Before I set on to replace my NC 2.0 thermostat I would welcome your thoughts on the symptoms. I have suspected t was running a touch cool for a while and sometimes the guage shows lower than normal…but not always.
On a run with obd connected to display, engine seems steady around mid 70’s degrees.
Freewheel downhill and temp drops to upper 60’s
Stationary, with increased tickover, the car peaks at 100 degrees then suddenly drops to mid 90’s as fan kicks in.
So, with ambient temperature around 20 degrees, if the car being driven is normally around md-seventies am I using excess fuel and is replacement thermostat the answer?
Any thoughts appreciated before I go on a bit of a tour next week
Most of what you are stating about the temperature sounds about right.
I would say that the car’s coolant when warm should range from mid 60s upward. Fan seems to be cutting in at the right time but unclear as to when thermostat is opening - perhaps difficult to tell but should be around 80 - 85 degree celsius I think.
If you are saying that the thermostat is opening at 70 then I would say that is at least 10 degrees too early.
Thank you…sounds like we’re on similar wavelength on this. The replacement thermostat is set at 82 degrees so I’m pretty sure it is running on the cool side.
Will set about changing it in the next couple of days and check the outcome.
My 2008 car had the later thermosat but some of the earlier pre facelift cars have a thermostat that had a design change to improve its operation therefore it is a good call to replace an earlier thermosat.
All done and steady 88 degrees on the obd meter in similar driving conditions to yesterday’s where the temperature varied so much.
Thanks guys
Oh and around two to three hours is a good call…most difficult part was reattaching the new thermostat being very careful to not cross thread very inaccessible bolts…and also getting all air out of the system afterwards.
To resurrect this im going to get my stat changed on my NC as it now rarely gets to half way and on a run more like 1/4 way up or less. Had a flush and replaced the longlife F22 last year, stat seemed ok then but got worse over winter. Question is will all or most of the F22 be lost ? Still have 4 ltrs left and wondering whether i need to get another 5 ltrs.
I had my coolant changed the year before I changed my stat. I collected the drained coolant in a clean container then passed it through a gauze to collect the very little debris in there and reused it.
If you have some left from the previous change then great to top up.
Thanks Mick, sounds like a plan. Cars only done prob less than 1000 miles since F22 changed. As you say strain and save a bit in case 4ltrs isn’t enough. Nearest Mazda place for the F22 is a 40 mime round trip.
My mechanic friend is doing this one as believe throttle body etc to disconnect for access which is tight anyway. Had enough swearing changing the aux belt this week
Got mine from here https://www.opieoils.co.uk/p-91277-integral-thermostat-mahle-ti-202-82.aspx
There are two types fitted to the NC depends on vin numbers. The one in the link has the longer neck on the main hose connection, yours may have the short neck. I just trimmed the hose down on the car about 30mm for a perfect fit.
Yes it’s a faff getting at it but obviously well worth it and a must do job.
