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6.2L Tapping noise

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Old 12-12-2013, 03:16 PM
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Default 6.2L Tapping noise

In October I posted a question if anyone has had problems with lifters in a 6.2L. I finally took it in to the dealer after the noise getting worse. Sounds like a diesel going down the street after cold starts. I am being told that GM wants to have the oil pump replaced. So I am waiting for that to get done and go from there... no TSB on this.
Old 12-12-2013, 05:56 PM
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did they say the pump failed for sure? valvetrain oilpressure test?
Old 12-12-2013, 05:56 PM
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I have been seeing a lot of tapping noises due to blown out lifters and worn camshafts
Old 12-12-2013, 06:38 PM
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I wonder how much debris was sent through the motor if the oil pump wasn't working properly.
Old 12-12-2013, 07:46 PM
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There seems to be an issue with the oil pump relief valve sticking. The process is to replace the pump, change the oil and filter, and recheck. Not only because this is the second time this has happened ( 2008 Denali XL rocker arm broke #2 and replace camshaft). I am in the business so I know more than the average customer.
Old 12-12-2013, 07:48 PM
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Reason it makes noise on cold start and first drive off, oil is cold. Cold oil is thicker till it warms up.
Old 12-12-2013, 08:22 PM
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Originally Posted by SDenali12
Reason it makes noise on cold start and first drive off, oil is cold. Cold oil is thicker till it warms up.

reason the lifters make noise on cold start is the bleed down is excessive in the AFM lifter thus making the rattle or tap for 2-60 seconds on start up. that applies for lifters but has nothing to do with engine oil being cold
Old 12-12-2013, 08:24 PM
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I have replaced many of these in 5.3's 6.0's and 6.2's with this issue but if you are having oil pump relief valve sticking I am just wiondering did they do a mechanical oil pressure check on both the lower end and the valvetrain? and was there any metal contamination from lack of lubrication?
Old 12-12-2013, 08:25 PM
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as for the lifters with a tech 2 you can deactivate and active AFM lifters in v4 mode etc and listen for the tapping noise
Old 12-12-2013, 08:29 PM
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that PIP u are talking about are they flushing the oil cooler lines if equipped and replacing the Oil pressure sensor as advised in the PIP, and cleaning the oil pan?
Old 12-13-2013, 01:34 PM
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Not an AFM engine. According to the doc. with changing the pump, they are supposed to flush lines if equipped, and clean inside of oil pan. I should be able to tell what they did by the parts charged on the invoice. However, yes I am aware that because a part is on there does not mean it was used.
Old 12-16-2013, 10:14 PM
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Default 6.2L Tapping noise update

Update on repairs... oil pump replaced. Now they are gonna replace lifters. I had already told them they need to remove and mic the camshaft.



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