Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1978 BMW 633CSi Automatic TransFACTORY OEM SERVICE PROCEDURE
THERMO Valve: 320i
- Disconnect thermo valve vacuum hose at EGR valve. Disconnect the other vacuum hose from thermo valve. Blow air into hose connected to thermo valve.
- Thermo valve should be closed with coolant temperature below 91°F (33°C) and fully open with temperature above 109°F (43°C). If not, thermo valve is defective.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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