I collected my 2009 MK3.5 2.0 sport at the weekend. Car is fantastic, just 32k miles and one owner. However, whilst driving 450 miles home to north east of Scotland, I did notice the water temperature never got above the 4 o’clock position (more like 4:30 really) and after some research online I still can’t determine if this is ok or not. Some people report it’s normal, some people say mid gauge (3 o’clock) is normal. With that in mind, will replacing the thermostat make a difference? Again, mixed reports and would appreciate if you can complete the poll.
I would take the opportunity to replace the header tank and coolant since the car is almost 16 years old.
I first thought it was just the odd gauge layout, like the fuel gauge (9 o’clock being 3/4 full, very odd) I was initially very concerned that I’d used half a tank in 80 miles until I realigned my eyes
mine (nc1) sits very low maybe 5 oclock does get to nearly half way if you sit in traffic BUT heater works fine - been like that since i had it about 4 years
See the attached (poor picture) if your coolant temp gauge reads as in that picture then it’s normal when up to operating temp. If it sits any lower say with the heater on full then maybe your stat needs replacing. Heater on or not that gauge usually sits rock solid at the position shown.
The expansion tank exploding in the UK I’ve never heard of, worry if the car is used in much more hot climates than ours, always a first of course.
I changed my expansion tank for a metal one, mainly because the plastic one was discoloured, and the metal one looked better in the engine bay, that’s all.
Thanks for the information Mick, especially on the expansion tank. I read a few articles that mentioned this item regarding preventative maintenance, but thinking about it they were probably more US based which would make sense. Yours does look smart though.
Sounds like I don’t have a problem. It never moved from the 4:30 spot, either in traffic or with the heaters blasting, so nothing to worry about. What were Mazda thinking regarding the dial designs.
Get yourself an ELM327 Bluetooth OBD dongle and install “TORQUE” on your phone.
You can then see real time data direct from the ecu ( including water temp )
If the gauge is stable once the engine is upto temperature it’s probably ok. If it fluctuates and rises if stuck in traffic you may have a dodgy thermostat. That’s not the full story but a reasonable rule of thumb.
Good tip, thanks. Will do that. I assume it should be around 88 degrees. Will report back, although will be a few weeks until I have it back on the road (replacing brakes, detailing etc).
