I hope someone can help.I've been having some problems (burning plastic smell, remote starter/lock not working right) with my 1998 Sonata GLS (6 cylinder) and when I was looking at it today, I took off the air filter hose and there was oil in it. Does anyone know what would cause this? Should I bring it to the dealer? Thanks in advance for any help you can offer.

 

It's oil vapor from the crankcase being pushed into the intake from blowby pressure. How old is the PCV valve? It probably needs to be replaced..

 

Not sure how old PCV valve is, I've had the car 6 years and haven't replaced it. I will try that and see if it solves the problem. Thanks for your help.

 

Just wondering if you got your problem fixed? I have a 2003 elantra with the same problem. I have replaced the pcv valve and that didn't help.

 

Try some Auto-RX. http://www.auto-rx.com/ It will slowly clean the carbon from behind the rings and reduce the blowby.