Hi, I'm a new member.
Who among you has detected the temperature of the 4.2 V8 aspirated engine with the OBDII scanner?
Obviously both with the car stationary with the engine running and while traveling.
If you have done so, can you tell me what your results are?
Thanks

 

Mine varies from the upper 190s to 215ish, depends on ambient temps and how I’m driving. The higher temps are when idle after driving.

 

Hi using the TORQUE app on my phone in Celsius moderate speed about 90 degrees, faster hot day up to 95.

 

For F guys simplified for brain work, that's {(2C) -10%} + 32 = 194 and also 203.

 

The original thermostat on the 4.2L was 92C, and now the replacement thermostat housing by URO has a 91C in it.
Long traffic lights will see the coolant rise to 95C with the Evans racing coolant, then it drops back down quickly on the green light.
By the way, the cabin heating system starts up at 50C.

 

I have placed temperature gauge to my Android rear view mirror via obdlink. In a traffic or at idle it usually not more than 95°C, when cruising ~88-90°

 

Thanks everyone for the info.

I looked at the service manual.

It doesn't specify any operating temperature.
I think it should be around 95°C (203 F).

The manual says that:
<< When the temperature reaches 82°C (180°F) the main thermostat begins to open allowing coolant to circulate through the main radiator. As the thermostat progressively opens (fully open at 95°C (203°F)), the bypass valve progressively closes forcing any coolant through the heater or radiator. >>
The safety limits given in the manual are as follows:
1) ENGINE TEMPERATURE HIGH
Amber warning triangle illuminated in LCD at temperatures of between 118.0°C (244.4°F) and 119.3°C (246.8°F).
2) ENGINE OVERHEATING
Red warning triangle illuminated in LCD at temperatures of 119.4°C (247°F) or above.

 

Let me explain my problem:
My OBDII scanner detects a temperature during the trip of 98-102°C (205-216 F).
If I stop the car with the engine idling the temperature quickly rises to 105-108°C (221-227 F) and within a few minutes it reaches 113-115°C (236-239 F) even if the fan is turned on at maximum.
The fan turns on at about 95°C (203 F) and at 103°C (218 F) it reaches maximum speed but is unable to contain the temperature.

If with the car stopped with the gear in neutral I accelerate to about 2000 rpm for about 20" the temperature drops to 90-93°C.
If I release the throttle the temperature starts to rise again.

 

From the workshop manual for the 4.2 = "the thermostat starts to open at 80°C (176°F) to 84°C (183°F) and is fully open at 96°C (205°F)."

 

From my own experience I suspect you have a cracked plastic thermostat housing as you are running quite hot. This allows the coolant to partially bypass the radiator and should be rectified ASAP. Many threads here about this.
Good luck!