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Engine noise knock

04-11-2013, 08:56 PM
Hi everyone , bran new to this forum and computors hate me.I parked my mothers 1995 buick lasabre last year with 100,000 miles just broken in as far as iam concered.Well I have vacation coming up 1 week 168 its time to fix it.Problem is at 50,000 miles engine sounded like a rod knock at idle race motor up noise disappears.At road speed in gear traveling no noise.Stop at a red light in gear or neutral sounds like a rod knock.Been this way for 50,000 miles.Dealer replaced power steering pump ,2 belt tension , ac compressor , alternator.Dealer pulled the oil pan said bearings are no good. Wanted 3,200 foe a gm rebuilt in stalled.Car got parked. All this time Iam thinking harmonic balancer.Is it possible the balancer. Car runs fine smooth 25 miles to the gallon yes It just knocks away .ANY HELP ANY IDEAS THANKS HOPE I FIND EVERYONE WELL AND HAPPY:confused: at ideal take the 1 belt off knock goes away

04-11-2013, 09:05 PM
My first thought was the harmonic balancer- I've seen several knock on start up, and shut down- on 3800 engines especially. And yes they can knock while running. They are about $120- well worth the try- the rubber element gets worn out and creates a metal to metal knock.

mopar man
04-11-2013, 09:20 PM
If the dealer says the bearings are bad the balancer could only be part of the solution I hate 3800s pieces of junk if ya ask me

Tech II
04-12-2013, 10:11 AM
Was this a GM dealer that dropped the pan and said the bearings were bad?

Normally, when you hear "knock" from a harmonic balancer, you will see a definite wobble from it as it rotates....by removing the belt, the noise can go way from a bad bearing....

As for the 3800 being junk, it's only major problem was that opening in the upper plenum in the EGR tube......if maintained, it was a solid engine, and could get 30 mph on the highway....had plenty of power, was easy to work on....

04-23-2013, 09:12 PM
Tech II Thanks for your help Today I pushed the Lesabre 3800 into position to jack it up Do you know if I need or what kind of puller I need the right front frame rail is about 4 inches from the harmonic balancer.Does the engine need to some out.I will probelily know more detail after I support it off the ground and look.Until then thanks all on the automotive forum

Tech II
04-23-2013, 09:49 PM
Universal three bolt puller will work......the center puller bolt will clear the inner fenderwell .......the three bolts that attach to the balancer will have to be short because one of them will be above the fenderwell, and as you pull it it will get close to the sheet metal.....but there is more than enough room....

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