I have an odd problem going on with my coolant gauge. It acts fine (no jumping on startup) until I'm idling in traffic on a hot day. It's usually a little above the 210 mark, but then it will sort of jump into the red area and hang there until I kick the heater on and get moving again. It doesnt' slowly drop though, it sort of jumps again back to a little above the normal area. I'd say it visually jumps about at least 1/8 of an inch, maybe a quarter. It's only from the red to the normal area or vice versa.
Can anyone guess what part is more likely to be at fault considering the circumstances? Originally I thought the sender, but after searching and reading, it seems like if the sender (or the gauge) is going, it would be a lot more erratic or unreliable.
In case it might be related: my oil gauge has been acting up off and on for a couple months, too. When accelerating on the highway it jumps all over the place between the halfway mark and the right hand side.
Can anyone guess what part is more likely to be at fault considering the circumstances? Originally I thought the sender, but after searching and reading, it seems like if the sender (or the gauge) is going, it would be a lot more erratic or unreliable.
In case it might be related: my oil gauge has been acting up off and on for a couple months, too. When accelerating on the highway it jumps all over the place between the halfway mark and the right hand side.