danA6

Thank you for the suggestion Gareth. I’ll have a look at the part website. I understand that now, thank you for your help. Dan

My thought was its the thermostat too. Maybe being stuck open slightly which then allows the coolant to run around the engine constantly. At city driving speeds the airflow is minimal so it allows engine to get up to temp. With more airflow at 70mph the radiator reduces the temp in the coolant allowing it to drop to 70 deg c. I think the thermostat still fully opens as I don't run hotter than 90c so may just need a clean or a couple coolant flushes to take away any possible gunk that's keeping it open. Though ive heard that there are 2 thermostats on these cars but I'm not sure I've got them.

Okay. Do you think it would be simple as to chuck a new one in to fix it?

Hi all, I've noticed a small issue with my 2l tdi where in city driving my engine will warm up to 90 deg c and usually stay there but once im on a motorway it will drop to 70 deg c and hover around there. Engine runs like normal with no issues, new water pump + cambelt kit 4000 miles ago. Not had a chance to change the oil yet. I've got my own theories but thought I would pop the question out there and see if anyone has a clue as to whats going on. Cheers Dan

Cheers. Glad to hear I'm not the only one😆

Hi all, I've recently purchased a 2010 a6 Avant lemans 2l TDI 170hp so I thought I would join the owners club. Its the first car I've owned but I'm a mechanic on the side so I do most of my own maintenance. Already done 3000 miles in 2 months with plenty more on the way plus a European road trip later this summer. 45mpg average as i do mostly motorway runs + manual gearbox. Parts aren't too bad so far but the size takes getting used to with only rear sensors that are intermittent at best! Have a good one, Dan