hello chaps i need your help plz i got a townace which keeps over heating if i run around localy 30 miles radius its fine ? but if i do a run of 55miles on the moterway she overheats ? and i need to put in around 4-5 litres of water strange just 12 mounths ago had a new radiator and rad cap 13lbs so i dont think its that ive checked the oil dipstick no signs off green muck or when i take off the oil filler cap same no green mess when it over heats seems to push up into the expansion tank steam etc plz help what is the problem thanks in advance for the anticipated help you all may other i check in daily thankyou all again regards nigel r

- (#528) nigel risk, 4 Apr 05 20:11

Suggestions? Read the archives. You've got a tiny leak that is letting water out and air in, when under sustained high pressure. Carry out hot and cold pressure tests, possibly a test of the viscous coupling (to be safe), and a bit of prayer...

I presume the new rad cap is the official Toyota float-style item?

- (#528) David Miller, 5 Apr 05 01:59

When you say she overheats, how do you know? Is the temperature gauge going up?

You need to know whether the coolant is being pushed out because it overheats, or whether it overheats for some other reason and that causes the coolant to be pushed out.

To reduce the risk of damage while you investigate:
1. Check your coolant level in the engine really often, daily? and make sure it is within 25mm of the underside of the metal filler cap.
2. Fit an Ace Answers temperature gauge modification,
- then you'll have a better idea what's going on.

- (#528) Dave Mason (Sussex), 5 Apr 05 09:09

Hi thanks for reading, my problem is that my temperature gauge goes high pretty quickly and water is being lost through the expansion tank, local garage done a check on the head gasket (this was fine), changed the radiator cap fan, kicks in on start-up when engine cold, unsure if it does when hot, any pointers would be most welcome, thanks again

- (#528) Andy Barnett, 22 Apr 05 13:51

The fan will always be turning but, when the engine is cold, the fan will "freewheel" to a certian extent and turn at much less than engine speed. As the radiator heats up, and warm air is drawn thorough the fan, a thermo device, in the fan, "stiffens" the fan drive so that it turns much faster. You can check the operation of the fan, with a hot engine, and at speed, by driving with the passenger seat up and observing it's operation. If the fan tends to slow down, or stop, under these conditions, you need to check the fan viscous coupling. There is a lot of information about this in Ace Answers

- (#528) John Davis (Leics), 23 Apr 05 02:57

Sounds like it could be a blocked radiator or jamed thermostat.
When it gets hot, check the temp of the rad hose under the expansion tank. If its cold, suspect a blockage of some kind
- (#528) dave Bright (Bournemouth), 23 Apr 05 03:14