Ticking noise from engine. Removed valve cover and oil was black,burnt and hard. on 1995 Nissan Pickup (D21)

Oil change was done 6 months ago, but driven maybe 800 miles in that time. Truck has low mileage (43,400). I'm getting air blowing out of oil fill cap when removed. Could a stuck valve have caused the burnt oil and air blowing out of oil fill cap? I changed the oil myself this time and the filter looked like it has not been changed for a long time. Very little oil came out of filter and it was very heavy. Not very easy to change/remove filter.

by in Venice, FL on October 29, 2011
1 answer 1 comment
ANSWER by on October 29, 2011
sounds like the system is sludged up. you need to service it more often. no telling how much debris is on the bottom of the pan. the blow by is from the piston rings which may be gumed up too from the oil. you need the engine oil system flushed out by a shop or it may not last too long the way it is. the ticking noise is most likely a sticking valve lifter. Roy
COMMENT by on October 29, 2011
Roy, thanks for your fast response. The truck is serviced at least once per year or 3000, but it is driven only local. Lucky if it gets driven 1000 mile a year anymore. The oil filter looked like it was not changed the last couple of times. Think I need to do my own oil changes for now on! I did have a shop flush the oil system about 3000 miles ago(2 years ago). Anyhow, when I removed the valve cover there was no sludge ... just burnt hard shiny crust. The truck starts great ... no smoke ... no miss. I do plan to drop the oil pan. Think I will have to rebuild the top end. Just don't understand how the top end got that hot and the truck has never over heated.