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gomi_otaku, Technician
Category: Audi
Satisfied Customers: 3462
Experience:  VW certified technician, Chicago VW/Audi Training Center, Seattle VW/Audi Academy
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Oil pressure light comes on at low rpms, yes I only use the

Customer Question

oil pressure light comes on at low rpms
JA: Have you checked the oil? How old is your oil pump?
Customer: yes I only use the royal purple the dealer sells and I have had a new pump put in
JA: What is the model/year of your Audi?
Customer: 2002 audi A4 3.0 quattro
JA: Are you fixing your A4 yourself? What have you tried so far?
Customer: it works fine after an oil change but between 1000 & 1500 miles the light starts to go off again. The oil should be good after 1500 mikes miles
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 1 year ago.
Category: Audi
Expert:  gomi_otaku replied 1 year ago.

Is your level low when the light comes on? Because I don't think I ever see a light come on unless it is either empty, the oil pickup tube (and the oil pan) is sludged up, or the pressure switch is faulty

Customer: replied 1 year ago.
No my oil is full I have checked it several times
Customer: replied 1 year ago.
The only thing I can think of is its the actual low pressure switch. If I rev the engine above 2000 rpms it goes away. it only happens when im driving after going over 55mph then slow down to city speeds.
Expert:  gomi_otaku replied 1 year ago.

What viscosity of oil are you using? And what rpm does it idle at? The light is usually not active below 1400 rpm.

Customer: replied 1 year ago.
Not sure my mechanic does it he actually had to use a higher viscosity them the manual said. The was what the dealer recommended. it idles around 1200rpm
Expert:  gomi_otaku replied 1 year ago.

I would suggest removing the pressure switch at the filter housing and connecting an oil pressure gauge, see what it reads at cold idle, cold at 2000 rpm, and then let it warm up to operating temp and check it again. Either your oil is too thin (though you say it is fine for a few thousand miles) or maybe your injectors are leaking down overnight or overfueling while running, thinning the oil. Your idle seems a little high, it should be 800 or so. Do you have a check engine light on, or any faults stored?

Customer: replied 1 year ago.
No no other warning lights are on I will have my mechanic do that. Is it OK to drive while this is happening? or will it ruin my engine?
Expert:  gomi_otaku replied 1 year ago.

Judging by your comments, I think the sensor is reading OK- so it is a pressure issue, which can cause problems if you drive.

Expert:  gomi_otaku replied 1 year ago.

I think since it happens after you drive 55 or above, then slow down, that you have some kind of sludging in the oil pan- the particles collect on driving for a while, and sit there until you shut it off. Then they drop off and scatter until the next time.

Customer: replied 1 year ago.
ok thank you for your help