Gas engine sounds like a diesel engine at low idle?

2013 VOLKSWAGEN PASSAT

150,000 MILES • 2.5L • 2WD • AUTOMATIC

PHILMARVT

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Hi folks.
I have a question about my grandson's car listed above. It sounds like a diesel engine at low idle but it's a gas engine. We have taken it to two different shops, but they can't figure it out either. At low idle it really sounds like a diesel engine. But if you touch the gas just a tiny bit the noise goes away. Standing in front of the engine it's hard to tell if it's coming from the left side, right side or from the top. We are not getting any error codes or warning lights on the dash. The car seems to run fine. No smoke out of the exhaust, nothing leaking, etc. I'm attaching a short video of the noise. Any thoughts or ideas would be greatly appreciated.
Thanks
Phil

Video (Click to enlarge)

Nov 17, 2022 at 5:45 AM

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Thanks for the video, it really helps when it comes to noise. The engine noise in the video is caused by the timing chain guides are worn or broken. I have included the timing chain and guide replacement diagrams and instructions in the images below. Check out the images (below). Please let us know if you need anything else to get the problem fixed.

Images (Click to enlarge)

Nov 17, 2022 at 12:20 PM

PHILMARVT

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Hi Ken,

Thanks for your prompt reply. Just a few more follow up questions:
1.So if we change the timing chain guides it should solve the problem?
2.Should we change the timing chain and chain tensioner while we are at it?
3. What could happen if the chain guides aren't replaced?
4. Is this a hugh job if done by a shop?
Thanks again,
Phil

Nov 17, 2022 at 1:03 PM

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Yes, it is a good size job, and yes, I would do the chains, guides and tensioner. If you let the job go it will end up breaking something and the engine will need to be replaced if this happens.

Nov 17, 2022 at 5:15 PM