Author Topic: Does anyone know what this sound is?  (Read 2631 times)

Offline audrima

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Does anyone know what this sound is?
« on: November 11, 2017, 04:08:35 PM »
hello all,

My truck( 1978 GMC C25 hd with a 350 Qjet) is making a weird noise. and I don't know what it is. I'm thinking rocker is lose.
here is 2 clips  to hear it.

https://www.dropbox.com/s/xs7orold7qkxb7j/20171111_155044.mp4?dl=0

https://www.dropbox.com/s/92ynbs1q09b7y4o/20171014_122947.mp4?dl=0

don't know and I need to drive her to nyc very soon and tow a Subaru home.
any home will be welcome thanks!

Aud
« Last Edit: November 11, 2017, 04:21:29 PM by audrima »

Offline VileZambonie

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Re: Does anyone know what this sound is?
« Reply #1 on: November 11, 2017, 04:59:28 PM »
Did you check the oil?
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Offline audrima

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Re: Does anyone know what this sound is?
« Reply #2 on: November 11, 2017, 05:06:09 PM »
oil is full of 10w40 (though it is 2 years old but only 800 miles.)

Aud

Offline zieg85

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Re: Does anyone know what this sound is?
« Reply #3 on: November 11, 2017, 05:09:13 PM »
I hear an exhaust leak, loose alternator belt and a noisy lifter
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline VileZambonie

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Re: Does anyone know what this sound is?
« Reply #4 on: November 11, 2017, 05:11:21 PM »
Does it have an oil pressure gauge? Does it read pressure? If so, pull the valve cover, make sure oil is coming to the rockers, check valve adjustment. What kind of oil have you been using?
,                           ___ 
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              ⌠ŻŻŻŻŻ'   [☼===☼]
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline audrima

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Re: Does anyone know what this sound is?
« Reply #5 on: November 11, 2017, 05:20:13 PM »
there is a exhaust leak, but its taped up, sooo need a new y pipe.  I'll check the belts I did just change the water pump. I hope it's something easy like a lifter!  The oil when I first start is at 60 but after it warms up (or about 20 min) is goes and stays at 40 (in the middle). i it has pensoil 10w40 right now. about 800 miles since it was change...2 years ago (almost 3) this truck has had pensoil all it's life.

thank you for your replies.

Offline FlatBlack77

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Re: Does anyone know what this sound is?
« Reply #6 on: November 11, 2017, 05:57:11 PM »
I wouldnt call replacing a lifter an easy job. not extremely difficult but its not just a few bolts kinda job.

I would pull the valve cover like Vile said. might aswell do both. make sure everything is getting oiled and youll probably be able to find the loose one very easily
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Offline audrima

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Re: Does anyone know what this sound is?
« Reply #7 on: November 11, 2017, 06:05:26 PM »
Well easy compared to replacing the whole engine. valve covers come off tomorrow (if there is money in the bank lol)

thanks everyone

Aud

Offline Engineer

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Re: Does anyone know what this sound is?
« Reply #8 on: November 11, 2017, 06:36:43 PM »
Give each of your rocker nuts a 1/4 turn and see if that quiets the lifter.
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Offline audrima

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Re: Does anyone know what this sound is?
« Reply #9 on: November 11, 2017, 07:17:14 PM »
I will do that thank you


aud