Car clinic: How do I fix a faulty oil-level warning light?

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Car clinic: oil

Q. The dashboard oil-level warning light in my 2002 Volkswagen Passat is permanently lit. Topping up the oil hasn’t helped, nor has fitting a new oil-level sensor, and a diagnostic check didn’t come up with anything. My local garage now thinks it’s the instrument cluster at fault, and says this will cost £500-£600 to fix. As the car only cost me £1,400, what else can you suggest?
RH, Oundle, Northamptonshire

A. It is possible to get your car’s instrument cluster repaired more cheaply than that. We spoke to the instrument repair specialist Cartronix (, which quoted a standard repair cost of £99 (plus £12.95 postage, if it’s needed).

However, the cluster is unlikely to be the source of the problem, especially as no fault codes are showing up.

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The culprit is far more likely to be degradation of the engine-bay wiring to the oil-level sensor. Although this might sound cheaper to resolve, it may in fact require some — or maybe all — of the wiring loom to be replaced.

Together with the cost of several hours of labour, this repair could add up to the £500 or so you’ve already been quoted.

If you don’t want to spend that kind of money, just ignore the light, as its function is not tested in the MoT. But you will need to be certain that the engine is not losing oil, by checking your dipstick at least once a week and looking out for any tell-tale oil drips on the driveway.

These are all things that drivers had to do anyway before the oil warning light became commonplace, and it’s a wise thing to do as, if the warning light does come on as the consequence of a genuine fault, the engine oil level is likely already to be dangerously low.

Sunday Times Driving car clinic expert: Dave Pollard

Dave Pollard has written several Haynes manuals and has tested just about every car-related accessory – read more from Dave here.

Email your question to or write to Car Clinic, Driving, The Sunday Times, 3 Thomas More Square, London E98 1ST, with a daytime phone number, your address and as much detail about your car as possible. We can’t reply in person, so don’t send original documents or SAEs. Advice is given without legal responsibility.