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Ok so I’ve noticed a strange knock sound coming from engine during cold starts not really cold temp but after the truck sits for awhile 3 or 4 hours. After start you have the high idle kick in for a bit then once the idle drops back to 500 rpm or so I can here an intermittent knock or series of knocks coming from lower in the engine.  You can also hear some sort of actuator ticking away that’s not what I’m talking about. If you drive the truck for a while and stop you can’t hear the sound anymore until the next cold start. 

the engine is a 5.3 with 3.500 kilometres on it 

Posted

I have this exact same thing. Same mileage. AT4 5.3L. I couldn’t watch the video, won’t open, but it’s definitely the same as my issue.

 

Dealership told me it “may” be the fuel pump. In their words, the sound “could be” within tolerance, but GM is not willing to investigate unless it gets worse because chasing a sound could be very expensive and labour intensive. “You have a lot of warranty left, I wouldn’t worry about it yet.” Apparently there is some sort of bulletin that suggests the sound “could” be normal.

 

It’s loud and irregular, and more and more noticeable when as the weather gets colder.

 

 

 

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Posted
Ok so I’ve noticed a strange knock sound coming from engine during cold starts not really cold temp but after the truck sits for awhile 3 or 4 hours. After start you have the high idle kick in for a bit then once the idle drops back to 500 rpm or so I can here an intermittent knock or series of knocks coming from lower in the engine.  You can also hear some sort of actuator ticking away that’s not what I’m talking about. If you drive the truck for a while and stop you can’t hear the sound anymore until the next cold start. 
the engine is a 5.3 with 3.500 kilometres on it 

Have the same thing on my 18 5.3. Been like that since day one. 30k miles later it’s not any worse. Goes away when warmed up. Normal GM clunking/knocking IMO


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Posted

Have the same thing on my 18 5.3. Been like that since day one. 30k miles later it’s not any worse. Goes away when warmed up. Normal GM clunking/knocking IMO

 

 

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That’s a bit better to hear. Though for longevity of parts (I tend to keep my vehicles for 8-10 years) loud clunking tells me I’m going to have some significant wear/damage by that point, because let’s face it, loud clunking/ticking means parts contacting harder together.

 

My main worry was my in-law’s Ford had the same issue that they finally dealt with 3 weeks ago. Dealer ended up dropping him a new engine with only 4 weeks left on warranty.

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