A4 Cabriolet L4-1.8L Turbo (AMB) (2005)
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Thermostat Housing: Customer Interest
Cooling System - Coolant Leak/No or Poor Heater Output
19 07 01
March 26, 2007
2009949/3 Supersedes Technical Service Bulletin Group 19 number 05-03 dated Apr. 8, 2005 due to revision of a part number.
Vehicle Information
Coolant Leak or No Heat in Passenger Compartment From HVAC
Condition
Coolant Leak or No Heat in Passenger Compartment From HVAC System
Technical Background
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Customer concern of loss of coolant, but no leak in cooling system can be found.
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Customer concern of no heat or noticeable drop in heat output in passenger compartment from HVAC system when engine at idle.
Both concerns may be caused by a coolant leak from plastic plug.
Plug is installed in engine cylinder block near connection for thermostat housing (arrow).
Improved Coolant Plug.
Service
Other than loss of coolant, a leaking plug can cause air to enter into the cooling system and reduce the effectiveness of the passenger compartment
