hello ....

ok so i recently bough an 03 a4 with 130,000 miles on it from the original owner whom said they have kept it dealer maintained (never recieved my proof though , lesson learned get everything at that very moment!!)

.. now on to the issue im having

first was coolant flange, replaced that

about a couple days of that being replaced my heat was weak went back got some air out of the lines had it re-bled

now... car would over heat to 3/4 the way and go back down to 1/2
i thought thermostat, my mechanic does not believe so he thinks water pump.. fine i buy all parts was just gnna do the whole damn thing (water pump, timing , thermo, coils and spark plugs (since i was getting a misfire code too) was going to drop it off next week but now tonight the car over heated all the way and didnt go back to 1/2 way point . just wondering if any one had any insight on this i would appreciate it very much

thank you in advance