Strange noise from engine..."Whirling" sound

[SJ-Chris]

This is for a 2015 Thor Majestic 28a Class C RV with a Ford e450 V10 engine. It is a previous rental. I've owned it for about 30,000 miles and it now has 140,000 miles on it. Back in Feb 2021 I had an RV mechanic go through for a yearly maintenance check (tires, brakes, fluids, belts, radiator, etc). It was in great shape and the only recommendation was to replace the Transmission fluid (which I had them do). That was 2000 miles ago and it has been running great.

In May of 2020 (10,000 miles ago) it developed a leaking manifold. I brought it to one of my RV shops and they pulled the engine, replaced the manifold, and while they were doing that they also replaced all sorts of stuff since it was easy while they had the engine out. (Side note: It might be questionable that they had to pull the engine, but 5 of the 10 manifold bolts were snapped and they said it was the only way they could get them all out and replaced.) For the last ~10,000 miles since then it has purred like a kitten and driven well.

The RV recently came back from a 1000 mile trip with no issues I'm aware of. After the RV sat for several hours (presumably cooled down) I went to drive it 3/4 of a mile away to where I store it. When I started it up, I could immediately hear that something in the engine didn't sound right. It sounded a little bit like a leaking manifold, except it wasn't the deep rumbling sound of a leaking manifold. It was more of a higher pitched whirling sound. Maybe a rubbing sound? As I accelerate, the whirling engine noise gets louder.

Here is a youtube video so you can see/hear the sound.
https://youtu.be/MSFO99BWk1c

In the video, about two thirds of the way through I slow down and then accelerate into a right turn (that’s where you can hear the noise the best). Note: The yellow light on the left side of the dash is the Tow/Haul indicator (not a warning light).

I have an OBD reader on the RV and it tells me that ALL SYSTEMs are okay and no error codes. All of the following say “No Problems Detected”:

- Power Steering System
- Engine Management System
- Brake System
- Internal Control System
- Idle Control System
- Generator System
- Engine System
- Intake System
- Electrical System
- Turbocharger System
- Fuel System
- Cooling System
- Ignition System
- Emission System
- Fluids System
- CAN System
- Transmission System
- MIL Control System

I do not live in cold temperatures...all of this is happening with outside ambient temperature around 70 degrees F.

Here is likely a clue that hopefully will help you (help me) pinpoint what the problem could be… The engine makes this noise ONLY FOR ABOUT THE FIRST 3 BLOCKS of driving when cold. Then the noise seems like it completely disappears and the engine sounds perfect. I’ve let it cool down and then driven it 3 times this week and each time it made this initial high pitched whirling noise for about the first 3 blocks of driving and then it went away. Tonight when this happened again (noise went away after 3 blocks), I pulled over and turned off the engine and let it sit for a couple minutes. When I started it up again it sounded fine and didn’t make the noise for the rest of the short trip to put the RV back in storage.

I checked the radiator fluid, power steering fluid, and oil and they all look perfect. I didn’t check the transmission fluid.
I don’t think the engine is “Warming Up” in just 2-3 blocks so it might not be “correcting” itself via some heat related thing. But I can’t help but think maybe there is some sort of fluid/oil/etc that settles when the RV sits for a few hours and then when starting from a cold engine/start after just a few blocks things become lubricated once again (due to the engine movement/cycling or fluid pumping) and then the whirling/rubbing noise goes away.

Any thoughts what this can be??? Where should I start my investigation?

Thanks in advance!
Chris

[Grit_dog]

All I can say, is wow, $8k would get you a whole new engine, installed.
I cant even fathom how they could justify that for replacing a manifold.

[SJ-Chris]

Update....

Regarding the pin looking item...My mechanic tells me that's just part of the tension assembly and it should not be pulled.

Regarding the noise, it was diagnosed as a leaking exhaust manifold (one bolt had broken off). It makes sense that once things warm up and expand the noise goes away. I've heard exhaust manifold leaks before (when more bolts have broken off) and it was a much louder rumbling sound compared to this. Always learning...

The "good news" is that this RV had the manifold replaced 10k miles ago (~$8k repair bill) and it is still under warranty, so the shop is going to fix it.

Thanks for all the suggestions/etc.

Happy Camping!
Chris

[3_tons]

Clutch fan stuck

[noteven]

If there is a something in the tensioner assy that needs to be removed before flight the instructions that came with the assy would likely say that. They would not want a metal piece to come out and take a trip through the accessory drive systems when the engine is running at 4000rpm.

[Grit_dog]

Yes never seen a removable pin in many different tensioner pulleys.
Is the belt tight?
Good call. If 150k, it’s about time.

Couldn’t hear the noise in the video. But if it persists, could be fan clutch as well.
Good luck.

[fourthclassC]

Agree with 2112's post. End of tension spring. Do not remove is my recommendation. Why do you want to remove it. (i'm pretty sure it does not work like a timing belt tensioner where in that case, your remove the pin to allow the plunger to come out.)

[2112]

I believe what you are calling a pin is actually the end of the tensioning spring. It's not intended to be removed.

[SJ-Chris]

OkieGene wrote:
I'm not trying to be a smartass, but you might consider investing in a Shop Manual for that year engine.

Also check Youtube, there are tons and tons of videos to fix just about anything.

Best wishes to you.
.

I google and youtube like crazy!

I have searched dozens of youtube videos on this subject. Plenty that show how to replace all sorts of tension pulley assemblies but not one that shows how to remove this pin. I have it installed....I just can't get this pin out. It seems like there is lots of tension on the belt even with this pin in, but I can see that it looks like it wants to be removed and that might allow the pulley to tighten an additional 1/4 inch on the belt.

I put a socket wrench (for leverage) onto the pulley to release the tension to get the belt on. I even tried releasing the tension this way and remove the pin....but the pin just doesn't seem like it wants to budge.

Anyone have any thoughts?

Thanks!
Chris

[OkieGene]

I'm not trying to be a smartass, but you might consider investing in a Shop Manual for that year engine.

Also check Youtube, there are tons and tons of videos to fix just about anything.

Best wishes to you.
.

[SJ-Chris]

Okay....I'm replacing the idler pulley and the tension pulley and assembly.

When I got out the idler and gave it a spin, it spun more freely than the new one....about 2-3 times longer if in spin it. Apparently, when these go bad they spin longer (you want there to be some resistance). So the Idler pulley is not horrible, but I replaced it anyways.

When I got out the tension pulley and assembly I gave the pulley a spin. It spins and spins and spins for a long time. This is a sign that it is bad.

So now I've got the new pulleys in. The new tension assembly has a different type of pin (tensioner pin??). See photo:


Can anyone tell me HOW TO REMOVE THIS PIN AND WHEN? I've got the new pulleys all installed but the pin is still in. Hopefully one of you can tell me how to get it out! 🙂

Question: I'm assuming you install the tension pulley assembly and get the serpentine belt back on and in place AND THEN you remove the tension pin, RIGHT?? But how?

Thanks!!
Chris

[Terryallan]

noteven wrote:
Ford power steering pumps make a particular "whirring" noise sometimes. Cold start at -20 below, or the pump is ready for overhaul.

If it is possible have a Ford experienced person listen to it or remove the belt with the engine cold and start it and see if the noise is present.

I could be wrong.. but I think the new Fords have electronic steering.. I don't think they have power steering pumps any more. My 2013 doesn't seem to have one. At least there is no dip stick for one.

[SJ-Chris]

SJ-Chris wrote:

30sweeds wrote:
One of the belt idler or tensioner pulleys going bad.If that is the case,it's cheap and easy enough to fix but complete failure will leave you stranded.

When these start to fail (idler or tensioner), does it make sense that the sound happens from a cold start and goes away in 2-3 minutes? Maybe the bearings are starting to go and once they start rotating via the belt they quickly heat up and it makes the whirling sound go away????

I was just chatting with my neighbor who is MUCH more mechanically inclined than I am. I told him my issue. He immediately thought (before I even said it) it could very likely be the idler pulley or tension pulley. He said that when they get old or start to fail, sometimes the bearing grease starts getting hard (when the engine cools). Then, from a cold start there is momentarily rubbing that takes place (...like for a couple minutes) and eventually they heat up and it melts the grease and then the whirling sound goes away. Sounds VERY consistent with my symptoms.

I watched some youtube videos and it seems easy enough to change the idler pulley and tension pulley so I'm going to try to do that now and see if that fixes the problem. I'll let you know what happens.

-Chris

[SJ-Chris]

30sweeds wrote:
One of the belt idler or tensioner pulleys going bad.If that is the case,it's cheap and easy enough to fix but complete failure will leave you stranded.

When these start to fail (idler or tensioner), does it make sense that the sound happens from a cold start and goes away in 2-3 minutes? Maybe the bearings are starting to go and once they start rotating via the belt they quickly heat up and it makes the whirling sound go away????

[SJ-Chris]

Update: I checked on it again this morning after it had sat all night. Outside temps are ~70 degrees. The engine starts right up, but it initially does still have the "whirling" noise. It's not a squeaky belt, but a whirling noise (you can year it in the video). It sounds like it is coming from the area around the alternator, but it's hard to tell and there are lots of pulleys and the belt/fan in that area also.

When I started it up I looked at the alternator voltage via a cigarette lighter charger/adapter that has the voltage display. Before I did anything (before starting the engine), the voltage read 12.6v (healthy). When I started the engine, within 2-3 seconds the display read 14.2v (which all appears normal).

When I start the engine, I can hear the whirling noise. It gets louder as I rev the engine.

Possible clue: I didn't drive it at all...just let it idle with occasional reving. After about 2 minutes the whirling noise was gone (even if I rev the engine). Then the engine sounds fine. So whatever is causing the noise is somehow getting fixed/corrected/lubricated/etc after just about 2 minutes of the engine running. Running the engine for just 2-3 minutes doesn't seem like long enough for it to physically warm up, so it seems more like a lubrication issue perhaps. If I turn it off and let it sit for a couple minutes and restart the engine it sounds fine.

I'm not sure how bearings work (ie. in pulleys). I assume they are greased. Do they wear out and then make a rubbing/whirling noise?

I don't smell any smoke or burning of any kind (doesn't seem like the alternator is overheating).

I believe the chassis battery is only about 2 years old and is healthy.

Thoughts??
Chris