GX470 is running hot (past half mark)

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Apr 17, 2006
Camp Hill, PA

Troubleshooting: GX470 temp gauge reads hot (past 1/2 mark). The hose that runs from the top of the engine to the radiator was leaking at the thermostat due to a loose clamp. I tightened it and filled the reservoir a few times, with the amount of coolant being lower in the morning (always filled to the fill line).

Video: Radiator opening burbling

Things I've check:
- Oil is clean, no sign of contamination
- No white smoke in the morning
- Idle is fine at start
- Temp doesn't go above the top of the temp symbol on the cluster (see photo)
- Heater works well
- Timing belt/waterpump replaced at 120k (184k now)
- IR thermometer shows 200-204 degrees at the T-stat housing when car is fully warmed up
- Previous owner filled with green coolant, I need to purge it, but won't have time for another few weeks

Tried burping the system by leaving the radiator cap off while the car was parked on an incline and let it warm up to the half-way mark. The coolant gurgled for a bit, but finally calmed down, let it run again without issue.

When I'm driving, the temp gauge stays slightly below the middle level. If I stop, the gauge reads on top of the temp signal.

The timing belt and water pump were replaced with an Aisin kit. The fan appears to be running just fine, and increases in speed when throttle is increased.

My new to me 2006 truck was low on coolant. it ended up being the throttle body coolant hose that goes to the right side head from the TB. Part number 1626150140. Not only that but the fitting popped out of the throttle body when I pulled the old hose, had to "reinstall" with a hammer lol.

There was a huge amount of dried coolant under the throttle body, kind of like an icicle. I suggest you check around the area if you cant find a leak easily, it may be evaporating faster than you can see it.
Original Radiator ? These are pretty notorious for for micro cracks around the cap area . Took me awhile to figure out exactly where my leak was and the only overheating i had was when i first realized i was losing coolant . After that I was on top of it daily until i replaced radiator , hoses , thermostat and thermostat housing . System has held and performed flawlessly after that . Make sure to drain your block as well as your old radiator .
buy or rent the tool to pressurize the cooling system cap then it will force the leak out.

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