solved)
Hope that helps - somone running a 280 might have some more clues but from my knowledge the same rules apply to the V8s too.
as the revotec fan was fitted long b4 the water-pump replacement (thats how i understand your opening post), the fan cannot be the responsible.
the normal running temperature during driving has nothing to do with an elecric fan, as the e-fan only comes into force during slow driving in town or during a traffic-jam.
havent you compared the pulley of the old-pump vs new-pump? this said, i even dont know if ford ever fitted different sizes of pulleys.
most pumps will come without pulley anyway...so you are "forced" to use your old pulley.
the normal running temperature during driving has nothing to do with an elecric fan, as the e-fan only comes into force during slow driving in town or during a traffic-jam.
havent you compared the pulley of the old-pump vs new-pump? this said, i even dont know if ford ever fitted different sizes of pulleys.
most pumps will come without pulley anyway...so you are "forced" to use your old pulley.
just a annecdote from my first V6 Tasmin:
when the car came to me the viscous-fan was seized. i was able to free it, but the viscous coupling was weak and the bearing worn. i used the car for several weeks in summer and the cooling temperatues were spot-on.
instead of buying a new viscous coupling, later in winter, i decided to convert it to an electric fan.
i used a fan from a modern BMW which was collecting dust in my garage.
after i installed the fan the normal running temperatue of the engine increased by around 10-15degrees.....and on a hot-summerday it was often on the limit, even during driving. the radiator was not blocked, as pre-caution i installed a new one...prolem remained the same.
by the way: the fan was mounted behind the rad and was sucking the air through the rad. also the fan was built for this "sucking"-application. so everything fine.
my other Tasmins, which followed, were never converted to e-fan and they never showed any problems with the running-temperatures.
when the car came to me the viscous-fan was seized. i was able to free it, but the viscous coupling was weak and the bearing worn. i used the car for several weeks in summer and the cooling temperatues were spot-on.
instead of buying a new viscous coupling, later in winter, i decided to convert it to an electric fan.
i used a fan from a modern BMW which was collecting dust in my garage.
after i installed the fan the normal running temperatue of the engine increased by around 10-15degrees.....and on a hot-summerday it was often on the limit, even during driving. the radiator was not blocked, as pre-caution i installed a new one...prolem remained the same.
by the way: the fan was mounted behind the rad and was sucking the air through the rad. also the fan was built for this "sucking"-application. so everything fine.
my other Tasmins, which followed, were never converted to e-fan and they never showed any problems with the running-temperatures.
Sorry for taking so long to add further observations. I've changed the temperature sensor - no change in recorded temperature. The electric fan was new. Sorry I didn't make that clear. Fan cuts in and out as it should.
However, when I check the engine temperature with my point and shoot infra red thermometer, I can find no place where the temperature is above 91C max. I think the problem is the inaccurate temperature gauge, since when it says 90C the temperature with my infra red is nowhere near that! The gauge seems to be overreading.
However, when I check the engine temperature with my point and shoot infra red thermometer, I can find no place where the temperature is above 91C max. I think the problem is the inaccurate temperature gauge, since when it says 90C the temperature with my infra red is nowhere near that! The gauge seems to be overreading.
I have a 1985 280I and it always showed the temperature gauge as being hot. Of course when driving you see this it worries you.
I called TVR in Canada and I was told that they have had many calls about this problem. I was told that they used insufficient ground wire on the gauge and to add a new ground wire to the battery and the problem should be solve. I have not done that yet but wanted to pass it on .
Mark
I called TVR in Canada and I was told that they have had many calls about this problem. I was told that they used insufficient ground wire on the gauge and to add a new ground wire to the battery and the problem should be solve. I have not done that yet but wanted to pass it on .
Mark
derekbalaam said:
Sorry for taking so long to add further observations. I've changed the temperature sensor - no change in recorded temperature. The electric fan was new. Sorry I didn't make that clear. Fan cuts in and out as it should.
However, when I check the engine temperature with my point and shoot infra red thermometer, I can find no place where the temperature is above 91C max. I think the problem is the inaccurate temperature gauge, since when it says 90C the temperature with my infra red is nowhere near that! The gauge seems to be overreading.
infrared themometres are never showing the "truth"....they are good for finding faults (like 1 cylinder not runnign well, thereofre one ex-manifold less hot then the other) .However, when I check the engine temperature with my point and shoot infra red thermometer, I can find no place where the temperature is above 91C max. I think the problem is the inaccurate temperature gauge, since when it says 90C the temperature with my infra red is nowhere near that! The gauge seems to be overreading.
this said, IR´s are always underreading
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