Oil Level Sensor for VW Polo 9N

Hello, I have a Polo 9N 1.2L gasoline engine (AZQ) where the oil pressure warning light occasionally illuminates in red. I've already replaced the oil pressure sensor, but there's no improvement.

I have read the values from the Kobi instrument, and I couldn't find any errors.

mwb 001,3, Oil pressure switch, (0.9 bar)
003,2,Oil level, Value range: OK.
003,3, Oil temperature: 90 degrees.

Even if the lamp is lit, the values in the main window buffer (MWB) remain unchanged.

Does anyone have any ideas?

best regards, chris

Hello, I would only rely on the measured oil pressure.
Was changed? Is the correct switch installed?

Yes, I changed the oil and filter today.

Okay, I've also disconnected the cable from the oil pressure sensor, but it's still blinking. Usually, it should receive a ground connection through the switch, or am I mistaken?

best regards, chris

teileklaus wrote:

Hello, I would only rely on the measured oil pressure. Was changed? Is the correct switch installed?

I just measured the pressure using the pressure gauge.

Idle speed: 0.8 bar.

approximately 1.3 bar at 2000 RPM.

Hello!

I've now replaced the oil pump, but I'm still not getting any more pressure than I was with the old one.

According to VAG regulations, the pressure should be at least 2 bar even at 2000 RPM.

Does anyone have any other ideas? I'm completely stumped.

best regards, chris

I'm not familiar with the engine, but two things come to mind:
The oil pressure is dropping somewhere (could be a faulty bearing? Is the oil pressure relief valve open/defective? Could it be related to the oil filter?).
Oil pressure is not being generated (assuming the pump is capable of producing enough pressure).

I've already done a compression test and a leak-down test, and everything was fine.


Is the oil pressure relief valve integrated into the oil pump?

Hi, Oil pressure switch, 1.2 liters, suitable for all MKB engines. Switch pressure: 0.45 bar / color: green. Switching pressure: 0.3-0.7 bar. Test speed: 2000 rpm. Test pressure: 2.0 bar.
I'm saying that the 2.0 bar pressure on the oil circuit, specifically at the upper left side of the cylinder head near the oil pressure switch, is no longer being reached, even when using thin oil (0W or 5W).
Approximately 80,000 km is not really a lot for an engine to have been driven, suggesting it's not necessarily worn out.
Ich würde 10w fahren. Evtl. Longlife Öl? Rget rid of the dirt.
You can find the oil pressure relief valve in the old oil pump that has been removed. I'm not exactly sure where it is located in the three-cylinder, four-valve engine. It might be in the control housing or the oil filter housing. However, I think it's inside the pump itself.
Checked the oil filter screen for oil sludge? I think that might be attached to the new oil pump. What does the oil filler cap look like? Are there any hard deposits on it?

I also know that the lower part of the engine, including the crankshaft, should not be disassembled because the bearing halves will no longer fit together properly. This is a job for professional engine rebuilders.

Hi!
The engine is already filled with 10W40 oil, and I've located the oil pressure relief valve in the oil pump.

I almost think the problem is coming from the bearings. Although you don't hear any clattering, the previous owner probably drove it with an oil level that was too low.

I also noticed on the old oil pump that it had been replaced before, with the date "2008" stamped on it. I suspect that a different engine needs to be used because with this engine, nothing should be disassembled.

Hi,

Quote:

man hört zwar nichts klappern

, ist aber meistens so wenn der Öldruck nicht passt und der Motor mechanisch schon beschädigt ist. AlIs that okay?
I would suspect a faulty sensor, lines, or combination instrument if there are no unusual noises. You can check the oil pressure, even while driving, using a rubber hose and a gauge up to about 10 bar, if you want to be sure.