For 1990-2009 cars

# Engine Temperature Guage Reads Up to 20 F (11 C) Higher with Heater On

Subject: | Engine Temperature Gauge Reads Up to 20 F (11 C) Higher with Heater On

Models: | 2008 Pontiac Solstice, Solstice GXP

| 2008 Saturn Sky, Sky Redline

| 2008 Opel GT

| 2008 Daewoo G2X

| with 2.0L Engine (VIN X - RPO LNF)

| or 2.4L Engine (VIN B - RPO LE5)

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

### Condition/Concern:

Some customers may notice the temperature gauge increase as much as 20 F (11 C) when the heater is on. Upon inspection, no DTCs will be present, the cooling system will be full, and the engine is not overheating. A technician may also notice that the coolant coming from the radiator is very cool (no matter how hot the engine gets) and that the lower radiator hose may be relatively cool too.

### Recommendation/Instructions:

If the SI diagnostics do not isolate a cause for this concern, no repairs should be performed because this is a normal operating characteristic that occurs as a result of normal thermostat operation with the heater on.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.