2004 Buick LeSabre engine noise

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Gerry
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Joined: Wed Jul 09, 2014 1:58 pm

2004 Buick LeSabre engine noise

Post by Gerry » Wed Jul 09, 2014 2:38 pm

I have a 2004 Buick LeSabre with a 3.8L V6, with 159,000 miles. After changing plugs, oil, filters last Nov. the idle speed dropped to what I guess is about 600-650 rpm. It started to make a high pitch squeel, intermittently, on deceleration (only at mid level engine temperature), like the belt was bad, changed it and still there. Changed idler pulley, still there. Live in Buffalo and wasn't going to deal with it in the winter unless I had to. (took a trip to Virginia and it never made the noise) This spring at inspection, my mechanic swore it was the belt, but didn't have time to do it. I changed it again, noise still there. Went back to him and he tried to tell me it was an engine mount! The noise happens almost all the time now when you come off the gas, when mid to full operating temp. Now does it in park at 3/4 temp, then stops unless in gear coming off the gas, stationary or moving. I used a regular stethoscope and it sounds like it is coming from the timing cover, or, more likely the cam area. Incidental - A/C clutch was not engaging until I added freon, super stop leak, freon (not staying cold, but, clutch engages) noise never went away! Do you think it could be oil pressure to bearings? Would changing oil weight help? Oil pressure warning NEVER came on, and so far performance is not affected. Any ideas?

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karlk
Posts: 87
Joined: Fri Dec 27, 2013 7:39 pm

Re: 2004 Buick LeSabre engine noise

Post by karlk » Thu Jul 10, 2014 9:28 pm

The first thing i would do is remove the belt to see if the noise goes away. That would for sure rule out the belt, all pulleys and all accessories.

If you hear it in the timing chain area, it is possible that the chain is stretched. This is not very common on the 3800, but possible.

I dont think a motor mount can give you the noise you are getting on your Buick.

Does not sound like an oil pressure or bearing problem either. Being intermittent will make it hard to find.

Have had a few problems with one of the O' rings on the PCV valve being ripped or just brittle. This can cause a whistle type sound. I would remove the PCV valve and check them.

Gerry
Posts: 2
Joined: Wed Jul 09, 2014 1:58 pm

Re: 2004 Buick LeSabre engine noise

Post by Gerry » Thu Jul 31, 2014 12:58 pm

Thanks for the feedback. The problem with removing the belt is that the noise is intermittent, so I wouldn't really know if that is the answer. Only if it makes the noise without the belt. I checked the PCV valve (it sounded really logical) everything is intact and the noise is not coming from the area when checked with stethoscope. Tried belt dressing, cause why not-nothing else has worked, helped for a short period but didn't fix it. This last time the noise sounded like it was coming from the area of the PS unit, but, no noise when cranking steering hard right or left. My big concern is that it could be coming from the transmission because the majority of the time it only happens when in gear. I have been fixing my own cars for 35yrs and never heard a classic belt noise come from the transmission, but never say never! Any one else have any ideas?

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butch
Posts: 90
Joined: Mon Dec 23, 2013 4:14 pm

Re: 2004 Buick LeSabre engine noise

Post by butch » Sun Aug 03, 2014 7:01 pm

If it is intermittent, then yes it could be a transmission problem. Check the fluid level first.
On decel, the fluid sloshes in the pan, it is possible the seal on the filter is bad so the trans sucks air. This will cause a noise. If you could post a video so we can hear the noise, that may help.

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