I've replaced the water pump (following joys of snapping 2 bolts, drilling out and cleaning threads and snapping tap off then grinding tap out and helicoiling) and the car now warms up at a normal rate but keeps getting hotter until its just in the red. Then the thermostat opens and it cools to normal. Its then fine if working quite hard (up hill or reasonable speed on the flat) but gets hot again on long, slow down hill runs (its automatic so I think the revs are virtually at idle - series 1 car so no rev counter).
So far I've checked tower waterway is clear (good flow back to radiator). back flushed the system. Taken temperature sender out and put the garden hose on to that waterway for 10 minutes. Cleaned the water system with the 'dishwasher cleaner' method. back flushed it again. Fitted a new thermostat. Following a chat with Pikie at the Bristol classic car show (nice to meet him), I re-filled the cooling system with the front of the car on ramps to ensure all the air came out.
I convinced myself that the bypass pipe must be blocked so removed the pump tonight and its clean and clear.
I've also bought a handheld Infra red temperature reader and the stat is opening at the right temperature and the sender is telling the truth (when its hot on the gauge, that part of the inlet manifold really is hot).
before I changed the pump I've never had overheating problems (owned the car 20 years) and the radiator was new a couple of years ago.
The only thing I can think is that the new pump doesn't pump very well. It looks different inside, the new one having straight impellers and the old curved ones. Does anyone have any advice?
Thanks,
James
So far I've checked tower waterway is clear (good flow back to radiator). back flushed the system. Taken temperature sender out and put the garden hose on to that waterway for 10 minutes. Cleaned the water system with the 'dishwasher cleaner' method. back flushed it again. Fitted a new thermostat. Following a chat with Pikie at the Bristol classic car show (nice to meet him), I re-filled the cooling system with the front of the car on ramps to ensure all the air came out.
I convinced myself that the bypass pipe must be blocked so removed the pump tonight and its clean and clear.
I've also bought a handheld Infra red temperature reader and the stat is opening at the right temperature and the sender is telling the truth (when its hot on the gauge, that part of the inlet manifold really is hot).
before I changed the pump I've never had overheating problems (owned the car 20 years) and the radiator was new a couple of years ago.
The only thing I can think is that the new pump doesn't pump very well. It looks different inside, the new one having straight impellers and the old curved ones. Does anyone have any advice?
Thanks,
James