PAINTED A ROOM 3 MONTHS AGO AND STILL SMELL SO BAD YOU CAN’T STAND TO GO IN. THE SMELL IS NOT LIKE PAINT VAPORS, IT’S A RANCID SMELL. The room was painted several months before repainting it and did not have a problem. Applied a primer before repainting. IT is not a dead animal smell. I have read on internet that this is not uncommon and painting over with a prime does not seem to help. Do you know of any solutions?
There's no easy solutions to this problem. The main thing to consider is the quality of the primer and/or paint used as this seems to be a common link to the reports.
Using a shellack based primer (2 coats) could help to seal up the smell if it caused by the primer or paint alone. After the primer using a high quality zero VOC paint should take care of the problem.
I agree with Dave that a pro should be contacted. Plus contact the primer and paint manufactures and let then know about your smell problem, maybe they will have some specific remedies.
This is a common problem with people that save paint for a long time. Paint does become ransid due to the chemicals in it especially when its stored in hot places like garages with no insulation.
Usually this smell only lasts for a week or so. If it does not go away then you may have to repaint with fresh paint.