hey guys i was seeing if anyone can help me out. I just purchased a 1990 f150 with roughly 150000 mi on it. Before i purchased it the engine ran great. But recently it has not been running so good. I replaced the spark plugs, oil filter, and put new oil (10w 30). It also has a sort of knock that almost sounds like a slight misfire as well. A friend of mine told me to use a higher octane of fuel so i did. Now today when i was driving to work it started smoking like crazy. I checked under the hood and there was oil all over the right side of the block and hose on that side. When i looked to see where it was coming squirting from there was no sign of anything (even if i revved the motor). The only thing was there was smoke pouring out of the dipstick onto my hood which may have cause the burned oil vapors to liquefy and spill on the engine but that is just my initial thought. Please if anyone has any answers to any of these problems it would be greatly appreciated.
THANKS

 

The slight knock you were hearing could have been detonation (or something else) which can burn a hole in a piston. With smoke pouring out of the dipstick I would either perform a compression test on the engine or have one performed on it just to determine if thats what happened. Your friend may have suspected detonation when he told you to try burning premium fuel. Is the PCV valve still in place? Any codes?

 

I had a 76 Firebird that did that. It was a failed PVC valve.

 

Hopefully when you changed your oil filter you made sure the old gasket was still on the old oil filter and not stuck to the engine yet....