I have a 1998 V6


Recently, I replaced the water pump and flushed the coolant. When I let it idle for 10 minutes or so, the temperature climbs up to a mark under halfway (~160 deg). However, once I get moving, the temperature starts to drop to where its nearly at the lowest mark (looks like ~120 deg). Granted, it is 25 deg F out, but something seems off.

I know it could be a bad thermostat, but I feel like that doesn't explain why the engine temp will climb when idling, right? It goes up to almost halfway when idling, comes down when moving.

Ever since getting the car almost 2 years ago, the temp gauge has rarely been at perfectly halfway (210 deg). It usually shows a mark colder (160-170). On a super hot day sitting in traffic, it might creep up to 210, but once I get moving, it generally drops back down a mark.

Not sure if anyone else has experience with something like this, any help would be appreciated.


EDIT: Also, if you do suggest me replace the thermostat, should I get a 180 or 195 deg? I live in NJ, so temps now are in the 20s but it could hit 95 in the summer! What is stock thermostat that came with the car?

 

It is the correct symptom pf a stuck thermostats. The reason it get warm just idling is because there is no air flowing through the radiator until the fan kick on.

Use the stock 195 unless you plan on tuning the engine.

I don't know how long you have owned the car but if the previous owner installed a fail safe thermostat it job is to stick open if the car ever over heats. Once they open because of overheating they never close.