DB9 Top Gear Track
AO Silver Member
Join Date: Jan 2007
Location: United Kingdom
County: East Sussex
No need to disconnect the battery and I've changed them without warming the engine but it wouldn't hurt to do so if you're concerned.
9mm deep socket is needed. Don't change all of them, you're wasting money. If you have a multimeter remove the connector from each glow plug and measure the resistance to earth, should be a couple of ohns. Faulty plugs tend to be very high or open circuit.
If you don't have a meter remove the plug and reconnect the connector, earth the body of the plug and turn on the ignition (don't start the engine), check the plug heats up, replace any that don't.
Health and safety warning, they get very hot.
Loose - not close, compact, or tight in structure or arrangement
Lose - to part with or come to be without, as through theft, accident, negligence, etc.