Over Heating Engine

john432

ok, back with exactly the same problem, to make it clear, it only starts to overheat at motorway speed 70mph and within 5 mins, anything under that and the engine temp is fine.
Same as already stated, no oil in radietor and no water on oil, no mayo effect on oil filler cap. Expansion bottle will expand and push out coolant when it starts to get warm. Only got to slow down and the gauge will go to normal.
Thoughts please.

londonTiger

flush and drain the heater matrix and radiator - a lot of crap gets lodged at the bottom of radiators and heater matrix. It's easier to flush the radiator than it is with the matrix - the matric is just harder to work with because of it's location and the fact that you need special tools to effectively do a flush.

Check the water pump (timing belt) service to make sure it's been replaced.

Some cars with plastic impellers have failing water pump issues because the impeller starts freewheeling after getting loose from the rotating shaft.

water pump fail is either a fail or not. It doesn't really become "less efficient" at pumping. based on your overheationg issues at high speeds it sounds like maybe there is some blockage/conestion in your system so the heater matrix and the radiators have become clogged up.

Can your reduce the overheating by driving at slower speeds, say 50mph-60mph?

john432

yes driving at 50 / 60 it is fine, most of my driving is at that speed (country roads), which is why it has taken several weeks for the problem to happen again.
It is going to garage next week, yes the radiator is the first thing that is going to be checked, flushed and drained.
Thanks.

breton_2

john432 wrote: »

Garage have come back and said, nothing wrong. No evidence of head gasket failure. Temperature of engine / coolant are correct. Thermostat and coolong fans working.
So, will run the car as normal, and see if it happens again. Garage advise to change thermostat and coolant if it does it again.
Hopeing it ia just a one off situation. At least by stopping immediately it stopped any damage to engine.
Will post back if any thing happens again. Thanks all.

hope it runs fine, good luck to you.

john432

It has now had a new thermostat, water pump and radiator.
Now running at NORMAL tenperature at motorway speed.
Thanks for all your advice.

Crabman

john432 wrote: »

It has now had a new thermostat, water pump and radiator.
Now running at NORMAL tenperature at motorway speed.
Thanks for all your advice.

That's good news, glad it's been sorted.

Thanks for coming back to update us.