How about giving us the basics, like what engine do you have ?

If its a 22R/E it could be a loose timing chain has worn through the timing chain cover. You wouldn't se it in the exhaust (white smoke).

Or a blown head gasket (you might see it in the exhaust).

- seen in FOUR WHEELER mag July 2006 & OFF-ROAD mag Feb 2007 -
'84 4Runner ARBed 5.29s F&R,4.7 & 2.28 t-cases,hy-steer,BudBuilt skid,30spl Longs,36" TSLs,Chevys

'83 P/U, Buick 231 V6,Holley 4 bbl,Weiand intake,Downey headers,TH350 w/700R4 gearset