1999 Auto V70 Engine Runs Like a Pile of Rocks

[Luxobarge]

Originally Posted by Chris_Rogers

Sorry to disagree but the engine ECU will always start the fan when the temperature sesnor is disconnected.
The op said the problem starts when the gauge is at 3 o'clock this suggests to me the mixture is weak at full engine temperature, probably due to an induction air leak.

Fair comment. Still find it odd that the fan doesn't come on at all, but if the temp guage is sitting nicely at 3 o'clock then yes, that would seem to indicate that the temp sensor is doing its thing at least roughly right.

If it is indeed running sufficiently weak to give rough running, then there should be one or more codes thown. I'd recomment reading the code(s) to be sure.