rod knocking?

[johnschmitt]

Hello. I've got a 99 malibu with the 3100 V6 and about 93000 miles on it. The lower intake gaskets are about a month old and I've noticed what sounds like a rod or a lifter knocking when the engine's cool. I've read that it could be piston slap, but it knocks about 3-4 times a second. I would think the knock would be a bit faster if it were pistons doing it.

A friend of mine whom I trust has the same motor in his 98 Grand Am and he suggested oil stabalizer (didn't quiet it down) and then suggested 10W40. He's been running castrol 10w40 since about 60,000 miles. It now has 125,000 on it and he says it's nice and quiet.

My question is, have any of you had luck doing that and will the heavier oil cause problems with things such as the oil pump and what- not?

Thanks a lot,

John

[peterdash69]

i have the same problem with my 2002 i tried thicker oil and did the same so i just use the 5w30 remind you that i have only 63,000 miles

[MyBluMalibu]

Just so you know, I am in the process of replacing my lifters now. My hubby had the idea of putting in 10W30 in on the last oil change to make the knocking quiet down. Well it did. Now had we known that it was the oil pump going out we could have saved us alot more money on out 98. We also have the 3.1 V6 and I would not recommend doing this as it causes more trouble and money not to mention the time!@@###! Now we are just hoping that I did not mess up the cam because 2 lifters out of the 6 are bad and the push rod in one of them is bent pretty good! Auto Zone cannot order the cam because it is a dealer part! But advise to you would be to replace the oil pump as soon as possible and run the 5W 30 in it.