445 Temp gauge doesn't show any life

[wwivhobbit]

Bought another 445 and like my last one needs a lot of TLC to get it back to its former glory. Maybe it should list the trouble spots and go from there?

1. Runs rough, or surges, unless at full throttle. The plugs were nasty and caked with soot so i put new plugs in with no discernable difference.

Update: Today I pulled the new plugs out after letting it run for awhile (15 minutes) to warm up to do an oil change and the left plug was already pretty black, and the right one still looked like new. My first thought was maybe rings getting worn (1750 hrs on meter) so did a compression test and had 150 psi on both cylinders. I put the plugs into the caps and grounded each on the head and could see spark but it looked to be intermittent. I've read so much about rough running coming down to bad coils that I'm tempted to buy new ones but the cheapest oem ones i can find are over $80 which is too much for a test!

2. No visible life in the Temperature gauge. I started it and let it run for a good 20-30 minutes and the gauge never seemed to move. Checking things over the top radiator hose was good and warm but the bottom one was cold still. This tells me that the thermostat must not have opened (yet), or the water pump wasn't pumping?

So far, other than the glass cover over the gauges being cracked and these 2 things I think it might be a very serviceable lawn mowing machine for my 2 acres of very hilly lawn!

 

[oldnslo]

If my memory is correct service manual has a procedure for checking the temp sending unit. I believe it has an ohm range from cold to running temp.

Another thing to check is the instrument cluster ground connection(s). This may or may not affect the fuel gauge.

 

[beenthere]

Did you start another duplicate thread for this problem?

 

[wwivhobbit]

Did you start another duplicate thread for this problem?

I don't believe so. I started 2 different threads. One was about an overheating problem on my old 445, which has been rectified I hope. The other is about the most recently purchased 445 with 2 different problems. Rather than clutter up the forum with updates i just edited my original post to add updates. Is that not appropriate? If that's not the norm here I'm willing to conform as long as I'm told

 

[rScotty]

Bought another 445 and like my last one needs a lot of TLC to get it back to its former glory. Maybe it should list the trouble spots and go from there?

1. Runs rough, or surges, unless at full throttle. The plugs were nasty and caked with soot so i put new plugs in with no discernable difference.

Update: Today I pulled the new plugs out after letting it run for awhile (15 minutes) to warm up to do an oil change and the left plug was already pretty black, and the right one still looked like new. My first thought was maybe rings getting worn (1750 hrs on meter) so did a compression test and had 150 psi on both cylinders. I put the plugs into the caps and grounded each on the head and could see spark but it looked to be intermittent. I've read so much about rough running coming down to bad coils that I'm tempted to buy new ones but the cheapest oem ones i can find are over $80 which is too much for a test!

2. No visible life in the Temperature gauge. I started it and let it run for a good 20-30 minutes and the gauge never seemed to move. Checking things over the top radiator hose was good and warm but the bottom one was cold still. This tells me that the thermostat must not have opened (yet), or the water pump wasn't pumping?

So far, other than the glass cover over the gauges being cracked and these 2 things I think it might be a very serviceable lawn mowing machine for my 2 acres of very hilly lawn!

1. For better spark, replace the carbon fiber core spark plug leads with good copper wire leads and insulated metal connectors. I'm betting you'll be surprised. The problem is finding good copper spark plug cable today when most replacement are the RF suppression type. I have an old roll of good spark plug wire from NAPA from years ago & a box of "sparkies" for the plug ends.
You can also find good cable at hot rod shops and vintage motorcycle shops.
BTW, any 12 volt coil will work most motors. OEM is rarely necessary. Worth a try.

2. I've never been able to figure out what was happening by comparing the hose temperatures that way.
The problem is that the upper hose has a bypass either in the hose connect or thermostat - and that passes enough coolant to keep the thermostat closed until the motor is working hard.
I test the thermostat by putting it in a pan of water along with a candy/meat thermometer and heating on the stove. Opening temp is printed on the thermostat. Most open at 180/190 F.
Water pumps will go bad by leaking, but hardly ever stop pumping. If they rotate, they usually pump - even though you often cannot see coolant moving even when looking in the radiator.
Twenty bucks will buy a replacement temp gauge and sender from the auto shop. That's what I do.
Luck,
rScotty

 

[wwivhobbit]

1. For better spark, replace the carbon fiber core spark plug leads with good copper wire leads and insulated metal connectors. I'm betting you'll be surprised. The problem is finding good copper spark plug cable today when most replacement are the RF suppression type. I have an old roll of good spark plug wire from NAPA from years ago & a box of "sparkies" for the plug ends.
You can also find good cable at hot rod shops and vintage motorcycle shops.
BTW, any 12 volt coil will work most motors. OEM is rarely necessary. Worth a try.

2. I've never been able to figure out what was happening by comparing the hose temperatures that way.
The problem is that the upper hose has a bypass either in the hose connect or thermostat - and that passes enough coolant to keep the thermostat closed until the motor is working hard.
I test the thermostat by putting it in a pan of water along with a candy/meat thermometer and heating on the stove. Opening temp is printed on the thermostat. Most open at 180/190 F.
Water pumps will go bad by leaking, but hardly ever stop pumping. If they rotate, they usually pump - even though you often cannot see coolant moving even when looking in the radiator.
Twenty bucks will buy a replacement temp gauge and sender from the auto shop. That's what I do.
Luck,
rScotty

Thank you! Brother came up and we got ambitious and took the gauge cluster out of both 445's and did some swapping and testing. My original 445 had a fuel gauge that's never shown any life and my most recently purchased 445 has a fuel gauge that seems to work and a dead temp gauge. Well, putting the "new" cluster with working fuel gauge in the old 445 shows a working temp gauge and non working fuel gauge, so it appears that on that tractor its the fuel sending unit that's not working, and by having life in the temp gauge on that tractor it tells me that that gauge is fine. Now, with the "old" 445 gauges in the "new" 445 the fuel gauge comes to life but no movement of the temp gauge, so that confirms that the fuel sending unit is bad on the "old" 445 and the temp sending unit is bad on the "new" 445. Sure helps to have 2 identical tractors to exchange parts for diagnostics! I put the new temp sending unit in the "new" 445 but waiting on a new thermostat now so I can button it up and try it!

 

[Spanner]

Temp sender could be fine on both engines. Could be a wiring fault on your new machine.
Have you checked for continuity (or grounding, as per Oldnslo's suggestion) ?

 

[wwivhobbit]

Well, i put a new temperature sending unit in the new tractor and it shows life! That tractor still seems to run much cooler than the one i had first and they both have the same thermostat in them now. I had read that the older 445s used a 160 degree thermostat but John Deere no longer sells that one? Anyway, i was able to find new 160 thermostats and now they both have those. As far as the fuel gauge on the older 445 goes I pulled the fuel pump out and the whole rod and float are missing from the sending unit! I stuck a piece of wire into the round thing that the float rod is supposed to be and rotated it and the fuel gauge goes up and down so i know everything works at least! I just need to find a float rod and float or fabricate something at some point when i get more pressing jobs caught up on. I inquired about a new one from John Deere and $3-400 is way to rich for my blood

 

[Racer4]

Well, i put a new temperature sending unit in the new tractor and it shows life! That tractor still seems to run much cooler than the one i had first and they both have the same thermostat in them now. I had read that the older 445s used a 160 degree thermostat but John Deere no longer sells that one? Anyway, i was able to find new 160 thermostats and now they both have those. As far as the fuel gauge on the older 445 goes I pulled the fuel pump out and the whole rod and float are missing from the sending unit! I stuck a piece of wire into the round thing that the float rod is supposed to be and rotated it and the fuel gauge goes up and down so i know everything works at least! I just need to find a float rod and float or fabricate something at some point when i get more pressing jobs caught up on. I inquired about a new one from John Deere and $3-400 is way to rich for my blood

Check the tank. The float and rod might still be in there somewhere.

 

[wwivhobbit]

Check the tank. The float and rod might still be in there somewhere.

I haven't drained the tank and shook it but did fish all around down in it with a couple different magnets and couldn't pull anything out. Someday I'll get serious about it and try again. Thanks!