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.
1988 Plymouth Colt BaseFACTORY OEM SERVICE PROCEDURE
EGR System: Testing: THERMOVALVE: Carbureted
- Disconnect White-striped vacuum hose from thermovalve. Connect vacuum pump to nipple "A". See Figure . With engine coolant temperature at 50°F (10°C) or less, vacuum should leak when applied. With engine coolant temperature at 77°F (25°C) or more, vacuum should hold.
- Disconnect all vacuum hoses from thermovalve. Connect vacuum pump to nipples "B", "C" and "D" one at a time. Plug nipples other than one being tested.
- With engine coolant temperature at 104°F (40°C) or less, vacuum should leak when applied. With engine coolant temperature at 176°F (80°C) or more, vacuum should hold.
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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