hi everyone,
can i ask for advice on the issue i have with my 1999 mark 2 mgf mpi with running too hot sometimes.
just bought it privately, 60,000 miles, 1.8 mpi, last owner had it ten years, its been well looked after, head was done 4 years ago, new rad, stainless steel water pipes etc.
anyway when i went to view it, drove it , checked everything, all good, drove it home the following week on the hottest day of the year in rush hour about 50 miles all good ran perfectly, drove it around the town that night same perfect, 2 days later took it for drive temperature gauge went right up and started to blow steam from expansion, stopped and waited for it to cool, topped it up with about 1 litre of water and drove it home.
investigation - car idles fine, doesnt over heat if idling, after it did overheat initially i noticed radiator fan didnt come over so did the usual test disconnecting the temp sensor to test fan and it came on so fan is good, then i changed the thermostat and put in one with jiggle valve and then new inlet manifold gasket along with cleaning the inlet manifold jiggle valve. topped up with 50% oat coolant and ran the car over a few weeks just short trips but still noticed sometimes the temp starts to go up until i turn the heater fan on full then it cools down, fan at front on radiator kicks in aswell. oil is clean, not loosing any coolant, no smoke.
i have noticed i have no return flow to header tank what so ever, reading the forums there are 2 jiggle valves, one on the inlet manifold i cleaned and one of the passenger side on the engine which i havent looked at yet which i am aiming to look at tonight.
i am confused as i understood the jiggle valves are there to let any air out of the system/head, i dont think they are there to return a small flow of coolant to the header tank but looking at the cooling system diagrams they all show hot coolant returning to the header tank and other users on the forums also say there should be a return flow which i do not have.
anyone have any clues? could it be the waterpump?
thanks
martin
can i ask for advice on the issue i have with my 1999 mark 2 mgf mpi with running too hot sometimes.
just bought it privately, 60,000 miles, 1.8 mpi, last owner had it ten years, its been well looked after, head was done 4 years ago, new rad, stainless steel water pipes etc.
anyway when i went to view it, drove it , checked everything, all good, drove it home the following week on the hottest day of the year in rush hour about 50 miles all good ran perfectly, drove it around the town that night same perfect, 2 days later took it for drive temperature gauge went right up and started to blow steam from expansion, stopped and waited for it to cool, topped it up with about 1 litre of water and drove it home.
investigation - car idles fine, doesnt over heat if idling, after it did overheat initially i noticed radiator fan didnt come over so did the usual test disconnecting the temp sensor to test fan and it came on so fan is good, then i changed the thermostat and put in one with jiggle valve and then new inlet manifold gasket along with cleaning the inlet manifold jiggle valve. topped up with 50% oat coolant and ran the car over a few weeks just short trips but still noticed sometimes the temp starts to go up until i turn the heater fan on full then it cools down, fan at front on radiator kicks in aswell. oil is clean, not loosing any coolant, no smoke.
i have noticed i have no return flow to header tank what so ever, reading the forums there are 2 jiggle valves, one on the inlet manifold i cleaned and one of the passenger side on the engine which i havent looked at yet which i am aiming to look at tonight.
i am confused as i understood the jiggle valves are there to let any air out of the system/head, i dont think they are there to return a small flow of coolant to the header tank but looking at the cooling system diagrams they all show hot coolant returning to the header tank and other users on the forums also say there should be a return flow which i do not have.
anyone have any clues? could it be the waterpump?
thanks
martin