Volkswagen Golf Quiz
Carburetor Engine Fuel System

Thermostat Inspection

In this manual: Carburetor Engine Fuel System
General Information — 9Engine — 14Engine Disassembly and Assembly, 1.1 and 1.3 l Engines — 15Engine Disassembly and Assembly, 1.6 and 1.8 L Engines — 13Diesel Engine Disassembly and Assembly — 16Fuel System — 1Carburetor Engine Fuel System — 19Fuel injection system — 17Diesel Engine Fuel System — 15Clutch — 12Transmission — 37Transmission — 8Front-wheel drive — 5Steering — 12Front Suspension — 9Rear Suspension — 4Brake System — 16Body — 26Electrical System — 42Wiring Diagrams — 24
~1min read

PROCEDURE

Depending on the ambient air temperature or vacuum, the thermostat controls the flow of warm or cold air supplied to the carburetor.

A faulty thermostat will cause hesitation when the speed of a cold engine increases, higher fuel consumption and icing of the intake manifold. Check the thermostat on a cold engine. The thermostat flap must turn freely without sticking. Ambient air temperature must not exceed 20 °C. PROCEDURE 1. Disconnect hose 4 (see figure Air Cleaner for Engines with a Displacement of 1.1 and 1.3 L) from thermostat connection 6. Check the position of the thermostat flap; the warm air supply opening must be closed. 2. Remove the filter from the carburetor (see subsection 3.1.2).

3. Connect vacuum hose 9 to the carburetor, installing it on the nipple in place of hose 24. 4. Start the engine and let it idle. The thermostat valve flap should rotate and open the flow of warm air. 5. Disconnect hose 9 from the carburetor. The thermostat valve flap should rotate and close the flow of warm air within 20 seconds at most. If this does not happen, the thermostat valve must be replaced. Check the thermostat valve on engines with 1.6 and 1.8 L displacement in the same way.

Test yourself

A quick Volkswagen Golf quiz: every answer comes with an explanation and a link to the manual page.