Just did a full tune up on my 03 monte carlo ss. Know the low oil light is on.
Dip stick says full oil. Could these just be the oil level sensor sensor? If so were is it located at on the 3800?

 

in the oil pan

 

Hello, I found this on a message board, might give you somewhere to start looking. Interestingly lt says something about a faulty oil filter and you just changed yours, So??? I know a faulty filter is almost an unheard of event, but perhaps?

The oil light is not a light that tells you the oil level is low. It tells you that the oil pressure is low. Either the oil pressure sending unit is bad or you possibly do have low oil pressure. If you do indeed have low oil pressure then the oil pump my be bad or one other possibility is a defective oil filter. Replace the filter with the proper AC/Delco filter and see if the condition still exists. If so then have the oil pressure checked to see if you have good pressure. If you have good pressure then replace the oil pressure sending unit. Do not drive the car until you get the condition repaired.

Although the oil pressure light doesn't indicate oil level, GM vehicles do have an oil level sensor located in the oil pan that will indicate if the oil level is low. It is common for this sensor to fail causing the LOW OIL LEVEL indicator light to go on. This light is YELLOW indicating service is needed, however the OIL PRESSURE light is RED and this would indicate an EMERGENCY, seek immediate service before the oil pressure fails completely causing engine failure.