997.1 C2S oil light

[yak293]

Just a quick question please.

when driving this car reasonably enthusiastically on occasions the red "oil can" light flashes when breaking hard on uneven roads.
oil level on computer appears within the high low range.

A minor glitch or a sign of more ominous this about to happen.???

cheers

y

[ForzaWhitesGen2]

You need to top it up mate.

Park the car up and let it cool down.
Put the key in and turn the ignition on, what does the Oil dipstick bars show?

I think (could be wrong from memory) that each bar is roughly 200ml... so top up the oil a little and retry?

[yak293]

its in the Middle to upper range at present.

[ForzaWhitesGen2]

Well there's enough oil in there then.....

Actually am sure it could come on if infact you have Over-filled?

Have you done a lamp test on the Oil warning light?

One thing I've heard a few OPC's do is completely drain the oil, refill
and the problem goes away.......

Edited by ForzaWhitesGen2 on Monday 20th February 12:54

[Rockster]

yak293 said:

its in the Middle to upper range at present.

Maybe.

Trouble is the reading may not be accurate/reliable.

When in doubt I like to make sure. To be sure the engine should be properly drained of oil and the correct amount of oil added to the engine then the oil level sensor/sender oil level reading should be taken and checked to ensure it is reporting the right amount of oil is in the engine.

Then you know if the oil light flashes or the reading varies the sensor/sender is bad, or perhaps a sensor/sender or dash wiring connection is loose or bad.

Sincerely,

Rockster.

[yak293]

this sounds like a good call.

thanks will action Asap.

cheers

[Ian_UK1]

yak293 said:

Just a quick question please.

when driving this car reasonably enthusiastically on occasions the red "oil can" light flashes when breaking hard on uneven roads.
oil level on computer appears within the high low range.

A minor glitch or a sign of more ominous this about to happen.???

cheers

y

I've encountered this issue in the past - albeit in a facelift 996. It may still apply though, as the oiling system is substantially the same.

As well as the main oil pump that supplies oil to various parts of the engine, there are also two oil scavenge pumps fitted - one in each cylinder head. The purpose of the scavenge pumps is to return oil to the sump when cornering, as g-forces would prevent it returning by itself. (Imagine you are going round a right-hand bend. Oil supplied to the left hand cylinder head will be kept in the head by centrifugal force unless pushed back towards the centre of the engine and ultimately the sump. Vice-versa for left-hand bends). The scavenge pumps are located on the end of one of camshafts in each head and driven, together with the camshaft, by the cam chains.

In my old 996, one of these scavenge pumps had failed. The result was that when cornering, oil was being pumped from the sump around the engine, but very little was being returned to the sump due to the lateral forces. As a result, the oil level in the sump dropped until the main oil pump could no longer pick-up any oil and the warning light was triggered. This may be what's happening in your engine.

Be in no doubt that if this is the problem, it could very easily destroy your engine in seconds. The oil warning light means no oil pressure - hence no oil feed to your engine. You shouldn't use the car until this problem has been properly diagnosed and appropriate repairs made. If it is a scavenge pump, the fix isn't horrendously expensive and the engine will work perfectly normally again one the part is replaced.

Edit: A failed scavenge pump can also cause the same symptoms if you drive the car very hard in a straight line. Oil can be supplied to the head with the faulty pump faster than gravity can return it to the sump with the result that the level in the sump continually drops until the warning light is activated. The symptoms will be a lot worse round either left or right hand turns though (depending on which pump isn't working).

Edited by Ian_UK1 on Wednesday 22 February 10:38