O.T. 1999 3.1 Chev engine whine

IA Roy · Sep 15, 2011

Sometime back I began noticing a whine from the engine. First I thought it was the power steering pump. I replaced that with another used one. Then a couple of weeks later my alternator quit charging, so I replaced it. I don't think it is the water pump.
Currently I am thinking that the timing chain may be stretched to the point of rubbing on the front cover. Is this a reasonable possibility. I currently have 240,000 miles on it. I have had it over 200,000 of that and have not had to go into that end of the engine. The pitch of the whine changes with the speed of the engine.
thanks in advance for your replies, Roy

glennster · Sep 15, 2011

check the belt tensioner and any idler pulleys. could be the bearings are going out in them. loosen the serp belt and wiggle the pulleys side to side to check for slop, spin em to see if there is any roughness.

rlp in Co. · Sep 15, 2011

You can buy a stethoscope from harbor freight to check for noise. Also just a plastic hose works well too or you can just keep throwing money and parts at it and eventually you're bound to hit the right one.

bradk · Sep 15, 2011

I agree w/glennster.Take the belt off and spin all pulleys by hand.A cheap automotive stethoscope would be pin-point the noise too.

Timing chains in the 3.1"s aren"t a problem,even with high miles.

Allan in NE · Sep 15, 2011

Agree with the other guys.

That sure sounds like a belt issue somehow somewhere. Haven't just changed it fer a 'cheap' belt or used some magic belt-dressing have ya?

Take the belt off and start 'er up to see if the noise goes away.

Had a 'tick' in an engine one time. Ended up being a tiny, tiny piece of gravel in the drive pulley. Could not get that sucker out and had to replace the whole derned pulley.

Allan

dhermesc · Sep 15, 2011

I agree too, but taking the belt off and spinning them by hand won't do you much good. The belt (or pulley) is making a noise while under tension with it idling at several hundred RPM. Get your stethiscope up there while its idling.

I just replaced an idler pulley to fix a very noticable whine on my wife's minivan that a "mechanic" tried to convince her was coming from the transmission. He just about had her roped into a $340 transmission flush (that should only cost $120) when she called me to see if it was OK.

bradk · Sep 15, 2011

"taking the belt off and spinning them by hand won"t do you much good"

Sure it does.Those little bitsy idler and tensioner pulley bearings are real easy to diagnose good or bad with no belt or tension on them.A flick of the finger gets "em going pretty good to see if they "sing" to you.

504 · Sep 15, 2011

To check the belt start the car and spray anything on the belt(WD-40,window cleaner,brake clean etc. ) if the noise changes you have found the problem, if not it was a quick way to check the belt.

RusselAZ · Sep 16, 2011

I'll say you need to check the battery. Batteries have a habit becoming resistors and will cause alternators to have to constantly put out a high amp load.

O.T. 1999 3.1 Chev engine whine

IA Roy

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glennster

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rlp in Co.

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bradk

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Allan in NE

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dhermesc

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bradk

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504

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RusselAZ

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