WE are going mad...please help....
My stepson has a ZR......last week he had the head gasket changed because the car overheated and would not start....what we though was due to a possible radiator leak.
To cut a long long story short the heater didnt work before this HGF and neither does it work now.
We have bled the system many many times a day for a week now. Still no heater.
He took the car out the other night and suddenly he noticed the temp very high.
He stopped , checked under the bonnet, and set off again and the engine ran normally !!!!! but still no heater.
We think the water pump may be at fault and performing so weakly or failing intermittently, it is not able to shove the water around the heater matrix.....only possibly shoving enough water around the system to keep the engine runnable with the temp gauge almost half way. We have taken the pipes off and started the engine and watched to see how efficient the pump actually pumps water......hardly anything.
there are no screeching or grinding or vibrating noises form the pump.....we think the impeller may not be driving as it should to shove water round the system.
The original failure of the HG may now have been due to this water pump not performing and NOT a leaking radiator.
Are we right in what we are thinking or are we way off track?
How can we check the performance of the water pump?
We have backflushed every water pipe and the heater matrix so we are confident there is no blockage.
There has been a new thermostat fitted, HG, head skimmed, timing belt and head bolts.
Can the water pump be driven by the timing belt but not pump any water round?
I know this doesnt seem right as the engine is not overheating ( has done twice I know....once with main failure and 2nd time the other night) but generally the temp. gauge is just below half way.
Is it possible for the pump to work barely enough to keep the engine running but not drive water through the heater matrix?
Please please give us any clues you have.
Thanks in advance.
My stepson has a ZR......last week he had the head gasket changed because the car overheated and would not start....what we though was due to a possible radiator leak.
To cut a long long story short the heater didnt work before this HGF and neither does it work now.
We have bled the system many many times a day for a week now. Still no heater.
He took the car out the other night and suddenly he noticed the temp very high.
He stopped , checked under the bonnet, and set off again and the engine ran normally !!!!! but still no heater.
We think the water pump may be at fault and performing so weakly or failing intermittently, it is not able to shove the water around the heater matrix.....only possibly shoving enough water around the system to keep the engine runnable with the temp gauge almost half way. We have taken the pipes off and started the engine and watched to see how efficient the pump actually pumps water......hardly anything.
there are no screeching or grinding or vibrating noises form the pump.....we think the impeller may not be driving as it should to shove water round the system.
The original failure of the HG may now have been due to this water pump not performing and NOT a leaking radiator.
Are we right in what we are thinking or are we way off track?
How can we check the performance of the water pump?
We have backflushed every water pipe and the heater matrix so we are confident there is no blockage.
There has been a new thermostat fitted, HG, head skimmed, timing belt and head bolts.
Can the water pump be driven by the timing belt but not pump any water round?
I know this doesnt seem right as the engine is not overheating ( has done twice I know....once with main failure and 2nd time the other night) but generally the temp. gauge is just below half way.
Is it possible for the pump to work barely enough to keep the engine running but not drive water through the heater matrix?
Please please give us any clues you have.
Thanks in advance.