Glitch in The Matrix manifesting as a Local Gravitational Anomaly.

Not sure the car is new enough to be quite that broken though.

Polythene bag in your sump?

Using sunflower oil instead of motor oil could also cause this, but it would take time for the oil to gel.

Since you say youve probed the drain port, I suppose the next (logical?) move (apart from the pump out already suggested) would be to attempt blowdown by pressurising via the filler port, but you would need access to compressed air.

I would also lodge a technical query with Citroen, directly or via a main dealer.

This is one case where I would actually take my car to a dealer, which I didn't think I would ever say. I'd want to have some means of video recording though, possibly clandestinely.

Seriously, IF this is genuine, and you find out what it was, let us know.

Watch The Skies

Edited by edlithgow on 19/06/2024 at 01:40

.....overfilled slightly........ ..... oil and filter usually changed twice a year.

Why? Bit OTT these days.

Opened the sump plug to drain the excess oil and nothing....

Makes no sense....unless the car was upside down, or the new oil had immediately drained out of the plugless sump.

... but the engine is making that noise due to the overfilling

What noise is that? 'Overfilling slightly' is unlikely to change the engine sound; most manufacturers allow some leeway for error.

Possibly an episode of mental confusion resulted in the sump plug being replaced after rather than before refilling with a 5 litre can of oil, forgetting the intention to retain approx half a litre, so the new oil immediately drained into presumably a large receptacle or a hole in the ground, thus creating the illusion of overfilling plus the reality of an empty sump. Thus running the engine with no oil for 5 minutes might explain 'that noise'; but doesn't explain the lack of an oil warning light, unless it was faulty and failed to warn. The dipstick would show a coating of clean oil if not wiped.

Edited by John F on 20/06/2024 at 09:31