Recently I installed a aftermarket temperature but not the supplied sending unit. My operating temperature is around 220. Checked it with the heat gun and it’s at 180. I’m hoping swapping the sending units out will calibrate the gauge. Any thoughts….
G1800 temperature gauge
- Thread starter Orangerider
- Start date
There is no reason to believe you can "mix or match" after market parts with original within a system. If you use the after market gauge with its supplied sending unit they should work properly together. Since your heat gun is measuring an external temperature and the sending unit is inside the block You may not get precisely the same indicated temperature but it should be pretty close. You should also allow for accuracy differences between the two, that is what is the percentage of error for each. Calculate the worst case extremes and you should be within that.
85Hokie
Moderator
Staff member
Lifetime Member
Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
The trick with different sending units and different meters is WHAT electrical resistance the meter reads.
If you ground the meter lead - it should peg hot.....so at the highest resistance, the meter reads cold.
Each meter will "read" a range of resistance(s) ......... so it really could be a difference between the two.
Here is a bit of info that may help you :
https://www.autometer.com/blog/faq-...your ohm meter, measure,ohms at 266 degrees F.
Last edited:
kubotafreak
Well-known member
Equipment
GRAND l6060, L3560, B6100, gr2100, tg 1860, g1800, g1900, g2160
Many mowers that size have a “horn” to alert of over temp. The factory gauge is kind of a gimmick. Most mowers do not have them anyway. So putting a better quality gauge is a good undertaking… With that said. Ive found that model specifically needs seasonal radiator shroud dissembly to get all the blockage out behind the shroud.
G1800 has a horn too. They start going off when the engine is on the verge of seizure. Up on the thermostat housing is a "sender" with a wire going to it. Remove the wire and ground it with the key on. The horn outta blow. If not there is probably a wiring problem, as G series mowers were notorious for wiring issues of all kinds.
Factory temp gauge works great, when it works. I like the factory look-those mowers were way ahead of their time, and great mowers (except the wiring) so long as they were maintained. Both of mine had temp gauge issues, I could reach up and "pop" the top of the dash with my palm and the gauges would come to life, indicating that there was a connection issue on the board somewhere. I tried removing the wires and cleaning all the contacts and that fixed the fuel gauge, but not the temp. Replaced that gauge assembly with an ebay one, and then the fuel gauge quit (temp still works). I knew how much fuel it used (ran all season on a tank of diesel) so I didn't worry about it. New owner can deal with it. The other one still don't work, my dad uses that one and loves it. Actually come to think of it, it's time to service it.
IR temp guns are never accurate to measure engine temp. they only measure surface temp which is often quite a bit cooler than actual
Factory temp gauge works great, when it works. I like the factory look-those mowers were way ahead of their time, and great mowers (except the wiring) so long as they were maintained. Both of mine had temp gauge issues, I could reach up and "pop" the top of the dash with my palm and the gauges would come to life, indicating that there was a connection issue on the board somewhere. I tried removing the wires and cleaning all the contacts and that fixed the fuel gauge, but not the temp. Replaced that
coolant temp, and actual coolant temp is what you want to see. I'd like to see EGT, fuel, water, oil temp, oil pressure, and boost but we can't get "too" carried away. The G series didn't have a turbo. Mine did for a little while but it didn't do anything to speak of, just cleared up some exhaust smoke and that's about it. No noticeable power difference. 7-10 psi depending on load. WGA opened at 10. Could have been better with the right pump but I wasn't about to spend that kind of money on a $200 lawn mower.
use the sender that's made for your temp gauge. The port in the side of the head (rear, LH side as I recall) is tapped 1/8-27 NPT, and that's where you should measure from as it's the hottest part of the engine. Some of the aftermarket gauges don't have a 1/8-27 NPT fitting, or a way to make it work, so you may have to do some searching or get real creative.