another over heat one


right i bought my sporty around 6 weeks ago and the other day the water pump seized so i fitted a new one along with a cambelt the water that came out of the cooling systym was very rusty ive put it all back together and only around 2/3 of the rad gets hot and the car runs really quite hot would this be the rad knackered through rust or an air lock


First job.
Change the thermostat. Get the correct type approx £20. Use a new gasket + sealant and take care you do not overtighten the nuts ... 5 ft lbs max. Fit the thermostat so that its toggle is uppermost - wrong way and you get an airlock.

Whilst coolant is drained, thoroughly flush the radiator and then flush the engine block. Fill only with water and run the engine. If radiator proves OK then drain and refill using antifreeze mixture.

If it continues to overheat

If it continues to overheat once you have done all of this (like i did), then you can get yourself a Kenlowe electric fan which WILL keep you coolent at a set temperature set by yourself.

they retail from kenlowe at around £140 it does make life alot easier as you can do away with the viscous fan which will also increase ur engine power slightly and i also noticed a slightly better economy (about an extra 30 mile to a tank)

hope this helps


More ........

If the radiator is blocked then get the radiator recored .. cost is approx £100. Result is a 'new' radiator - top/btm reserviors are renovated and the whole central core is replaced. If its internal rust then you waste your time cleaning - it will rupture/leak. Time wasted.

Putting a 'cooling fan' is not advised. If the radiator is blocked, the coolant flow is drastically reduced and the coolant in the engine block will be substantially hotter than coolant in the radiator. This creates 'hot spots' usually near the exhaust outlets. Result will be a blow head or blown headgasket. Expensive !
I suggest you first change the thermostat. Thermostats usually fail and stick partially open - hence lack of coolant flow and very hot coolant and possible cool sections apparent in the radiator. If a new thermostat fails to solve the flow issue then remove the radiator and take it to a repairers such as MotorRads. They will test it and advise.

quick follow up i have

quick follow up i have ordered a new thermostat and will fit it later but the old one opened right up in boiling water,the other thing i noticed was the viscous fan was not working so i took if off and heated the coil on the front sure enough the pin turns ok but the fan doesnt seem to lock up can this be repaired or do i need to replace


Remove the radiator cap. Rev the engine. Does the water rise into the filler neck?

1. Did you fit the replacement water pump having checked it worked?
2. Is the water pump belt tight?
3. Did you fit the replacement thermostat with its toggle [hole] uppermost?
4. Check the condition of the radiators seal within the cap. Is the read pressurising when hot?
5. Which part of the radiator remains cold?

FWIW it's sounding like

FWIW it's sounding like another a duff water pump.

Dave with a Sporty

Dave with a Sporty

the rad is cold above the

the rad is cold above the bottom hose about 6 inches across
yes thermostat was fitted ok and the pump is new, i took the rad of and flushed it both ways and there were chunks of rust comming out

fan wasnt cutting in so ive

fan wasnt cutting in so ive turned the coil on the front now its on all time and the gauge is reading bang on half way and doesnt move i guess this is compensating the faulty rad atleast i can use it untill a new rad is sorted

Test not done .......

Is the temperature gauge indicating above half way? Half way is about correct.

You have yet to look inside the radiator cap. Coolant COLD. This will show if the water pump is working. The report indicates the coolant is not circulating but the thermostat is apparently opening.
First ensure the replacment water pump is not a dud!

Remove the radiator cap. Look down at the coolant whilst the engine 'ticks over' Significantly rev the engine. Does the water rise/lift into the filler neck? The water pump should pressure the coolant upwards.

A distinct 'rise/lift' in coolant level must be seen. Usually its very obvious since the coolant will be disturbed as it rises/lifts under the load of the water pump. If the coolant remains flat and undisturbed then the water pump is not working.

If you decide the water pump is OK then the next task is removal of the radiator. Take the radiator to a radiator repairer and get it tested - flow and pressure. The previous owner might have failed to maintain the coolant's qualities. Take their advice if they suggest a recore. Using Halford's radflush might be a waste of cash especially when rust lumps have been seen in any cleanout. The radiator will be corroded to excess. Get it recored. Could be cheaper than a late night radiator rupture on a motorway!