Can you sneak a ring spanner in over that sender? Might be enough swing space for it to loosen it.
12HT-swapped 1988 HJ60 in Melbourne
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- #42
Unfortunately not - the AC bracket is in the way
Sorry to say that i had to replace mine and the only way was to remove the compressor.
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- #44
Bummer. Suspected that might be the case. Any tips or things to watch out for?
The sensor screws into the bottom thermostat housing.. if you have a gasket (or are happy to cut, or buy, one) you could just remove the lower thermostat housing to deal with this.. ps you're confident the sender is faulty?
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- #46
I’d considered that. If it’s really stuck and needs to be drilled out (I swear the person who installed this one used loctite instead of antiseize…) that might be easier with the thermostat housing off anyway
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Have you tested the sender? The manual shows a resistance vs temperature range. There's not much to go wrong with these sensors. Have you tested the gauge in the dashboard?
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- #48
I’ve tested the gauge and it responds as expected when I bypass the sender with resistors of appropriate rating.
Unfortunately I can’t test the sender itself because the diagnostic process for that involves removing it from the thermostat housing, which is my problem
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If the resistance is roughly correct for the ambient temperature, I would be checking the wiring before removing the sender.
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- #50
When I tested the gauge I did it from the wire at the sender, so everything from the sender to the dash seems to be working. Good thinking RE testing the resistance of the gauge at ambient, I’ll try that tomorrow and report back
Also keep in mind that diesels don't make much heat until they are working pretty hard.
I'd recommend getting a cheap infrared temperature gun and seeing what your actual temperatures are. It is probably fine.
My diesel will usually run about 1/4 of the way up the temp gauge most of the time, and will go to 3/4 when pulling a trailer at high altitude uphill.
what the chief said. I've driven an hj61 for 15 years (2 different vehicles) and the temp guage ALWAYS hangs out at the bottom line of the "okay/operational range" it will barely move into the midrange of the gauge when doing steep inclines on the highway.
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- #53
My gauge sits at ‘cold’ even after driving for hours (barely rises above where it sits when the car is off) and will only hit about ¼ under heavy load, which makes me suspect something is wrong somewhere
Could also be that the thermostat is stuck open and she’s just running that cold I guess?
POPO AGIE
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Up here in the colder regions some diesels like the Cummins 6B ran cold and complaints of not heating the cab. My experience has been all the diesels I have had Navistar 7.3 IDI, Cummins 5.9s and 6.7s all warmed up enough to keep the cab warm and sub 0 conditions.
Check your thermostat it may be opening too soon.
Check your thermostat it may be opening too soon.
considering you don't know whether this is the OG, 38-year-old thermostat or not, it's not the most difficult thing to rule out next. and then you know you have a new thermostat.
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- #56
Have ordered a new thermostat, thermostat cover gasket, and thermostat to engine block gasket. Hopefully with the whole housing off I can get to the sensor more easily (I have a new one, so I may as well put it in) and that should fix it.
I know there’s a rubber o-ring that sits on the thermostat - is that included with the genuine thermostat (90916-03026) or does it need to be ordered separately? I couldn’t find a part number for it
I know there’s a rubber o-ring that sits on the thermostat - is that included with the genuine thermostat (90916-03026) or does it need to be ordered separately? I couldn’t find a part number for it
There is no rubber o-ring for the 2H/12HT thermostat, just the paper gasket.
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- #58
I thought there was one that went on the thermostat itself, inside the housing
Definitely not.. you just need a new thermostat and a paper gasket, no other parts.
From what you have said, I think your gauge and thermostat are working as they should. In cold weather mine barely moves - with coolant temps around 82-84, but towing my boat with aircond on in mid 40 degree heat in the north west of Western Australia the gauge will move up to the middle and Coplant temp is around 100degrees celcius…