3.8l engine noise help

Check to see if any of the Idler pulleys are worn & creating the "Noise" (IE: Bearing Noise). Next see if that isn't the problem if the Harmonic Balancer is at fault. The engine will run w/o either belt, but with out the Alternator belt on, you'll be using the battery to power everything. The SC belt can be removed safely for a short period of time (testing). You'll notice a lack of power though if the SC belt is removed.

Check to see that nothing is hitting the fan blades.

If there is room, and you can get a good grip on the belt tensioners, release the tension on the belt somewhat while the engine is running and see if the pitch of the noise changes or goes away. Be careful you don't slip off the tensioner nut or hex. whatever it is.

With the engine off you could also pull all the tension off the belt and spin the Altenator pulley, water pump pulley, power steering pulley, AC & supercharger pulley to see if there is a drag on any of them which could be a worn bearing.

Good luck

========= Harryface =========

So I can run the engine without any belt for a few minutes? Few minutes is all I need because the noise will start as soon as engine is idling. I am almost certain that it is not the water pump now because this noise just shows two days ago. I think you are right about the "harmonic balancer" because the noise is coming from the crank/water pump area possible AC. I have manipulated the tensioner using the wrench to push and lift slightly while the engine is idling to change belt tension to see if the noise would go away like Harry said. Nothing seems to help. I used a small metal tube and placed one of its end at various component such as alternator/ water pump housing belt tensioners and SC while the engine is idling and the other end at my ear to listen (attempt to use it as a steoscope). The sound from each component is normal. I could not place the tube to test the power steering pump , harmonic balancer or AC unit since it is out of my reach. So the only two potential areas where the noise could coming from is AC or harmonic balancer. If I remove the AC/SC belts, I could confirm this easily. Can I spray WD40 or penetrating oil behind harmonic balancer to see if I could change the noise? What could move behind harmonic balancer? Is the harmonic repairable and how simple is it?

Thanks for the info,

"DeathRat" wrote in message news:y2KKb.5528$X%5.1821@pd7tw2no...

"Paul" wrote in message news:3SIKb.15964$ snipped-for-privacy@news20.bellglobal.com... > I have noticed yesterday that there is an engine noise that sound like kid > on bicycle wheel with wooding stick that hit the spokes as it turn. I think > it either coming from a pulley tensioners, possible alternator or water > pump. I have two belts on this 1993 Bonneville SSEi model. One belt drives > an alternator and power steering pump that is driven from crankshaft pulley > while the other one drives AC, water pump and supercharge also driven from > crankshaft pulley. I would like to remove an alternator belt and power > steering to see if the noise go away for testing purpose only. I know if I > remove the water pump/ac and supercharged, the vehicle would not work. > So my question is can I do any damage to electrical or engine with > alternator belt remove for testing purpose? > Has anyone heard this noise before? > Could it come from timing chain's tensioner? > > P.s: If I increase the RPM to 1000, the noise would almost goes away and > while driving, I can not hear any noise. Also, oil pressure (more than > 275)and engine temperature are normal. Car performance is also normal. No > engine light . > > Paul > > > > Check to see if any of the Idler pulleys are worn & creating the "Noise" (IE: Bearing Noise). Next see if that isn't the problem if the Harmonic Balancer is at fault. The engine will run w/o either belt, but with out the Alternator belt on, you'll be using the battery to power everything. The SC belt can be removed safely for a short period of time (testing). You'll notice a lack of power though if the SC belt is removed.

Thanks for the info,

What usually happens with the Balancer is that it splits due to oil eating away at the rubber of the balancer. Therefore, it looses it "balance" factor & creates a noise from the bottom end.

I need because the noise will start as soon as engine is idling. I am almost certain that it is not the water pump now because this noise just shows two days ago. I think you are right about the "harmonic balancer" because the noise is coming from the crank/water pump area possible AC. I have manipulated the tensioner using the wrench to push and lift slightly while the engine is idling to change belt tension to see if the noise would go away like Harry said. Nothing seems to help. I used a small metal tube and placed one of its end at various component such as alternator/ water pump housing belt tensioners and SC while the engine is idling and the other end at my ear to listen (attempt to use it as a steoscope). The sound from each component is normal. I could not place the tube to test the power steering pump , harmonic balancer or AC unit since it is out of my reach. So the only two potential areas where the noise could coming from is AC or harmonic balancer. If I remove the AC/SC belts, I could confirm this easily.

change the noise? What could move behind harmonic balancer? Is the harmonic repairable and how simple is it?

away at the rubber of the balancer. Therefore, it looses it "balance" factor & creates a noise from the bottom end.

I'm kinda thinking the sound could be the crank sensor scrapping the shutters but thats usually a fast rotating scrapping sound.

I have ordered a new crankshaft pulley/balancer from GM (expensive pulley system!!!). It will take about two days. Can I still drive the car slowly (about 10 km each way) to go to work or is it too risky? Will the pulley brake apart that could damage the engine?

How about a bad coupler in the supercharger? Spin the bearing back and forth to see if there is any play in it.