Sensor problem?

[garfield_08]

Good day!

We have a diesel mitsubishi adventure. Recently, napansin ko na tumataas yung temperature reading ko sa guage during traffic. normally it stays sa half-level lang with AC on. di naman kumukulo yung tubig sa reservoir (50:50 coolant mix) and i already flushed the system last week. tumataas siya ng 3/4 sa guage during traffic, nakakakaba lang kasi baka mag-overheat. pero sa highway ok naman yung reading, slightly above the halfway mark. ok naman yung radiator fan clutch, may resistance naman kapag pinihit when the engine is cold. medyo malabo yung chance na mag-overheat basta basta since i only drive about 10km to my workplace.

Then, i discovered one morning upon starting the engine. while waiting for the diesel to warm up, i noticed the temp guage rise to 1/4, the key in the "on" position.

this puzzled me since the engine wasn't even running yet, and the temp gauge already rising up . any ideas on whats wrong with my ride? could it be the temp sensor? or the gauge itself? if so, where could i find the sensor?

TIA.

[niky]

Sure the car wasn't used the night before?

Usually, if it's higher in traffic than when running (and no overheat), that indicates a problem with the fans or the water pump.

If the readings already move when the engine is ice-cold, then it could be a sensor issue. The sensor is usually located near the thermostat, upper radiator hose.

[garfield_08]

Sure the car wasn't used the night before?

Usually, if it's higher in traffic than when running (and no overheat), that indicates a problem with the fans or the water pump.

If the readings already move when the engine is ice-cold, then it could be a sensor issue. The sensor is usually located near the thermostat, upper radiator hose.

the car wasn't used the night before, so it has ample time to cool down.

haven't considered the waterpump yet though. im just anxious that the temp gauge moved up without the engine running, 1st time nangyari kasi sa car namin to, dun sa ibang previous cars namin di ko siya naexperience na ganun.

so i'll be checking the temp sensor then. sana nga yun lang problem.

thanks niky.

[EVO-V]

If I remember correctly that 4D56 under the hood drives the radiator fan via the crank. This is unfortunately a cost-cutting measure by Mitsubishi given electric fans do a much better job in regulating temps in a diesel engine.

If you're idling in traffic and you're encountering temp spikes, it may do you well to check your cooling line.

If the engine is cold and the sensor jumped from ACC ON you may have an electrical issue, could be grounded. Thermocouples measure the electrical resistance that goes through the sensor. The higher the temp the more resistance.

Also 50-50 coolant mix is actually poorer in conductivity than a 30-70 coolant-water mixture. Your typical glycol coolant does not increase water's capability to remove heat, it actually decreases it in favor of raising its boiling point apart from preventing nasty things from happening inside your engine.

You may also want to look at blowing some air through your condenser/radiator assembly. Maybe a quick shampoo, wash, and then dry too. Little things cheap things that help your cooling system. But do NOT pressure wash these things beyond 1 bar. They tend to deform.