why would a person change oil for this car from 10/30 sae to 15/40 diesel oil ?
We are working on a 96 Deville. The guy putting the a/c compressor didn’t tell us he had to take the oil filter off to get the compressor on it. We came in the next morning and started it to back it out. I seen the oil puddle and shut it off. Now it turns over’ but we can’t get it to start. We changed the key and tumbler we got from the dealer and the security light is not flashing.