Morris Minor Owners Club

hi everyone a quick question,myrtle is getting very hot at tick over.i have allways had clean coolant in the car,the stat is opening up.i took the rad out and backflushed it.i got a bit of muck out but nothing to worry about.i then put some descaler in there and let it do its thing . i got a little bit more muck out.one thing i have noticed is when the rad cap is takrn off when warm,there does not seemto be any pressure there.the rubber on the cap looks a bit tired,could this be the reason for getting hot.its fine when there is air being forced through when the car is in motion.and yes the fanbelt is tight,many thanks dale.

It could well be the cap, and for the cost, it would be well worth trying another one first.

If the rad cap is shot, the water will boil quicker, as water under pressure takes longer to boil. Make sure new cap is 4Lbs pressure or the bypass hose will tend to burst. Don't rule out silted up water ways in the block though.

But the water should not be near 'boiling' point anyway - it should sit pretty much at the thermostat setting because the radiator is plenty big as standard. Is you are loosing water - then yes worry about the cap - but how are you judging the 'hot at tickover' ? Is it just the gauge going up slightly - or is moving off the scale ?

more importantly, is the gauge accurate???

the gauge is only 3 years old,so it should be ok the temp is going up to 90 not far off boiling point,i am not getting any smells comming from a hot engine,i have got a new cap,so ill find out on saturday.i am not loseing any water.

normal engine temperature is around 70-80 so 90 is not that hot, a pressured water system will run to about 110 before it boils

As Rob says, 90C is fine, especially if you have an 88C thermostat fitted. I wouldn't start to worry until it reaches 100. Antifreeze and pressure will let it go a bit higher than 100 before it boils.

But if worried - fit a 74 degree stat for summer, and keep the higher rating one (if it IS higher) for winter!

ok thanks everyone i was just a bit alarmed at the rate at wich the temp went up,it soon went down when i got moving another problem solved.