Overheating at Speed

[Leedogs]

Hi all, Back again lol

Have a recurring overheating issue now that only happens when going 80+. Temp will build and sit around 3/4 of the way up the temp gauge if doing highway cruising, it will rise if she has to do any hard work up hills etc, but temp will fall to almost normal when car is stationary.

Have already replaced both Coolant temp sensors, neither of which seemed to help. Coolant flush similarly not assisting and radiator is relatively new, replaced in roughly September 2021.

I find that running the A/C drops temp to a manageable level, not quite percect but safe.

Also while I'm here, revs refuse to register on the tacho, even now with a IFS Bypass, probably a crispy wire somewhere down the track.

Any and all ideas welcome, Summer will not be fun lol

[bjk]

Hopefully it's not a dud radiator, but I had similar symptoms when mine was clogged years ago. Maybe replace thermostat and rad cap since they're fairly accessible/affordable. Possibly worth checking your fans are turning on? Though if it's still hot at hwy speeds when they're not really doing anything, likely not the culprit. Good luck!

[Leedogs]

Thermostat was done in May 2021 and tested again in April of this year. Hopefully I haven't baked it since then. Same with rad cap, although I'm about to take her out to Bathurst, if she doesn't like that so much, will likely start from square 1 again.

Heater matrix is slightly leaking if that could be a factor? That or a dodgy radiator are looking likely for me