overheating TF

David Aiketgate wrote: I would try flushing the cooling system through,especially the rad and underfloor pipes.:shrug:

It's a brand new rad too, I checked the new & old when replacing it & they were both OK, I'll give the underfloor pipes a go, any hints on the best way to do it?

Steve wrote: They should vary slightly in temperature and should be reasonably firm but still squeezable if that makes sense

From memory, they were quite soft when up to temp when the heater was set to hot, but quite firm when set to cold. I'm away till tomorrow so can't check till I get home.

The oft used method is a crushed up dishwasher tablet in the expansion tank and run the car up to temp, or take it for a run. When it's cooled down,undo all the bleed vales, then disconnect one of the hoses to the under floor pipes and jam a hosepipe up it.Give it a good 'colonic' clear out. :whistle:

What if I were to disconnect the pipes at each end, engine & rad, the run the hose through each? Would that work?

Worked for me when we had hgf done.

Got loads of gunk out of it.

I'm afraid I cannot help, but just as a matter of interest so as not to confuse others, or is it me who is confused, the cooling circuit diagram posted by mgbluestreak on page two shows the hot water entering the rad via the bottom hose and the cooled water leaving at the top. This I am sure is contrary to what I have believed for years (55 ish). Am I really going senile or am I missing something ???

COMMANDER wrote: I'm afraid I cannot help, but just as a matter of interest so as not to confuse others, or is it me who is confused, the cooling circuit diagram posted by mgbluestreak on page two shows the hot water entering the rad via the bottom hose and the cooled water leaving at the top. This I am sure is contrary to what I have believed for years (55 ish). Am I really going senile or am I missing something ???

That's the way they are on the early cars for some reason.



I managed to get home for a couple of hours today, so had another play. flushed all the pipes & everything seems to flow properly.

Strangely though I noticed that when the heater is set to cold & the rad fan comes the return pipe from the rad cools down quite quickly, but when the heater is on hot it warms up as you'd expect. So it looks as if the rad fan is Cooling as it should but the water isn't flowing through the system.

Really confused now :bang:

yes did catch that but wonderd what it was about.....check out these 2 charts

.........the first is with prt.........ive seen a thread where it is common practice to reverse flows in race engines to give a different balance of coolant flow ..........making any scense or have i just confused everyone with these flow charts

Daz wrote:
That's the way they are on the early cars for some reason.



I managed to get home for a couple of hours today, so had another play. flushed all the pipes & everything seems to flow properly.

Strangely though I noticed that when the heater is set to cold & the rad fan comes the return pipe from the rad cools down quite quickly, but when the heater is on hot it warms up as you'd expect. So it looks as if the rad fan is Cooling as it should but the water isn't flowing through the system.

Really confused now :bang:

looking at the diagrams again, it looks as if the rad & fan are doing their job, but for some reason the stat is closing stopping the coolant from flowing back through the system, which would explain why the car never overheats when the stat is removed, but it's had 4 new stats, so it can't be that, can it?

I did notice that if I blip the throttle the coolant seems to blow back into the bottom of the expansion tank, only for a split second, I'm not sure if this is normal or not.

Does anyone have a pic with the stat fitted in the housing? It's got me doubting whether it's fitted the right way round, I'm 99% sure it's fitted correctly.

found some pics tell me if there not the ones your looking for

That looks like how mine is fitted, if there's another outlet under his thumb


next step will be fit a PRT at the front of the car, does this diagram look correct for the conversion, sorry mgtfbluestreak I borrowed your pic, moved from the back of the car to the front, outlined in red.

Just realised I should have done the mod on the earlier diagram, not the later model diagram, but essentially cut the flow pipe into the rad, slot the PRT in & then feed the part that would normally go to the heater bypass across to the return pipe of the rad.

Bit like this

more thermostat housing images