MKS temp gauge issue.

[ChaudMasterFlex]

I have a 2014 MKS ecoboost and I’m having an issue where the temp gauge randomly drops while driving. It never goes above the “normal” spot, but always drops with no rhyme or reason. Sometimes it’s just a single step down, other times it drops quite significantly. Temps seem normal number wise (cruising 194-200, and jump to 209-210 when idling). I put a new 170 t-stat in yesterday and spent about an hour trying to bleed it (hoses weren’t collapsed, both were hot). Felt like I lost more coolant than I put back in too. It’s doing the same thing with the new t-stat (feels like it’s doing more tbh). Also, water pump, chains, guides etc were changed 1k miles ago. It’s driving me nuts, any ideas?

[SHOdded]

certainly could still be air pockets but havent seen this erratic behaviour in a related way. how have you been bleeding the system. you can use a lisle spillfree funnel to help with the process. make sure that while idling/parked, the reservoir is the high point of the cooling system. parked on a curb or sloped driveway or ramps on that side will help.

battery voltage weakness could potentially cause this type of issue. or pest-damaged wiring.

[ChaudMasterFlex]

certainly could still be air pockets but havent seen this erratic behaviour in a related way. how have you been bleeding the system. you can use a lisle spillfree funnel to help with the process. make sure that while idling/parked, the reservoir is the high point of the cooling system. parked on a curb or sloped driveway or ramps on that side will help.

battery voltage weakness could potentially cause this type of issue. or pest-damaged wiring.

Battery is new. I've been bleeding it with the cap off and a funnel. It's just driving me nuts.

[Thomks]

The thermostat is just a valve for coolant to enter, it reaches a certain temp, ie. 170