L2900 gst

[string1946]

Hi everyone. I have a Kubota L2900 GST I bought new in 1997. When I first start it, the fuel and temp. gauge appears to work correctly but after running the tractor for a while (30 to 60 Minutes or so) the gauges start to creep up and after awhile they are pegged out. Seems like something common to both gauges is heating up and causing this problem. Does anyone have any idea where I should look first. Thanks.

Larry

 

[hodge]

I don't have a direct answer to your question; are you certain, though, that the two are linked? I say that because I would hate for you to cook the engine because you have a cooling problem, and assumed that the gauge was faulty. I have a Bobcat skidsteer that runs hot on the gauge. It goes to just past the green zone within 5 minutes of startup. I didn't want to just assume that it was a gauge/sending unit issue, so I used an infrared thermometer to check the block, manifold, coolant, coolant hose, etc.- when up to temp, I checked all over the engine, and it wasn't hotter than normal. Point being, I would double check, so that it is in fact the gauges.
Welcome to OTT, and hopefully someone will have a direct answer for you.

 

[string1946]

I don't have a direct answer to your question; are you certain, though, that the two are linked? I say that because I would hate for you to cook the engine because you have a cooling problem, and assumed that the gauge was faulty. I have a Bobcat skidsteer that runs hot on the gauge. It goes to just past the green zone within 5 minutes of startup. I didn't want to just assume that it was a gauge/sending unit issue, so I used an infrared thermometer to check the block, manifold, coolant, coolant hose, etc.- when up to temp, I checked all over the engine, and it wasn't hotter than normal. Point being, I would double check, so that it is in fact the gauges.
Welcome to OTT, and hopefully someone will have a direct answer for you.

Thanks for the reply and the welcome. No I don't know for certain that they are linked. I guess I just assumed because they pretty much move together. (Yeah yeah I know.) Next time I run it I'll take some temp reading while the gauges are looking normal and them more reading at the same location as the gauges move up. I did check the coolant and its still full so its not getting hot enough to boil it out.

 

[string1946]

I'm in the process of changing out all the fluids in the tractor so while I'm doing that I think I'm going to go ahead and change the thermostat since thats about the only thing I can think of that would make it run hot other than a collasped hose. I suppose that if it was getting hot that could have made the fuel gauge sending unit malfuction.

 

[Stumpy]

Make sure the rad is clean too. They can get clogged with grass and other debris. I agree with Hodge, make sure its not overheating before assuming its a gauge problem.

 

[string1946]

Thanks Stumpy. I did that yesterday. It has a mesh screen in front of the radiator. I pulled that out and cleaned but wasnt much on it but some weed seeds. Then I use a hose to flush the radiator from front to back and it seemed to be clear. Order the thermostat so maybe I can put it back together next week. I have the old stat out and could put it in hot water and see if it works but the new one is on the way so will just wait for it to get here. Anybody think of anything else for me to check let me know. Thank you all very much for your help.

Larry

 

[string1946]

Ok now for an update. I have clean and hosed out the outside of the radiator, drained the coolant, flushed clean water thru and put in new coolant, replaced the thermostat with a new one but the same 71C/160F. Then I started the tractor and just let it run. The fuel gauge came up to maybe 1/3 of a tank and then slowly dropped to E. I check the tank and its over half full of fuel. After about 15 minutes the temp. gauge was peggged. Over the next 15 minutes or so I checked everyplace I could get to with a IR thermometer plus the cap over the thermostat and the return hose. The hottest spot on the block I could find was around 165, thermostat cap 125, return hose 95. It doesn't seem to be running hot but I don't know how to tell for sure. Not sure what to check next. Hope someone here does. Thanks for reading this anyway.

One other thing. I did a search on here and found a older post by someone with the same problem with their L2900. It was never resolved in the post but one suggestion was to run it up to temperature and check the temp. of the water in the overflow tank. I ran it for bout 10/15 minutes and the gauge was pegged then I ran it another 20 minutes and checked the over flow tank and it was around 100. I don't know if thats long enough to be valid but I hate to run it longer till I know whats going on.

 

[string1946]

Ok it appears I have found my problem but I intent to watch it close for a few days to make sure. My tractor has a temp. sending unit in the cover that is over the thermostat just below the outlet hose to the radiator. There is another temp. sending unit on the outlet side of the radiator just before the hose hook up returning to the engine. The wires to that second unit are bundled with the headlight wires and at some point when I pulled the grill off to get to the battery either I pulled those wires off and forgot about it or they just pulled loose. Anyway after I hooked them back up the temp. gauge moved but just barely after running the engine for an hour. Thanks to all that made suggestions.