Slight Knock After A Long Tow

Hey guys,

I recently towed my wakeboard boat out (bout 250 miles each way) a few weeks ago and was going up a huge 20 mile hill and started hearing some weird noises from the engine bay whenever I'd give it a good amount of gas to speed up. It was about 105 at night time. I eased off the rest of the way there and back and didn't really hear any noises but when I got back home I noticed a slight knock in the engine bay. The next morning when I started it up it was gone but it comes back after driving for 15 20 miles or so. Only does it at idle.

I attached a video you can hear. Try to hear past the valve, injector and spark noise and you'll hear a deeper rattle/knocking.

I took it into the dealer though and they couldn't get it to happen again. Of course as soon as I took it home it happened again.

Any ideas of what it could be? The truck has 30k miles..

https://vimeo.com/137318816

Bump!

Sounds like Hemi tick plus something really f'd up like the cam lobe or something. Glad you are under warranty, it wont likely be long before something gives. Curious, what oil and filter do you use? Unless I am hearing something from your mic, that background cadence secondary to standard hemi tick sounds bad. When was last oil change?

Hmm yeah and the tick sounds a bit louder on the driver side too. Worried something's going to give the next trip with the boat. But unfortunately it's intermittent and the dealer couldn't get it to make the noise. I use valvoline full synthetic. Change every 5-7k miles with Bosch or molar filter

scnautique said:

Hmm yeah and the tick sounds a bit louder on the driver side too. Worried something's going to give the next trip with the boat. But unfortunately it's intermittent and the dealer couldn't get it to make the noise. I use valvoline full synthetic. Change every 5-7k miles with Bosch or molar filter

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I recommend going to another brand oil like Mobil 1 and maybe bump the weight grade to 5W-30 if allowed and go from there. While I am sure Valvoline Synthetic meets the "specs", some oils just perform better in some engines when it comes to noise and ticks like this.

Hootbro said:

I recommend going to another brand oil like Mobil 1 and maybe bump the weight grade to 5W-30 if allowed and go from there. While I am sure Valvoline Synthetic meets the "specs", some oils just perform better in some engines when it comes to noise and ticks like this.

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Maybe so, but oil weight and brand to me shouldn't have to be changed for a motor with 30k, especially when it's a pretty well-reputable synthetic.. Right? I've ran this oil for 20k miles so far

scnautique said:

Maybe so, but oil weight and brand to me shouldn't have to be changed for a motor with 30k, especially when it's a pretty well-reputable synthetic.. Right? I've ran this oil for 20k miles so far

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Check out the synthetic oil thread. It's long but its got a ton of great info about oil. Try switching to a Pennzoil product or better yet Redline.

My truck was the quietest overall on Pennzoil conventional or Yellow Bottle.

Pennzoil Platinum or Ultra are also great choices although it made mine louder. Others it made quieter.

If the noise is intermittent, its worth a shot changing the oil before going to the dealer.

scnautique said:

Maybe so, but oil weight and brand to me shouldn't have to be changed for a motor with 30k, especially when it's a pretty well-reputable synthetic.. Right? I've ran this oil for 20k miles so far

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In a perfect world, I agree it should not matter. The simple fact is every engine wears in different. While each oil company for a given weight and API spec should all be the same, they each go about it different how they get to that spec with their formulation. It is pretty well reported on many of the Oil related and other automotive boards, that simple changing weight and/or brand has helped in reducing or eliminating minor or not readily repeatable ticks and noises.

In some circles, Valvoline is critiqued heavily in how they formulate to meet their specification as listed. Unless you can get it readily repeatable to have a dealership deep dive the issue, I think it work a shot to at least change brands to maybe Pennzoil Ultra or Mobil 1 for a oil change interval and at least get that data point. If allowed, I would also say go up in weight.

Hey all. I actually wanted to revive this thread from a long time ago. I just picked up a 2012 1500 with the 5.7 (this is now my third 4th gen truck lol) and realized I posted something similar about this with another truck.

Two out of three 4th gen trucks that I have had now do this at idle - it's a slight knock and a tad bit of a rough idle. My 2013 did it, my 2014 did Not do it and now my 2012 does do it. It's NOT the tick and not the manifold bolts so please don't suggest that!

My most current truck has 85k miles on it but I think it's maybe a similar issue. I'm running Pennzoil platinum with the Mopar filter in it right now fyi. I've also cleaned the throttle body, replaced the intake related sensors including the PVC valve with no luck.

Anyone else's truck do this? Any suggestions?

I didn't take a video of my own but found one that sounds very close.