So recently my engine started to burn some oil. Its a 4.6 in a 1998 F150 Lariat. It doesn`t burn any at all until it warms up. Its most noticeable when stepping on the gas pedal after sitting at a light for a bit, and it doesn`t seem to burn any just driving along. I was thinking it was the valve seals, but kinda thought that I would get a huge puff on a cold start as the oil would be able to make it past them(valve seals). I'm using 5W30 oil. It also seems to get worse the warmer the engine is. Do these engines have any issues that would cause excessive oil burn like this? Any thoughts would be appreciated.
Thanks

 

My first guess would be rings since you say it occurs on acceleration after sitting. There is some information missing, like how many miles on engine, service history (oil changes on time, etc) and how much smoke and what color?

 

Thanks for the reply. I've oly had the truck for 3 months now and it has about 234000 kms. not sure what that is in miles. when I bought it the oil was clean and the engine had no external leaks and still doesn't. The smoke is definately blue. I just kinda thought if it was rings it wouldn't wait till the engine had totally warmed up. Are these engines known for ring failures or headgasket issues?
Thanks

 

They're not known to burn oil due to any of those issues. It is possible that they, as any engine, can. You need to do a wet/dry compression test to verify where you're burning the oil from.