rough idle
Senior Member
Joined: May 2012
Posts: 157
Likes: 5
The engines run fine on 5w30. Same exact engine in EU and AUS run 5w30. 5w20 was for CAFE requirements. If you are considering a new engine it won't hurt to try a heavier weight oil and see if it cures the rough idle.
Senior Member
Joined: Feb 2009
Posts: 714
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From: Cliffwood Beach, NJ
Originally Posted by GrnMachine210
Might not apply to all of yall engines. But i know on the 2004 and 2005s, a stuck PCV valve can cause rough idle and bad throttle response. Worth checking.
Member
Joined: Dec 2010
Posts: 76
Likes: 2
My truck is a 2004 If i understand the mechanic correctly the left bank is the last place to get oil when it circulates through the engine and with so much play in the crank it doesn't have enough oil pressure to keep the left cam in time that is why the whole left bank is misfiring. I was told that i could put new thrust bearings in the engine but several had already been done this way and it doesn't last long the motor starts running bad again after a short time and that the best thing to do is drop the new latest motor in.
It to another shop for another opinion..... And as far as oil Weight I wouldn't worry a bit about changing it I run 10w40 it's synthetic blend but I'm also in Texas it doesn't get cold here..... I would contribute rough idle to vac leak something dirty or plugged I would rule out COP due because of only running bad at idle.