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My grandfarthers 2002 1.2 12v has developed a problem. It cut out with him on a roundabout the other day and started right away and has been running no problem since. But it put the engine light on.

And it has come up with 2 codes. (17925 - Main Relay Circ. Electrical Malfunction) and (16502 - Engine Coolant Temp.Circ High Input) I deleted them and it turned the light out.
A couple of days later its still starting and running perfect it has come up with the 16502 code again . but no engine light. Also when it is running if you take the oil filler cap off it splutters until you put it back on then cuts out, every time. Are they supposed to do that??

Many Thanks.

I dont think its designed to run without a oil cap

Have you checked the coolent level then? Any air stuck in the system?

When was it last changed?

is it in warranty?

Thanks for your reply.

Coolant is fine it was changed about 2 years ago but it has not done 3k since that, its still in good nick clean and strong.

The reason it splutters with the oil cap is the engine creates a vacuum with the oil - thats how it gets up to pressure

Taking the oil cap off should not cause it to stop running, nor should removing the coolant cap - however - both are pressurised systems and the caps should stay in place. (always be careful when removing either when the engine is hot)

The relay fault could just be a loose relay - start with basics and just press each one firmly back into the sockets. The coolant input could be a loose connection too, check the sensor connections and for any chaffed/snagged wires. Would be worth flushing the system through and re-filling.