no oil on top

[Tnscooter63]

Hello, I have a 93 gmc sierra king cab with 350 motor and auto, I have been noticing it clattering some here and there, but untill now it would stop after a few minutes, I put a hose to the ear to find the source and is deffinately from the rocker arms, and looked bone dry in there. Would this be the lifters? and would all go out at once? any and all help would be appreciated, Thanks, Scott

ps: I did check, and there was enough oil in the pan, and oil pressure is normal.

[maxwedge]

Possible the pushrods are sludged up or possible all the internals. What does the inside of the engine look like?

[Tnscooter63]

Hello, and thanks for the responce. The inside is a bit a bit sludged, looking in from the filler cap, has just over 209K miles. I have never heard anything good about the engine flush products, dont really want to use them, guess I will take it apart tomorrow and clean and inspect, can the lifters be cleaned or would in most likely be where the pushrods connect, has been a long time since I messed with internal parts, anything to specifically look for on lifters for not working properly? Thanks, Scott

[maxwedge]

If this engine is sludged up inside the valve covers, the lifters and pushrods could be restricted, but more importantly so could the oil pump pick up screen.

[Tnscooter63]

Good morning and thanks for the replys max, I changed the oil this morning with a lighter wieght oil ( valvoline 10w-30 ) I have been a die hard castrol user, and it has stopped the clattering, I drove it a bit and got it to normal driving temp., then let it cool off and started it again, and still not clattering. On a scale of 1 to 10, I would consider the sludge to be about a 4 inside the valve covers. It has been a year or 2 since I changed oil, and only about 1500 miles, sice I havent used the truck much until lately, mostly pulling the boat fishin, Could the oil weeken over this time, or would you think I will still need to drop the pan and pull intake to clean as much as possible? I really didnt think I would need to rebuild it for another 100k miles or so, from what I have deen of others, but when I do use it I work it hard. Thanks, Scott

[maxwedge]

For safety's sake maybe drop the pan and look at the screen, if good perfect time to replace the oil pump just for ease once the pan is off, if it is sludged around the screen or the area under it post back.