Ridiculous! Thermostat help?

[adventure bob]

Have managed to check the thermostat operation? Is it working right? Id make sure before dropping $200 on a thermostat.

I guess my question is why do you think its not reaching operating temp? Is it a gauge indication or is it truly running cold? Can you stick your hand on the head?
In the list of things to check, the order I would suggest is: run it for an amount of time where it should be up to temp. Heat gun the head (much safer than attempting to touch it). If that's ok, then its your tractor temp gauge. If that's not ok heat gun each exhaust pipe off of the head. If they are all hot then heat gun the radiator. If one or more of the exhaust pipes is cool then you have a cylinder not firing which dramatically reduces the heat output of the engine. Low temp engines are caused by 1 of 2 things: Not generating heat or displacing heat too fast; either should be found by what Ive suggested.

 

[beenthere]

With his 2 cyl JD 730, losing one cylinder by not firing will be some noticeable.. for sure, for sure.

 

[adventure bob]

Not familiar with the 730, but I would imagine you'd notice a 50% drop in performance. Thought it was a small 4cyl.

 

[beenthere]

Big 2 cyl
TractorData.com John Deere 73 tractor information

And for a pic of Derek's 730, see reply #9
http://www.tractorbynet.com/forums/...where-post4658077.html?highlight=#post4658077

 

[DerekA09]

Ok so I did put the thermostat in water and brought it to boil then let it cool off. It opened shortly before the water started boiling and then slowly closed after the water stopped. So I'd say I should have just bought a heat gun and tested the temp sensor spot to begin with. But oh well had to pull most of that off anyways to re thread the manifold bolts so coolant couldn't seep through. Yeah, if I don't notice losing one cylinder I don't have any business operating that tractor lol And I was worried about increased cylinder wear of not operating at temp. This isn't a parade tractor. It's the only one I have so it's a working tractor.

 

[adventure bob]

I'm assuming that the operational temp of this tractor is between 195 and 205 and if it opened just before boiling (212) then it should be good to go. I usually use a candy thermometer to check actual temp to make sure it meets spec.
So Id move on to the sender and gauge as the issue. I would however put it back to together and double check head temp with a heat gun.

 

[pmsmechanic]

Actually if you have a heat gun there is no need to remove the thermostat to check it. If you measure the temperature of the thermostat housing with the heat gun you can see at exactly whet temperature the thermostat opens and closes. Just throw a garbage bag over the radiator and hold the heat gun on the thermostat housing.... with the engine running of course.

 

[SandburRanch]

If in certain winter weather conditions you see a creamy white mucus looking build up on the dip stick and the filler cap underside you'll know what not operating at recommended temperature does. That's moisture build up in the oil from repeated operation under less than optimal temperature conditions.

 

[beenthere]

Derek
Ran across this link to a JD 730 recently sold at auction in IL.
How a John Deere 73 Can Command an Auction | Agweb.com

 

[DaninOhio]

Put the Gates thermostat in as Cat-Driver suggested for $40, that is what I did on my 70 gas. Still needs to be worked to come up to temp. My 70D warms up faster and has a lower temp stat (170).