Thermostat

skiff1, Nov 25, 5:44pm
So how do I test one? Landini ghibli 100, Perkins 1004.4 engine
stevo2, Nov 25, 5:48pm
Do you suspect its jammed open taking ages to warm up, or shut overheating?
skiff1, Nov 25, 5:52pm
Tractor went right into the red and the heat alarm came on while idling. Radiator was stone cold. Have pulled out the thermostat and pushed it open while cold. Soaked it in boiling water and pushed it open. No difference in resistance.
stevo2, Nov 25, 5:56pm
When its closed, drop it into a jug of boiling water, see if it opens or not. Most thermostats jam open rather than closed
intrade, Nov 25, 5:56pm
your not suposed to push it open it is supposed to open up with hot fluid only
panicky, Nov 25, 6:02pm
thermostats should be heated from cold, not shocked by being dropped into boiling water, what application does that ever occur in? The temperature rating is when they start opening. They fully open about 9 degrees above their rating.
franken1, Nov 25, 6:16pm
Correct. Also put a thermometer into the water to ensure the thermostat starts to open at the rated temperature. It may open but if it's doing so at a hotter temperature, it'll cause overheating.
brapbrap8, Nov 25, 6:24pm
Wouldn't it work to replace the thermostat with a straight pipe, and see if it still overheats?
If it then runs cold then that is a good sign the thermostat was not opening.
toyboy3, Nov 25, 6:31pm
Is the pump impeller still fastened to the shaft? And circulating the coolant
sr2, Nov 25, 6:32pm
Oh my God; In hindsight I should have invested heavily in companies that manufacture thermostats some 40 odd years ago!

Never in the history of automotive maintenance has one small innocuous mechanical component been blamed for so many cooling system failures only to be exonerated after the purchasing and installation of a replacement!
rojill, Nov 25, 6:33pm
Yep, just remove the thermostat, refit the housing, run the engine and if it runs cold then the stat is stuffed.
skiff1, Nov 25, 6:37pm
that's the next suspect to look at.
kazbanz, Nov 26, 6:26am
Skiff-purely my opinion here. You have opened the "pipe" up and plucked the stat. You will need to bolt the thing back together anyway so why not toss a new stat in ? -$20 part in a $10000 machine.
skiff1, Nov 26, 3:00pm
yep, but I want to know if it was the problem, or if I need to keep looking. It will get a new one either way.
skiff1, Nov 26, 4:27pm
Update, impellers loose on shaft too
kazbanz, Nov 27, 11:57am
Spinning loose-no drive or just a bit rattly?
THAT sounds like a much more likely culprit.
skiff1, Nov 27, 1:13pm
spinning loose
kazbanz, Sep 6, 7:19pm
Sounds like you have found your problem