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Discussion Starter · #1 · (Edited)
Hi all I have a 98 Olds 88 with the K engine. About 3 or 4 weeks ago the engine started making a noise after running for few minutes. It sounds like a dry v belt squeal, but this afternoon I pulled the new serpentine belt, ran the engine for about a minute and the noise is still there.

If you start the car when cold and just idle the engine, this noise isn't there. When you rev the engine to 3 grand or so, the noise comes in and stays there. Stop the engine, restart, and it's still there.

The car has 130,000 on it. My son is taking the car to school in a couple of days, so since it is going to be going out of state I

Changed the timing chain, gears, tensioner, and front seal. I changed the water pump, thermostat, and all the hoses, as well as the elbow between the lower plenum and tensioner assembly that fell apart. I did an oil change, while the front cover was off, I checked the oil pump clearances, they were great, and I cleaned up the cover inside and out. I changed the plugs, and pvc since it had been a couple of years. Changed out the serpentine belt, idler pulley, fuel filter, tranny filter and fluid, and did a brake job on the front, flushed fluid front and back. So the car has had a good going over.

The noise has been doing this for 3 to 4 weeks before all this work and still does it after all the front cover work. I sounds like it is coming from the lower front cover area, and with the serpentine belt on or off, the noise sounds the same.

Any ideas?
Thanks.
 

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Is it high pitched like sheet metal hitting something? possibly the crank sensor and the harmonic balancer getting a little close and hitting?



Hi all I have a 98 Olds 88 with the K engine. About 3 or 4 weeks ago the engine started making a noise after running for few minutes. It sounds like a dry v belt squeal, but this afternoon I pulled the new serpentine belt, ran the engine for about a minute and the noise is still there.

If you start the car when cold and just idle the engine, this noise isn't there. When you rev the engine to 3 grand or so, the noise comes in and stays there. Stop the engine, restart, and it's still there.

The car has 130,000 on it. My son is taking the car to school in a couple of days, so since it is going to be going out of state I

Changed the timing chain, gears, tensioner, and front seal. I changed the water pump, thermostat, and all the hoses, as well as the elbow between the lower plenum and tensioner assembly that fell apart. I did an oil change, while the front cover was off, I checked the oil pump clearances, they were great, and I cleaned up the cover inside and out. I changed the plugs, and pvc since it had been a couple of years. Changed out the serpentine belt, idler pulley, fuel filter, tranny filter and fluid, and did a brake job on the front, flushed fluid front and back. So the car has had a good going over.

The noise has been doing this for 3 to 4 weeks before all this work and still does it after all the front cover work. I sounds like it is coming from the lower front cover area, and with the serpentine belt on or off, the noise sounds the same.

Any ideas?
Thanks.
 

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Sometimes main bearing noise sounds like squeaking. After a while it turns into knocking. Not all the time but sometimes. My 94 Olds 98 did it. So did my Escalade.
 

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Discussion Starter · #5 ·
I'll check the oil cap idea, and the crank position sensor tomorrow and get back to you.

I am also going to check the oil pressure with a direct reading guage tomorrow.
 

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Discussion Starter · #6 · (Edited)
Crank position sensor ok.

They at my friends shop put it on the lift this morning and started it up and let it idle. It ran 30 min no noise, then it started making the same noise and did so all day. The seem to believe it is coming from the torque converter / bellhousing area. They pulled the little shield on the bottom of the tranny, all the converter bolts are tight, and nothing rubbing that they could see. The crankshaft thrust fore and aft was good within specs...

Oil pressure cold idle 60 psi. Hot idle 55 psi.

When I pulled the trans pan for the service last weekend, the pan was bout clean as you could want. No debris or shavings on the magnet, the fluid was still fairly clear and no burned smell.

I will check the oil cap thing tomorrow, I have the car back and we are driving it about 800 miles over the next 2 days to bring him to college.
 

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Discussion Starter · #7 ·
Yes, the noise does go away when I took the oil cap off.

We got the car back late afternoon yesterday. Loaded up the truck and trailer and headed out this morning. Put about 530 miles in today.

I stopped for gas after 200 miles for the truck, I checked the fluids on the Olds, and had my son start it up. It was making the noise as strong as ever, and when I pulled the cap, the idle speed dropped same as every other time, but the noise did stop. I revved the engine a little and no noise until I put the cap back on.

I'll do a search, but what gives?
 

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PCV system plugged in the TB or something?
 

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Discussion Starter · #9 ·
There isn't a 0 ring around the PVC or a spring between the PVC and the cover. Never has since I bought the car used in 02..

The Blockage everyone seems to be talking about, I did run the engine with the PVC out 1 day and there is vacuum under where the PCV sits at. The PCV sits on 1 end of the upper plenum, the throttle body at the other. Do I need to pull the throttle body off and check for carbon plugging or something? There is a passage between the PCV end and the TB on the other end of the engine.

I'll have to see if there is someplace up here in Tulsa that I can work on the engine at. I don't know if I can at my son's apt complex. We are moving in tomorrow, that would make a great 1st impression! I hope I don't need to pull the upper plenum.

Thanks for all the help though....
 

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I would think it is not the PCV side, but the air intake side, which on the older 3800's was in the rubber before the TB, but I think later was in the TB.

Look for that line, so if the PCV is sucking like it should, then crankcase pressure will be going negative, and if there is no way to get air in, SOMEWHERE will leak, the moving crank is the easiest place if the rest is sealed good.

If you can't deal with it right now, go find a breather for a old V8 like the old school engines had, vented. So it pulls in air at the oil filler.

If you can't, you can modify the oil cap to be vented, say a small hole and a vacuum line that dumps under the car away from the exhaust or someplace that could create a fire if oil came out (it shouldn't, but oil can under some conditions if rings are weak).
 

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Discussion Starter · #11 ·
I dont think IIRC that it has the external line for the PVC, it must be in the throttle body. So if the engine is sealed up that well, that is why the noise sounds like it is either coming from around the damper or the torque converter.

Wow.

I'm going to look for the o ring, spring, and a TB gasket at a dealer either here or in Tulsa, If I can find a place that i can pull the TB when we get there I'll take a look then or make a vent.

Wow...
 

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im pretty sure that there is a tube that goes from the pcv to like the middle of the plenum. it doesnt go back to the throttle body. did you make sure the pcv itself is good. i would try replacing it.
 

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I have an L36 throttle body gasket in the for sale section right now

I dont think IIRC that it has the external line for the PVC, it must be in the throttle body. So if the engine is sealed up that well, that is why the noise sounds like it is either coming from around the damper or the torque converter.

Wow.

I'm going to look for the o ring, spring, and a TB gasket at a dealer either here or in Tulsa, If I can find a place that i can pull the TB when we get there I'll take a look then or make a vent.

Wow...
 

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Discussion Starter · #14 ·
89017274...

I did change the PVC over the weekend. No change. But that PCV has not had a o ring around it since 2004 or so. I did look again this morning at the upper plenum and the air cleaner assy/ inlet boot. Nothing external for the air to the PVC to be seen..

I looked for a Buick/Pontiac dealer in the yellow pages and found 1 a few miles from the hotel in Little Rock. Asked for a oring for the pvc, spring, and new cover assy. They had a valve kit for $27 that had both o rings, the spring, the cover and a new PVC.

Kindly thanked the man, took my kit out into the parking lot and changed the lot out. I did have a spring in there, but compared to the new one it had maybe 1/2 the tension? Plugged everything in, started the engine, and........
..............................................................................................

No noise. waited, revved the engine. No noise. Pulled the oil filler cap, and the engine speed didn't decrease like it has been before. Drove west 100 miles or so, stopped, no noise.

Thank you everybody. It has taken a load off of me, knowing the car is noise free, and as in a good mechanical condition as I can get it.

Thanks.
 

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cool!!!!
 

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Just went through the upper & lower intakes on a 2004 Lesabre at 90k miles. It had the metal lower gaskets as assembled by GM and the pipe coming through the plastic upper manifold had good clearance. I had purchased a new APN Upper intake manifold so went ahead and put it on even though it didn't appear to be necessary. A day or two after the rebuild the engine started squealing like a banshee. We looked all over and could swear it was coming from the flex plate/torque converter area. Read this post and took the oil fill cap off. The open hole was sucking like a very strong vacuum cleaner and the engine quickly died. Have you figured out the answer yet?

I forgot to transfer the PCV and spring from the old UIM to the new one. After that she purred like a kitten! Thanks for pointing me in the wright direction!!!
 

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Discussion Starter · #17 · (Edited)
Yes sir. The car has not made any more of that noise since Oct 2009. None in almost 5 yrs, I believe it is a combination of the kit, mainly the new spring, o rings and and the new cover. Between the 3 components it cleared it up. But yes sir, the kit fixed it. It was worth the $27 in 2009 dollars.

And after re-reading the thread from the beginning instead of trying to remember the event, air was trying to rush in by the crank seals from the weak spring / no oring seal at the PVC seat.

It is amazing that this thread is almost 5 yr old.. We still have the car. it is well in the 180k miles range. My daughter has it now. Wrecked it 2 times, but it still runs straight, and is reliable. It does use a little water from time to time, but a snug of the upper plenum and it stops any coolant useage. It uses little oil. but only between oil changes. Since she uses it now, the brake wear has returned to normal. Chalk that up to a son who used the brake to regulate his speed.... He is paying for his own car now ! And his own brakes too !


Still, It is The best engine or 1 of the best I believe I've ever owned.

I am glad we were able to help out. I hope you get the mileage and service from yours that we have.. And thank you again guys for the ideas & the offer of parts. It was good to have a place with good people to bounce ideas off of.
 

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Just adding this. I had the same problem and had tried all of the same fixes with no luck. In my car’s case the passage in the upper intake plenum had become clogged with the oil/coolant residue from the stovepipe problem that allowed the coolant and oil to mix. (Well documented problem)
When the car was cold it would create a strong vacuum in the oil tank but, as it warmed, a pinhole would open in the clogged passage creating an infuriating and unfindable sound. At first it sounded like a belt squeak but in warmer weather it could develop into a howling sound.
I fixed this by replacing the upper manifold plenum.
 
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