Hi, On my '03 3.4l 4dr automatic..in the morning i get a really high idle (around 1500 rpms),until it warms up then its ok..the truck blew a head gasket and it did over heat..but not enough to cause major damage after doing a engine gasket kit, changing timing belt,water pump,thermostat..all is good runs perfect, except when the truck is cold it idles really high until it warms up (minute or so). Did the overheating cause the coolant temp sensor to go bad?? is this my problem??

Thanks

 

No that's totally normal. Everyone's truck does it, you can search for it and find out all about it.

 

^ what he said.. it's fine and nothing out of the ordinary. Mine idles at around 1500 for a good 3 minutes or until I put it in drive or reverse.

 

Wow, Really???..i jus got rid of my 93 4x4 3.0l automatic and it never idled cold that high..maybe 1200 at the most..so i guess i was taking that into consideration plus i thought being the truck overheated (i bought this from a guy who didnt want to fix it) it could have messed up the senors readings..yea mine idles down once i put it in drive or reverse..so the only purpose for the coolant temp sensor is for the gauge reading or does it intermingle with the computer for other adjustments associated with the TPS,etc?

Thanks

 

Like others said before, a cold idle of 1500 is normal. Mines idles at around 1500-1700 on cold mornings, but idles lower after 2-3 mins of warming up.

 

Every car on earth is supposed to do this. Its an automatic choke.

 

Like everyone said, it's normal. Mine idles at 1500 for 2-3 minutes too. The coolant temp sensor does have an effect on the idle (it gives info to the ECU), but it doesn't sound like there is any need to replace yours.