Knocking noise in my YJ -
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post #1 of 3 Old 02-23-2012, 12:07 AM Thread Starter
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1988 YJ Wrangler 
Join Date: Oct 2010
Location: Brookfield
Posts: 16
Knocking noise in my YJ

I have a engine knock in my jeep
Its got a 4.2 I6 and iv'e only put about 15000 miles on the motor.
I believe I have a gunked up lifter. The jeep was running rich and I have a weber carb and made some adjustments to increase my mileage and make it not so eye burning. Since then I have noticed the knocking noise. I am going to change the oil with some 10w40 or better and see if that helps or stops it.
What would be another step to take to help stop this problem?
I'm hoping I don't have a bad rod and can change oil or take lifters out and clean them up.
Any help from someone has had this kind of problems would be great.
I really don't wanna hafta rebuild or buy a new motor again for my rig.

WillieD is offline  
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post #2 of 3 Old 02-23-2012, 02:17 AM
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1987 YJ Wrangler 
Join Date: Jul 2011
Location: Louisville
Posts: 196
If it is a new motor, i would suggest taking it to a certified shop and having them check it out before something really goes wrong with it. If you think a thicker oil is going to fix it do your self a huge favor and take it into a shop. That will not have any long term fix even if it does anything at all.
codymiguel is offline  
post #3 of 3 Old 02-23-2012, 07:13 AM
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1987 YJ Wrangler 
Join Date: Feb 2008
Location: Raleigh, NC
Posts: 426
Lifters tap or tick, rods/pistons knock or can narrow it down by watching what rpm & conditions that occur when you hear the noise. Rod knocks tend to occur (be loudest) in each gear, at low RPM w/ a heavy load on (getting on the gas). Lifters are constant & not really dependant on load.

For instance, I have a noise that sounds exactly like a rod knock.....but it only occurs in 1st gear under light load. Won't happen in any other gear, or neutral, or coasting or heavy load. I'm 95% sure that it's the POS BA-10 tranny on it's way out.

You can check for a rod knock by putting the tranny in drive, stomping on the brake & also trying to accelerate (moderately, for a second or so)....if you have a rod/main bearing going out, it'll make the noise then.

probably out breaking stuff.

Last edited by Beachcruiser; 02-23-2012 at 07:15 AM. Reason: Checked profile for transmission type
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