[laid_back_luke]

My 2014 2500 3.6L with 161K on it has developed what seems to be a engine knock. Am I screwed?

I recently drove the van across country to Utah and after a few weeks of living here I started noticing the sound.

I have not done the oil since arriving but changed it a few days before our trip across. The van seems to run fine overall but sounds awful. The noise seems to dissipate at speed. I do have 2 codes, a P0420 - Catalyst system below threshold Bank 1 and P0430 -Catalyst efficiency bank 2.

I have not been able to diagnose if there is an exhaust leak due to the recent weather out here but it seems like it could be more than a minor issue.

link to video filmed today.

3.6L Pentastar Engine Knock

youtube.com

 

[[email protected]]

Sounds like a pretty bad pentastar 3.6 engine tick. Could just be the rockers need replacement if the cam is still in good shape.

This youtube video has an example of the noise on what appears to be an early detection of the tick, go to 2:00 to hear the sound. This is the same engine you have in the van.

Pentastar Engine Tick

 

[laid_back_luke]

Sounds like a pretty bad pentastar 3.6 engine tick. Could just be the rockers need replacement if the cam is still in good shape.

This youtube video has an example of the noise on what appears to be an early detection of the tick, go to 2:00 to hear the sound. This is the same engine you have in the van.

Pentastar Engine Tick

You may be right and the that video showcases the tick well but not the deeper knock (sounds kind of like its a bad an exhaust leak). Is anyone aware if it the tick can become deeper if it totally fails?

 

[phil]

could ask @Kip-on-truckin for his opinion

short video toward the end you hear the "deeper knock noise"
3.6L Pentastar Engine Knock

 

[Kip-on-truckin]

Limited information, but the symptom/sign of the pentastar tick is a single cylinder misfire. If it gets bad enough, it will CAUSE cat codes (P0420,P0430) as the unburned fuel from the misfire gets into the cat. In this case though, your problem is more likely to be something other than the tick, because you have those codes in isolation. And that you have codes for BOTH cats at once is very telling. Given that your complaint is noise, I'm guessing you have an exhaust leak that's allowing BOTH cats to give wonky readings. There are other possibilities - it could be overfueling which would do that too, but it would result in other codes as well. Too much fuel would also sound loud and blatty, and you'd likely see black smoke or soot out of the pipe. The root cause of this problem is likely something very simple - an unplugged connector could make it overfuel, a wiring issue at the main computer.

 

[laid_back_luke]

Limited information, but the symptom/sign of the pentastar tick is a single cylinder misfire. If it gets bad enough, it will CAUSE cat codes (P0420,P0430) as the unburned fuel from the misfire gets into the cat. In this case though, your problem is more likely to be something other than the tick, because you have those codes in isolation. And that you have codes for BOTH cats at once is very telling. Given that your complaint is noise, I'm guessing you have an exhaust leak that's allowing BOTH cats to give wonky readings. There are other possibilities - it could be overfueling which would do that too, but it would result in other codes as well. Too much fuel would also sound loud and blatty, and you'd likely see black smoke or soot out of the pipe. The root cause of this problem is likely something very simple - an unplugged connector could make it overfuel, a wiring issue at the main computer.

@Kip-on-truckin Thanks for the reply! Your feedback is along the lines of what I was thinking. I have not seen any black smoke out of the exhaust and I even changed the Purge Control Solenoid as I thought maybe it failed and was throwing the air/fuel ratio off. I am leaning toward an exhaust leak because I have detected a slight exhaust smell under the hood but it's not constant so its hard to tell if it was just the wind where I was parked. I have also not gotten any misfire codes, do those exist on promasters? I guess I should maybe check the plugs while I am at it?

To add a bit more information, I was living on the east coast at sea level but drove it across the country to Utah where I now live at 7500ft. The noise was not there when I left and only became noticeable after driving around while living in Utah. I have put on about 3K miles since doing the oil change (back east). I thought it would have been weird for the tick to start after the trip seeing as it was constant highway driving with fresh oil and no long periods of idling. I also lean toward exhaust leaks because all roads seem to suck so wouldn't be surprised if something rattled loose or broke free on the exhaust.

One other thing I noticed yesterday was my oil level seemed like it may be a little high. I plan to do an oil change once the weather allows me.

Any chance you know a solid mechanic familiar with the 3.6 in the SLC area? My hoa is super strict about working on anything in my parking lot.

Here's another video of the noise Promaster noise video 2

 

[phil]

just an fyi
just an opinion - you don't want any standing water on your engine

 

[laid_back_luke]

just an fyi
just an opinion - you don't want any standing water on your engine
View attachment 91620

I agree, we just got a big snow storm so it was dripping in when I had the hood open.

 

[Kip-on-truckin]

What I hear in that video is not pentastar tick. What I hear sounds kinda like flexplate, or kinda like a pcv valve. In short - there's an access panel at the bottom of the trans. Pop it, work the crank with a 27mm or crescent wrench and observe how tight the flexplate is to the crank. Should be zero slop. If that ain't it, test the pcv valve by pulling the hose on the valve cover, and plugging the valve cover side with your finger. If noise goes away, you've found your fix.

 

[laid_back_luke]

What I hear in that video is not pentastar tick. What I hear sounds kinda like flexplate, or kinda like a pcv valve. In short - there's an access panel at the bottom of the trans. Pop it, work the crank with a 27mm or crescent wrench and observe how tight the flexplate is to the crank. Should be zero slop. If that ain't it, test the pcv valve by pulling the hose on the valve cover, and plugging the valve cover side with your finger. If noise goes away, you've found your fix.

I popped the inspection cover and did not see any cracks in the flex plate but I did not have a big enough wrench to work the crank and see if there was any play. I pulled the hose on the valve cover and plugged it to test the PCV valve and saw no change.

Here is an updated video

 

[Motor7]

Almost sounds to me like something on the fan belt....pulley bearing or tensioner???

 

[laid_back_luke]

I changed the oil yesterday and added a quart of Lucas oil stabilizer to see if that would quiet anything down internally but no change. The oil looked good and I ripped open the filter to check for any debris but it was clean as a whistle.

@Kip-on-truckin few questions:
1. Is it possible the cats are so shot that it's causing a severe pressure back up? Is there any way to test this? could I remove the bank 1 cat and start the vehicle and listen or would that just throw everything off?
2. At some point I am going to have to accept it could be a lifter issue. When that time comes, any recommendations on how to properly diagnose which bank it's on. I am thinking a stethoscope would help. Are there any particular ones that tend to be the culprits due to their location?

 

[Kip-on-truckin]

I changed the oil yesterday and added a quart of Lucas oil stabilizer to see if that would quiet anything down internally but no change. The oil looked good and I ripped open the filter to check for any debris but it was clean as a whistle.

@Kip-on-truckin few questions:
1. Is it possible the cats are so shot that it's causing a severe pressure back up? Is there any way to test this? could I remove the bank 1 cat and start the vehicle and listen or would that just throw everything off?
2. At some point I am going to have to accept it could be a lifter issue. When that time comes, any recommendations on how to properly diagnose which bank it's on. I am thinking a stethoscope would help. Are there any particular ones that tend to be the culprits due to their location?

You can pretty much rule out cats - they arent going to make sound, at least not a sound like that.
You can improvise a stethescope with a piece of rubber hose, or a very long screwdriver or some such.
At this point, I would pop the belt off, start it, and see if the noise changes. Only run it for less than a minute. That test rules out everything on the beltpath.