A3 1.6tdi Cooling Problem

[alhal0151]

2009 Audi A3 1.6tdi Convertible. 80k miles.

At my absolute wits end with it now.

Oct 2016 car started to overheat. Diagnosed as EGR failure by Audi dealer. Replaced by independent Audi specialist.
Car returned to me, driving as normal but radiator fan constantly running.

Nov 2016 Flywheel failure.

Dec 2016 Car went into limp mode - DPF blocked. Apparently it had not re-generated due to previous faulty EGR. Unblocked by specialist.
When car returned heater not getting warm and car overheating when exceeding 40mph (message on dash saying switch off engine).

Cam belt / Water Pump / Thermastat / Auxillary Water Pump / Temperature sensors replaced by independent specialist.

Jan 2016 Car still overheating. Radiator removed and checked for blockages. Heater fans only getting luke warm. Radiator pipes not getting warm. Head gasket has been checked. No oil or pressure in coolant. Car drives fine with normal power acceleration etc until it overheats.

Audi specialist unable to offer any further suggestions.

MOT has now run out on the car and obviously I cant take it for one when its overheating and going into limp all the time.

I only bought the car a few years ago for £16000 and have thrown £3000 at it in the last 2 months. Seems that i'm now going to have to sell it as scrap / spares or repair unless anybody on here has any suggestions!? Please!

Thanks

[Rob69]

The most recent symptoms point towards an air locked system or slipping water pump impeller, if the thermostat was remaining closed I would still expect the heater vents to get hot, no heat to the heater means no circulation ( or blocked heater core but unlikely). I'm not familiar with this engine but have you looked for vent points through the cooling system? Did you get the water pump etc done in dec 2016 at the same time as the DPF job and since then it has been overheating?

[alhal0151]

Thanks for your reply, when the car came back from the DPF job it was still overheating but the heater vents had stopped blowing hot air (they were previously). So it went back to the same place for a new water pump and cam belt (they said there was actually nothing wrong with the old pump but may as well change it whilst it was stripped down).

The garage assures me that they have fully bled the system....

[Rob69]

Like I say I'm not familiar with that engine but symptoms point towards a thermostat or circulation problem, unlikely to be the water pump, since that is new. see cooling system diagram on these links, there is a 4/2 way valve fitted in some, or maybe all 1.6 engines, in the stat housing, I don't have any more detail on this valve but my money would be on a problem with the coolant circulation, maybe something to do with that valve as it looks like your heater return and oil cooler return lines go via that valve on the schematic.
hopefully someone with more experience of this engine will be along!

Coolant hose schematic diagram (vehicles with 4/2-way valve, Golf, Passat, Touran) (http://workshop-manuals.com/volkswagen/golf-mk6/power_unit/4-cylinder_diesel_engine_(1.6_l_engine_common_rail)/engine_cooling/cooling_system_coolant/coolant_hose_schematic_diagram/coolant_hose_schematic_diagram_(vehicles_with_4/2-way_valve_golf_passat_touran)/)

Removing and installing 4/2-way valve with thermostat (http://workshop-manuals.com/volkswagen/golf-mk6/power_unit/4-cylinder_diesel_engine_(1.6_l_engine_common_rail)/engine_cooling/coolant_pump_regulation_of_cooling_system/removing_and_installing_4/2-way_valve_with_thermostat/)

[DMcCo]

Did you ever get to the bottom of this?

[DMcCo]

Will send an email

[Jonner123]

I have a similar problem. Would like to know what it was too. Cheers