Trying to figure out THIS noise. |
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Trying to figure out THIS noise. |
Rob-O |
Dec 15 2019, 03:46 PM
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#1
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Senior Member Group: Members Posts: 1,251 Joined: 5-December 03 From: Mansfield, TX Member No.: 1,419 Region Association: Southwest Region |
At its loudest when I pull to a stop and the car is idling. After 20 seconds of this sound at idle it usually goes away. Revving the motor gives mixed results. Sometimes the noise rises with the rpms and then goes away. Other times it goes away almost immediately when the rpms start to rise.
I thought the oil level might be low and I was starving the motor but oil level is fine. Of course that doesn’t mean that the oil pump is pumping volume but at least the level is fine. Only things that I’ve changed or adjusted before the noise started were: 1. Changed to a different AFM. Thought this might be detonation but the mixture screw is turned all the way in. So if anything it should be running rich with the mixture screw all the way in. 2. Timing was checked and adjusted. This noise is present at 8 deg. BTDC (stock setting) and 4 deg. BTDC. 3. Added heating ‘j’ tubes, flapper boxes and the rest of the associated hardware to the drivers side. Incidentally it *almost* sounds like the noise is coming from the drivers side. I thought it could possibly be the small flap that cuts off air going to the heat system at idle. But it just sounds too loud for that and even if it was that flap would really have to be snapping back and forth a bunch. https://youtu.be/ELe26KeljpU |
iankarr |
Dec 15 2019, 04:17 PM
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#2
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The wrencher formerly known as Cuddy_K Group: Members Posts: 2,471 Joined: 22-May 15 From: Heber City, UT Member No.: 18,749 Region Association: Intermountain Region |
Tough to tell from the clip, it sounds like a noisy valve or maybe an un-pumped hydraulic lifter. Do you have hydraulic lifters? Strange that it’s intermittent.
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Beebo Kanelle |
Dec 15 2019, 04:31 PM
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#3
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Member Group: Members Posts: 248 Joined: 22-November 12 From: Houston, Texas Member No.: 15,177 Region Association: Southwest Region |
My money is on the bad lifter hypothesis.
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rjames |
Dec 15 2019, 05:45 PM
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#4
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I'm made of metal Group: Members Posts: 3,914 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest |
Tough to tell from the clip, it sounds like a noisy valve or maybe an un-pumped hydraulic lifter. Do you have hydraulic lifters? Strange that it’s intermittent. Agree with all of this. Sounds like a hydro lifter that’s not pumped up, that is, until it starts making the sound intermittently and at a different speed than the engine rpms, but maybe that’s just the recording. If it’s a lifter, the noise will speed up/slow down in conjunction with the engine rpms. Make sure your valves are adjusted correctly. Gap is different for hydraulic lifters (if that’s what you have). |
ClayPerrine |
Dec 15 2019, 07:44 PM
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#5
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Life's been good to me so far..... Group: Admin Posts: 15,410 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille |
Want me to come listen to it?
Clay |
djway |
Dec 15 2019, 08:05 PM
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#6
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Senior Member Group: Members Posts: 787 Joined: 16-October 15 From: Riverside Member No.: 19,266 Region Association: Southern California |
1.Valve adjustment
2.Alternator bearing My bet is one |
second wind |
Dec 15 2019, 08:08 PM
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#7
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Senior Member Group: Members Posts: 850 Joined: 30-December 10 From: Los Angeles, California Member No.: 12,543 Region Association: Southern California |
My car would do intermittent noise similar to yours and would go away but come back. Bad valve seat was the culprit. Sorry about the bad guess but just sharing my exp.
gg |
Rob-O |
Dec 15 2019, 09:41 PM
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#8
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Senior Member Group: Members Posts: 1,251 Joined: 5-December 03 From: Mansfield, TX Member No.: 1,419 Region Association: Southwest Region |
I appreciate all the replies. I thought valve adjustment, too. Initially I thought odds of it coming from the valve train was low. My reasoning was that a valve adjustment was done not that long ago. Second was that the sound just kind of came out of nowhere. I figured valve train would start low and over time get louder. This was more not there one day and then there the next.
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Rob-O |
Dec 15 2019, 09:42 PM
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#9
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Senior Member Group: Members Posts: 1,251 Joined: 5-December 03 From: Mansfield, TX Member No.: 1,419 Region Association: Southwest Region |
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second wind |
Dec 15 2019, 09:43 PM
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#10
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Senior Member Group: Members Posts: 850 Joined: 30-December 10 From: Los Angeles, California Member No.: 12,543 Region Association: Southern California |
Alternator belt? Let's hope....
gg |
rjames |
Dec 15 2019, 11:50 PM
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#11
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I'm made of metal Group: Members Posts: 3,914 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest |
So do you have hydro lifters?
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porschetub |
Dec 16 2019, 12:41 AM
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#12
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Advanced Member Group: Members Posts: 4,697 Joined: 25-July 15 From: New Zealand Member No.: 18,995 Region Association: None |
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Rob-O |
Dec 16 2019, 08:14 AM
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#13
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Senior Member Group: Members Posts: 1,251 Joined: 5-December 03 From: Mansfield, TX Member No.: 1,419 Region Association: Southwest Region |
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TheCabinetmaker |
Dec 16 2019, 08:41 AM
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#14
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I drive my car everyday Group: Members Posts: 8,300 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
Typical of a loose valve seat. Hasn't completely dropped yet, but sliding in and out of it's recess.
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rhodyguy |
Dec 16 2019, 09:23 AM
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#15
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,060 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
Have you had the HE's off?
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KSCarrera |
Dec 16 2019, 09:56 AM
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#16
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Member Group: Members Posts: 307 Joined: 31-January 19 From: UK Member No.: 22,846 Region Association: England |
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Rob-O |
Dec 16 2019, 09:18 PM
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#17
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Senior Member Group: Members Posts: 1,251 Joined: 5-December 03 From: Mansfield, TX Member No.: 1,419 Region Association: Southwest Region |
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Rob-O |
Dec 16 2019, 09:19 PM
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#18
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Senior Member Group: Members Posts: 1,251 Joined: 5-December 03 From: Mansfield, TX Member No.: 1,419 Region Association: Southwest Region |
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