Oil pressure low

[AlejandroMaximus]

Hi, I have C4 first gen. with 1.4 engine. Recently it started to beep with "oil pressure too low", but it has few... specifics.

1. It only beeps after the engine has warmed up and usually only after the heated engine is turned off for a while and then started again.

2. it only beeps while idle. As soon as the rpm is even slightly over 900, the red "STOP" label turns off.

3. I changed the pressure sensor as I thought it might be the first thing to go wrong and it was cheap and easy to fix, but the problem still persists.

Could it be oil filter? I doubt it. Could it be the worn out valve for when the oil is cold? ( to prevent too high pressurre, dont know what it is called). Last thing I would like to replace is the oil pump....

vidmate mobdro word counter
Thanks for any insight.

Bearbeitet 28. März 2020 von AlejandroMaximus

[schwinge]

Hi,

judging by the symptoms, this is not a sensor related issue. Oil becomes less viscous when warmed up, hence the oil pressure drops. The oil pressure is lowest in idle, thats why you get the lowest oil pressure when idling with hot oil.
The oil filter has a valve built in. If the oil flow through the filter material is restricted, it will open to avoid damage to the oil filter material. So, the oil filter is not your issue either.

You might have an issue with either the pump not producing enough flow rate (pickup screen clogged or leak on oil pickup, worn pump) and/or too much oil loss after pump (stuck oil pressure regulator valve, worn bearings).

Kind regards,
Michael

[bx-basis]

Check/replace the oil filter, sometimes they break apart and cause the symptoms you described.

[ACCM Helmut Bachmayer]

In contrast to Michael, I am at bx-basis.  The oil filter has a small cross in the middle that breaks off now and then.  This cross presses on the bypass valve.  If this is broken, the technology stops working.  In rare cases, the mechanism in the oil filter housing is broken.  There is a spare part for this, which is a little tricky to replace.  Many people do not know this possibility and also not the existence of the spare part. But mostly it is enough to replace the oil and the filter. Check the filter after removal for the cross.  But before you mount the new filter, make sure that you can see a black part that you can press down by hand. This is the part pushed down by the cross in the filter. If it is missing, you will have to either change the housing of the filter or search for a good motivated mechanik to get the above mentioned spare changed. Tricky but possible. Good luck der Bachmayer 

[schwinge]

Ah well, the blessings of new technology. It seems, I need some education in that regard. Thanks, Hendrik and Helmut for correcting me. Of course, if you have an oil filter where only the filter element is replacable, the valve must be in the housing.

[Robbo]

Hi.i have a 1.2 petrol cactus 16 plate...oil pressure low keeps coming up.had new filter and oil pump cleaned 2000 miles ago when this happened before.now it's started again.only got 35 thousand on it

[Gernot]

Might be a sensor (oil pressure contact) problem. Any workshop may check oil pressure.

Check timing belt for wear immediately! It is running in the oil chamber and wear may be clogging the oil pump. It is a common and well known problem of Puretech 1.2 engine.

Gernot

Bearbeitet 4. Dezember 2021 von Gernot

[ACCM Helmut Bachmayer]

The lack of oil pressure is caused by the worn out timing belt material. The sludge sits on the little sieve of the oil pump. So better remove the oil pan and clean it. Stop using the vehicle until the belt is really fixed. Sorry for the bad news and good luck, der Bachmayer