Although it bothers me to suggest it, I'd do two things in this case: Coolant temp sensor Thermostat They're in the same housing and relatively cheap. Get new gaskets too. Well, it did it again after sat for 8 minutes idle, so I'm going to have to find the sensor and thermostat, then figure out how...

Which fan is running all the time? The AC fan will run if the AC is switched on but the radiator cooling fan should not be on all the time. Temp sensor / thermostat are the likely candidates. The radiator cooling fan, once that gauge tries to wrap itself against the right stop. It does stop, eventu...

Interesting thoughts, now I'm not too certain if they checked the thermostat, or the temp sensor. Just to 'mix things up' a little, since changing the front Lambda sensor (the same garage fitted a generic one for the turbo model, rather than the N/A version) I don't appear to have this problem arisi...

Coolant is at the same level it was since a major dealer service two years ago. Coolant temp is actually low, because it keeps the fan running all the time (guess I'll be replacing that before too long if I can't track this problem down.) No bubbles in the coolant reservoir, the pressure seems fine ...

Possible earth loose? Looking at the wiring diagrams the instrument panel etc is on both a different live and earth to everything the engine would otherwise need to continue running. Either that, or a fault in the instrument panel itself (not too certain where the control module for the headlights i...

Is there a more general board to post this query on? I'm guessing it probably not limited to just a possible S80.

So I have this rather interesting (and now more annoying than worrying) problem with the coolant temperature gauge. Reproducing it isn't easy but tends to be a case of letting the car sit at idle for about 5-10 minutes while touching nothing. What happens is, well, the gauge reads as if a thermonucl...

Locks on the S80 must be a 'thing' - I sometimes have the issue where it just won't lock the doors at all (either with remote, or the key.) - They lock, but then all pop up again. My longest lasting solution was to remove the battery negative for five minutes, then manually locked the drivers door a...

Just in case anyway, this may help?

https://www.matthewsvolvosite.com/forums ... =1&t=10144

As for it being the MAF, surely that would be throwing a code?