Fit a modified AUDI TT oil pump to the car, replaced the oil pressure sensor, but oil pressure light still on! 2005 Volkswagon

ANSWER : Hello – I would first put a real oil pressure gauge on the port for the oil pressure switch and see what real pressure looks like before driving it. Low oil pressure light switches trigger at only about 5 psi, so if the switch/gauge are working correctly, you’ve got real problems (worn connecting rod and crankshaft main bearings most likely) with this engine. I recommend a low oil pressure inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

ANSWER : The fuel pump will not stay on if you loose oil pressure. This is why it is shutting off. The loss of oil pressure may be from bad crankshaft bearings or camshaft bearings. The engine oil pan should be removed and the oil pump needs to be checked to ensure that you put in the pick up tube seal to the pump and connected the pump to the block. Then remove at least one main bearing cap and inspect the bearings for excessive wear and crankshaft damage. If you need some help with this, consider YourMechanic, as a certified technician can help diagnose the issue with your oil pressure firsthand and help you fix it accordingly.

ANSWER : Hello. If you put too thick of an oil in the car, then you may have damaged the engine bearings but this should not have caused oil to get in to the spark plugs unless the oil got into the intake of the engine or one of the pistons rings broke. If you ran it without oil and then tried to put oil in thinking it would be okay after that, then you were not that lucky and broke or damaged all of the rings on the pistons. If you would like to have this looked over, a certified professional from YourMechanic can come to your car’s location to inspect the stalling issue and go over all of the relevant systems for a better diagnosis.

ANSWER : Hello, thank you for writing in. Particularly having the check engine light on, the vehicle will have set off diagnostic troubleshooting codes that pertain to whatever component has set off the warning lights. You will want to start by having these codes read by a scan tool, which can be done by a technician, or at most automotive parts stores. Once you have those codes, you may have a better idea on what is going wrong. Without the diagnostic codes, and considering what you have already done to the vehicle, you will want to look into the condition of the oil pump and oil pressure sending unit. Keep in mind that the oil pressure is supposed to raise and fall with the RPMs of the engine. The lower the RPM, the less oil pressure generated or needed by the engine (generally speaking 10 psi/1000 RPM). Start with scanning the vehicle for diagnostic codes to determine what the engine has already detected is wrong, and take further testing from there. For more help, contact our service department to schedule an appointment.

ANSWER : If you have replaced the sensor three times and it did not fix the problem, then you may have problems with the oil pressure being low at idle due to wear in the engine bearings. The reason it would be fine sometimes and not others may be due to engine load and temperature changes. Have the oil pressure tested at the sensor port to see if it is low and needs engine repairs.

I recommend having a certified mechanic, such as one from YourMechanic, come to your location to perform an inspection to determine why the Oil Pressure Light is on.

ANSWER : Bob: Thanks for your inquiry. Oil level and oil pressure are measured using separate sensing systems. If the level sensing feature stopped working at the time the pan gasket was replaced, either the level sensor was damaged, not reconnected, or the wire harness and terminal were damaged. There is a possibility that the wire harness was just never re-connected to the level sensor so check that first. If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a warning light diagnostic – oil level and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : It is possible that they put in the wrong viscosity oil. In rare instances, a defective filter will also cause low pressure. If there is too much oil, it will aerate and cause low pressure. Be sure the oil level is really not above "max". The P2187 code will appear if the oil fill cap is not tight but it will also appear due to a myriad of causes because that code only "generally" identifies a lean running condition. Consequently, numerous parts would have to be tested including the O2 sensor, gas cap seal, manifold air leaks, any vacuum leak anywhere including PCV and EVAP systems, exhaust leaks, and fuel system faults such as failing fuel pump, clogged filter and more. Since the car has relatively low mileage, you would not expect a failed oil pump, although the pressure sensor (or switch) could be bad. However, the occurrence of the oil pressure warning light is quite coincidental to the oil change, thus I would suggest bringing the car back and asking them to redo with a new filter and double check the viscosity of the new oil that they use. If the problem persists after that, you will have to test actual operating oil pressure (at idle for instance) as well as the oil pressure switch. Finally, if the oil pressure warning light comes on continuously, unless the warning circuit itself is malfunctioning, that means the oil pressure is too low to operate the engine without damaging it. Anytime the light comes on for more than literally an instant, you should shut down the car and thus an issue like this obviously has to be repaired.

If you’d like, a YourMechanic certified mechanic can come to your home or place of business to inspect the vehicle and perform an oil pressure light is on inspection to diagnose the vehicle and suggest potential repairs.

ANSWER : The oil pressure sensor only "reads" and reports pressure. The sensor itself cannot "affect" or "set" pump pressure. If the oil pressure warning light illuminates AND there is coincident unusual engine noise, that almost undoubtedly means that oil pressure really is too low and you should turn off the engine immediately to prevent damage. If the engine oil level is too low, that can cause low pressure so be sure to check the level on the dipstick. If the oil level is OK, then the lubrication system will have to be diagnosed and that would, of course, include consideration of the possibility that your oil pump has failed. To get this resolved, please request an oil pressure diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.