TEMP TOO COOL ON THE FREEWAY

pcorro · Post by **pcorro** » Tue Jul 12, 2011 1:29 am

gday,new to this forum, hope someone can help me. i have a 5ltr holden v8 in the land cruiser,my problem is on my last trip on the highway the temp reading went down to the cold mark and the heater didnt blow out hot air any more,but when i stop or slow down at the towns it slowly comes back to about the quarter mark.its fine driving around the suburbs.THANKS IN ADVANCE

ian.stewart · Post by **ian.stewart** » Tue Jul 12, 2011 4:14 am

Radiator thermostat sounds like it is stuck open, keeping the rad in circulation all the time, with it stuck open the engine will not normally get fully hot, or take ages to do so,

DEVONMAN · Post by **DEVONMAN** » Tue Jul 12, 2011 8:36 am

ian.stewart wrote:Radiator thermostat sounds like it is stuck open, keeping the rad in circulation all the time, with it stuck open the engine will not normally get fully hot, or take ages to do so,

But just once.

Cheers Denis

marcjagman · Post by **marcjagman** » Tue Jul 12, 2011 10:13 am

May be the radiator that's too big. Does it have elec fans with a thermo switch?

DEVONMAN · Post by **DEVONMAN** » Tue Jul 12, 2011 1:00 pm

marcjagman wrote:May be the radiator that's too big. Does it have elec fans with a thermo switch?

Pcorro said it happened on the last trip on the highway and I would therefore assume the engine ran fine before. Even with a rad that is too large the thermostat if working properly would not allow coolant through the rad until the engine is up to the designed working temperature.

Cheers Denis

pcorro · Post by **pcorro** » Wed Jul 13, 2011 1:29 am

it does have a new radiator and twin 10 inch thermo fans with thermostat if thats any help.

unstable load · Post by **unstable load** » Wed Jul 13, 2011 6:15 am

Try another thermostat. It's going to be easiest and cheapest to do.

DEVONMAN · Post by **DEVONMAN** » Wed Jul 13, 2011 8:18 am

unstable load wrote:Try another thermostat. It's going to be easiest and cheapest to do.

I agree. try a new thermostat.
Think of all the fuel you will save.

You can do a check on your existing thermostat as follows,

Start the engine from cold. If the thermostat is stuck open then the top hose will gradually heat up, but if the thermostat is working properly the top hose will stay cold for about 4-5 minutes and then suddenly get very hot.

Cheers Denis

pcorro · Post by **pcorro** » Wed Jul 13, 2011 11:34 pm

thaks for your help,i will attemt to put one in on the weekend and let you know how it went. thanks again

pcorro · Post by **pcorro** » Sat Jul 23, 2011 6:20 am

it was the thermostat,i even did it myself,not bad for a butcher(trade), thanks for the advice