A lot more engine noise-manifold bolts?

[IRSmart]

2018 Power Wagon, 53k miles on truck, 13k on the engine. I took a weekend trip from Baltimore, MD to Uwharrie, NC this weekend and towed a small travel trailer (~4K lbs). Typically my truck really struggles to tow anything of any real weight because of how it’s built, it’s not built for towing. Thuren 1.5” springs, King 2.5 shocks, and 37’s aren’t exactly the best towing combination.

Here’s where my concern lies. I started hearing much higher than usual engine sounds halfway down to NC. Now, that’s a hard thing to notice, because I have a muffler and resonator delete. So for me to be able to hear engine noise from the engine bay is a statement. I hear it mostly at RPMs starting around 4K and up, and it is very loud near redline. I checked the oil, oil seems fine. Exhaust fittings that I could get to seem tight.

What else could cause a sudden drastic increase in engine noise audible from the cabin? Usually my space shuttle launching sounds are restricted to the rear of the truck. Now I hear a lot from the front. It’ll be hard for a mechanic to believe me since it’s loud as ****, but when you know how your vehicle is supposed to sound, it’s easy to spot when it’s malfunctioning. Could a loose connection at the manifolds be the cause? Or broken manifold bolts? I had an engine replacement a year ago, don’t know if it’s related but I thought I should point it out. I have a lifetime warranty, just let them deal with it?

 

[Halligan]

Hopefully it's not the dreaded lifter failure.

 

[IRSmart]

Hopefully it's not the dreaded lifter failure.

How does that problem manifest itself? Figures I went 40k on an engine and blew it up being careless and the replacement engine would have the troubles lol

 

[mtofell]

Exhaust should be worse when cold. I first noticed my manifold bolts at cold start ups and took it to the dealer and they did both sides (under warranty, thankfully). Honestly, yours almost sounds like something more internal but I hope not.... or, if it's warranty covered maybe it's a good thing as you'll some new parts!

 

[RAZ175]

You didn't say what kind of noise you were hearing (exhaust leak, tapping, knocking, etc.). If the cooling fan clutch has gone bad it will cause a lot of underhood noise. Especially at higher RPM's.

 

[IRSmart]

You didn't say what kind of noise you were hearing (exhaust leak, tapping, knocking, etc.). If the cooling fan clutch has gone bad it will cause a lot of underhood noise. Especially at higher RPM's.

It’s hard to explain. It’s not a knocking, tapping, or anything like that. It’s just...louder. Much louder. I don’t know how else to explain it really. The normal growl and roar of the engine is much more pronounced than it ever was before. It’s like some of the exhaust tip noise has been relocated to coming from the firewall instead. And now that you mention it, I do hear a lot more of an air movement sound, kind of like the sound that a Toyota V6 like out of a 4Runner or Tacoma sounds, if that part even makes any sense. Grabbing a video won’t do any good, because the issue is with the VOLUME of the sound, not in any different or new sounds I’m hearing. Not sure if that helps.

 

[BWL]

Sounds like an exhaust leak. Maybe around the y-pipe.

 

[IRSmart]

I just went out and checked things as best I’m able. None of the exhaust fittings near the engine seem loose or are showing any black marks indicative of a leak. They also don’t rock back and forth at all like they’re loose. I can’t really get up in there to check the manifold bolts. The radiator fan seems normal, it’s not loose or anything. I didn’t start the truck to troubleshoot it. The oil dipstick didn’t show any signs of metal flakes in it, but I only did a close visual inspection and nothing with any magnets.

I have an appointment to drop it off tomorrow, but now I’m beginning to think I MIGHT be crazy...

 

[RAZ175]

Sounds exactly like when a fan clutch goes bad. It will be locked all the time which means the fan is turning all the time and will create a lot of noise. To troubleshoot, you have to get everything up to temp to see if the clutch is disengaging. Good luck at the dealer. Let us know what they find.

 

[IRSmart]

Sounds exactly like when a fan clutch goes bad. It will be locked all the time which means the fan is turning all the time and will create a lot of noise. To troubleshoot, you have to get everything up to temp to see if the clutch is disengaging. Good luck at the dealer. Let us know what they find.

Sounds like a good place to start. The next place I’ll be driving it is to the dealership which is 45 minutes away. I’ll check it when I get there. So in theory, at temp, and if the AC is set to off, the fan should disengage, correct?

 

[RAZ175]

Sounds like a good place to start. The next place I’ll be driving it is to the dealership which is 45 minutes away. I’ll check it when I get there. So in theory, at temp, and if the AC is set to off, the fan should disengage, correct?

Here's a good article on how the fan clutch works;
https://help.summitracing.com/app/answers/detail/a_id/5272/~/how-does-a-fan-clutch-work?

With the engine cold and off you should be able to spin the fan by hand. It will be a little stiff, but it should turn. Testing hot you need a fan blowing through the radiator and running the rpm up. You should see it disconnect.

 

[IRSmart]

Here's a good article on how the fan clutch works;
https://help.summitracing.com/app/answers/detail/a_id/5272/~/how-does-a-fan-clutch-work?

With the engine cold and off you should be able to spin the fan by hand. It will be a little stiff, but it should turn. Testing hot you need a fan blowing through the radiator and running the rpm up. You should see it disconnect.

Does the radiator fan spin cold at idle?

 

[IRSmart]

So you might be on to something @RAZ175 . I just tested the fan to the best of my ability. I could find no condition where the fan would turn off. It’s been sitting for about 5 hours, and the temp guage showed all the way cold when I went out. The fan was on at cold start, and it was also on at warm idle. It would not turn off at all. I made sure that the AC was off. I was also able to turn the fan more than 5 times in its operating direction with no increase in resistance (although i have the cuts on my fingers to show how sharp the fan blades are). I performed that test at operating temps with the engine off of that matters. I do not have a box fan handy to throw in the grille to finalize the testing, but driving tonight it now definitely sounds like a fan over-spinning. Thanks for the tip, this may help get the tech pointed in the right direction.

 

[Dodge 1500 4X4]

You have duel alternators, Is one of them making noise, you describe the noise as moving air it does sound like your fan clutch is going north on a south bound train.

 

[IRSmart]

Ok I think we’re getting somewhere. I went out this morning, truck hasn’t moved from last night. I can still move the fan as much as I want. And I noticed this morning (I didn’t in the dark last night) that this ring is just floating on the arm (or whatever it’s called) that holds the fan on. It looks like some kind of retaining grommet.

 

[IRSmart]

I should clarify. When I say I can move the fan, what I mean is that it has constant pressure on it. I can only move it 1/5 rotation at a time. It doesn’t just free spin. Does this sound like the fan is stuck in the engaged position?

 

[RAZ175]

I should clarify. When I say I can move the fan, what I mean is that it has constant pressure on it. I can only move it 1/5 rotation at a time. It doesn’t just free spin. Does this sound like the fan is stuck in the engaged position?

It does sound nearly frozen. it should move smoothly with a little resistance when its cold. It looks like a seal has come loose from the back of the clutch. May have lost the clutch fluid or got dirt inside and locked it up.

 

[IRSmart]

It does sound nearly frozen. it should move smoothly with a little resistance when its cold. It looks like a seal has come loose from the back of the clutch. May have lost the clutch fluid or got dirt inside and locked it up.

Definitely isn’t moving smoothly. I posted a video of its movement on the Wagon Facebook page. It takes a lot of effort to move it when the engine is off. I agree, I think the culprit has been found. I dropped it off today and we’ll see what they say.

 

[crazy jerry]

locked fan clutch sounds like jet engine as its moving so much air. hard to mistake it for anything else. certainly it sounds nothing like a exhaust leak imo.
use flash light and mirror or one of them snake cameras to check for blowby at manifold gasket.

 

[IRSmart]

locked fan clutch sounds like jet engine as its moving so much air. hard to mistake it for anything else. certainly it sounds nothing like a exhaust leak imo.
use flash light and mirror or one of them snake cameras to check for blowby at manifold gasket.

A jet engine is actually a pretty accurate description of what it sounded like. It’s moving a ton of air at high RPMs. A seized fan clutch I think is the culprit.