Happy new year folks,
Just want to run this theory past you - be very grateful for any ideas...
Re: my car in the subject line: The engine fault light went through a phase of coming on after a run of about 10 miles. It always cleared after turning the engine off and on again. It sometimes cleared by itself a few miles on. Hasn't done it at all during the last week. Can't afford Vauxhall to run a diagnostic, they tried to charge me 80 quid last time I went down that route.
So, I performed a paperclip-in-the-ALDL-port diagnostic and that indicates it *may* be the coolant temp sensor, registering an overheating condition.
The engine is patently not overheating and the dash temp gauge (fed off a different sensor) indicates all is normal.
Dicky sensor and/or wiring seems likely to me. It's a hard to get at sensor so I can't even wiggle the wires, but am considering speculative replacement during the next cambelt change. When the fault light is on, idling isn't good (some hunting) but the car runs acceptably. It may throw the emissions off so I should try to fix it before the next MOT (or running into a VOSA team, but that's pretty unlikely IME).
Does my theory and replacement plan sound reasonable?
Many thanks in advance,
Tim