93 Pontiac Grand Prix engine noise?

Question

My engine makes a light knocking noise that is coming from the top of the engine. its a steady knock that changes with engine RPM. The knock sounds like it is two knocks happening very fast. it is coming from the top rear of the engine. The oil pressure is still good. it has 65psi at full throttle and 35 at idle. its a 3.1L V6 with 158,000 miles.

how long can the engine run like that. Its not a loud noise and their is nothing in the oil

Answer 1

i own a repair shop and it sounds like you have a valve lifter not working right on it or a bent push rod on it,i have owned several 3.1 engines and they are one of the best ones that gm built,but i have seen a few of them with bent push rods,another possibility on it also is bad lobes on the cam shaft ,this happens a lot to gm products,they use to soft of a metal in making them, but you can pull the valve cover off and check it or have it checked,it may just need adjusting,at least you,ll know when you have the valve cover off of it,good luck with it hope this helps.

Answer 2

well if its the 3.1 V-6 then its prob the intake manifold gasket leak. its leaking coolant in to your oil and creating sludge in your engine. a common known thing. so best way is to open your oil cap and look in the hole to see if you see sludge. or pull the valve cover to get a good look. but thats what it sounds like. pull your dip stick out and smell the oil on the stick. if it smells like engine coolaint. then thats what it is a coolaint leak.

do a google search for your engine and include sludge and you will see a ton of complaints.

Answer 3

i hate answer a question with a question, but it does aply. have you had the valves adjusted? this would or could produce a light tapping sound, that would change frequency and intensity based on rpm. you might want to look into it.

Answer 4

you may just be low on oil. check the level,and if its good then try switching to a heavier weight oil.