Vehicles temperature is very slow to heat up

Hi,

That sounds exactly like what is happening. It isn't hard to replace one. If you follow the upper radiator hose back to the engine, it will end at the thermostat housing. Here is a link that shows in general how one is replaced:

https://www.2carpros.com/articles/replace-thermostat

Here are the directions specific to your vehicle. Note that this came right from the Alldata manual and includes pics of the entire cooling system. Just move down to where it says removal. The pics attached correlate with the directions.

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2007 Hyundai Truck Entourage V6-3.8L
Removal and Replacement
Vehicle Engine, Cooling and Exhaust Cooling System Thermostat Service and Repair Removal and Replacement
REMOVAL AND REPLACEMENT
THERMOSTAT

COMPONENTS
pic 1

COMPONENTS
pic 2

REMOVAL

NOTE: Removal of the thermostat would have an adverse effect, causing a lowering of cooling efficiency. Do not remove the thermostat, even if the engine tends to overheat.

1. Drain engine coolant so its level is below thermostat.
2. Remove water inlet(A) and thermostat(B).

pic 3

INSTALLATION
1. Place thermostat in thermostat housing.
1) Install the thermostat with the jiggle valve upward.
2) Install a new thermostat(B).

pic 4

2. Install water inlet(A).
Tightening torque 16.66 - 19.60Nm (1.7 - 2.0kgf.m, 12.30 - 14.47lb-ft)
3. Fill with engine coolant.
4. Start engine and check for leaks.

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Let me know if this helps.

Joe