Glossary “Dexron V” Definition:
Updated ATF
d
DFC
Glossary “DFC” Definition:
Deceleration Fuel Control
DFI
Glossary “DFI” Definition:
Digital Fuel Injection, or Direct Fuel Injection
DFS
Glossary “DFS” Definition:
Dual Function Switch, or Deceleration Fuel Shutoff
DI
Glossary “DI” Definition:
Distributor Ignition, or Direct Ignition, or Direct Injection
dia
Glossary “dia” Definition:
Acronym form of Diameter.
Dexron II
Glossary “Dexron II” Definition:
A petroleum-based automatic transmission fluid developed by GM.
Dexron III
Glossary “Dexron III” Definition:
Updated ATF
Dexron IV
Glossary “Dexron IV” Definition:
Updated ATF
Detroit locker
Glossary “Detroit locker” Definition:
A specific brand of locking rear-end differential.
Dex-Cool
Glossary “Dex-Cool” Definition:
Long-life antifreeze manufactured by Texaco. Used in most GM heavy and light duty vehicles, Dex-cool is an ethylene glycol based antifreeze that contains (OAT’s ((Organic Acid Technology)) rather than nitrates and phosphates or silicates as corrosion inhibiting chemicals). Normilly dyed Orange to distinguish it from other ethylene glycol antifreezes and polypropylene glycol.
Dexcool
Glossary “Dexcool” Definition:
See Dex-Cool
de-torque sequence
Glossary “de-torque sequence” Definition:
Shop Manual may supply a specific de-torque sequence for a component. For components that do not have a specifc de-torque sequence, reverse the tightening sequence.
detonation sensor
Glossary “detonation sensor” Definition:
A device, mounted on an engine block, cylinder head, or intake manifold, that generates and sends a small voltage signal to the PCM, to retard timing, when encountering the vibration frequency associated with detonation.
detonation-detection sensor
Glossary “detonation-detection sensor” Definition:
Term used for detonation sensor or knock sensor.
de-torque
Glossary “de-torque” Definition:
Method f0r removing a component that uses multiple fasteners in a specific order. The clamped surfaces are under tension and loosening the bolts relieves the tension. De-torque allows the surfaces to relax at an even rate and prevents the component distorting or cracking. This should be done after the component has cooled.
detergent oil
Glossary “detergent oil” Definition:
An oil with a detergent additive.
detonation
Glossary “detonation” Definition:
A phenomenon of internal combustion where the compressed air/fuel charge explodes violently instead of burning smoothly, usually due to the creation of a second flame front in the combustion chamber, away from the spark plug. Sometimes resulting in an audible knocking noise, which can be harmful to the engine.
detergent dispersant
Glossary “detergent dispersant” Definition:
Chemical component in motor oil that loosens dirt and varnish in an engine.
desmodromic valves
Glossary “desmodromic valves” Definition:
A valve system in which positive cam action, not spring action, is used to open and close the intake and exhaust valves.