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jaguar S Type 4.0L V8 engine overheat no heat in car
I have a 2001 S Type jag that developed an intermittent overheat problem about 12 months ago and I should say that at the time it was a very rare occurance what used to happen was the temp guage rose quickly into the red and a HIGH ENGINE TEMP warning showed in the dash I put the heater to high and the temp immediately dropped back to normal and stayed that way for weeks on end no matter what kind of mileage I did for instance I have done 100 motorway miles at 70 mph and not had a problem and driven in town traffic for weeks and not had a problem and then it will start again on a town drive after searching the internet I was told a faulty temp sensor in the top radiator hose can cause fake overheat symptoms so I replaced it and all was good until it has started again, I was told by my local garage that the water pumps on these cars can be problematic because there is a plastic impeller that can sometimes come lose I have just replaced the pump 2 days ago so far the car hasn't overheated but now there is no heat in the car. Before fitting the new pump and attempting to bleed the system of air there was no flow showing back to the expansion bottle which there is now, there has never been any loss of coolant, I believe the heater control valve is working because the pipes running into the car are getting hot both flow and return and I had this valve replaced a few years ago, I also had the thermostat replaced when this all started 12 months ago I am now getting worried that there is a blown head gasket but there is no water in the oil or oil in the water but there is cream on the oil filler cap but I believe this is not 100% proof and the engine runs perfectly fine and has just passed its emissions test. Any advise much appreciated.
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sorry for the long post but thought its best to give as many facts as possible.
Hey Britman! Are you positive about the temperature of the hoses going into the heater core from the heater control valve? I ask because I know the exhaust runs close to the hoses, and can make the hoses feel hot when they're not.
Have you tried driving the vehicle since doing the pump? It honestly sounds like the heater core is still air locked from having the coolant drained out during the water pump service. Also, do you notice a difference in heat from the passenger to the driver side?
