Clanking/rattling when revving or starting engine

[F-150 Prius]

Wow. I guess Fords truck are not “BUILT TOUGH” anymore huh

Well, it's a rattly heat shield. Probably a lowest-bid part from any stamping company, $2.50 part will cost $250 in a warranty service visit.

Sponsored

 

[vs1]

Hey I was just wondering if replacing the cat fixed your issue? I have a 22 powerboost and it’s making the same exact sound when the engine kicks on. Mainly does it when cold, but occasionally it’ll do it while driving slow thru a neighborhood.

I had this issue as well. My truck ran a CEL code P2C22. Got it checked by the dealer and they said it was the Exhaust Heat Exchanger that was faulty. They replaced it under warranty and the problem is fixed. The techs also told me the part number has changed on the heat exchangers which could mean that Ford remanufactured the part to prevent future faults. Hope this helps!

 

[20XLTFX421]

Going to make an appointment to have mine checked. Hopefully they will replace mine as well.

 

[EricR]

... or a careful dollop of RTV using a spudger as needed to work it into the offending rattle gap. Can be a permanent fix or just a sanity saver while waiting for parts. : )

I don't know what a SPUDGER is.

But now, thanks to you, my tool chest no longer feels compete until I have one.

 

[thebigdu]

I had a very similar noise on low speed accel and deccel. Was sure it was a loose heat shield. Finally got under the truck tonight and found a bent and mostly detached label on the top side of the resonator. This label is a very, very thin steel, and I'm fairly certain this was the cause of my rattles. Easy fix... Just rip it off!

 

[Jerome10]

Well, it's a rattly heat shield. Probably a lowest-bid part from any stamping company, $2.50 part will cost $250 in a warranty service visit.

I've got the exact same noise as both videos in this thread. Hoping it isn't the cat (truck has 3000 miles on it) and would like to start with heat shields.

Do you happen to know which heat shield was causing your problem? I crawled around with truck off and cold tapping on various things and could not locate any obvious heat shield rattle.

May end up at the dealership but if its a shield I can just bend a tad and be good, I'd prefer not to have to take it in.

FYI mine is very bad around 1700-1800 rpm when the engine is cold. It progressively gets better as the engine temp increases and for the most part is gone once at full operating temp. Maybe slightly still audible if in a parking garage and I really listen once warmed up.

Clip of my engine noise. 6 seconds in it starts around 1500 rpm by about 18 seconds it is closer to 1800rpm and extremely loud.

 

[surveyor]

I've got the exact same noise as both videos in this thread. Hoping it isn't the cat (truck has 3000 miles on it) and would like to start with heat shields.

Do you happen to know which heat shield was causing your problem? I crawled around with truck off and cold tapping on various things and could not locate any obvious heat shield rattle.

May end up at the dealership but if its a shield I can just bend a tad and be good, I'd prefer not to have to take it in.

FYI mine is very bad around 1700-1800 rpm when the engine is cold. It progressively gets better as the engine temp increases and for the most part is gone once at full operating temp. Maybe slightly still audible if in a parking garage and I really listen once warmed up.

Clip of my engine noise. 6 seconds in it starts around 1500 rpm by about 18 seconds it is closer to 1800rpm and extremely loud.

Had the same sound + symptoms (1400-1800 RPM, cold engine). Sound would go away on battery only, was most noticeable when accelerating.

Drove me bonkers.

Visited dealer 3x w/o luck. Paid independent dealer $200 to hunt it down – looking for loose clips, checking bolts, etc. Nothing. Finally did a 4th visit to a different dealer. They asked to keep it overnight so they could get a truly cold start. By end of day, they reproduced + diagnosed – heat exchanger – 2nd replacement (1 w/ previous owner before I purchased it CPO).

Week later, fixed, noise is gone. Also saw the threads about fixing the mirror rattle, and fixed that, too.

Now I don't know what to do with myself.

 

[Jerome10]

Had the same sound + symptoms (1400-1800 RPM, cold engine). Sound would go away on battery only, was most noticeable when accelerating.

Drove me bonkers.

Visited dealer 3x w/o luck. Paid independent dealer $200 to hunt it down – looking for loose clips, checking bolts, etc. Nothing. Finally did a 4th visit to a different dealer. They asked to keep it overnight so they could get a truly cold start. By end of day, they reproduced + diagnosed – heat exchanger – 2nd replacement (1 w/ previous owner before I purchased it CPO).

Week later, fixed, noise is gone. Also saw the threads about fixing the mirror rattle, and fixed that, too.

Now I don't know what to do with myself.

Appreciate the update.

I finally had the truck in at my dealership last week and they said the noise is near the wastegate and deemed it a wastegate rattle. They told me they also checked another powerboost and it made the same noise at the same RPM (I didn't have time when picking up my truck to ask them to demonstrate it for me on another truck).

I'm not sure I buy it. To me, the wastegate rattles were a very different sound. Not this metallic heat shield sound like in this thread and my video.

I was hoping they'd find a heat shield and it would be a quick repair. But at some point I'm going to have to get someone to press the throttle while cold while I poke around for the noise.

I will look into heat exchanger failure as you mentioned. I hadn't come across that yet in all my searching about this noise.

 

[surveyor]

@Jerome10 For the longest time, I also thought my noise was a loose heat shield, but neither the dealer nor a well-rated independent mechanic could find anything loose. I don't know if you have the same problem I did, but the video sounds very similar (as do your symptoms), and I've now listened to probably over 30? videos while troubleshooting this. I don't know if you have the option, but if you can visit a different dealer, I would encourage that.

I debated whether to write this because I wasn't sure it would be helpful, but since they replaced my heat exchanger (part of the muffler inlet pipe, I think), it's like a new truck. I didn't realize how much of a difference it made, esp. during acceleration. It's like I'd been accelerating into a vacuum, and now I have my responsive truck back – it's actually fun to drive again. Good luck finding the root cause and let me know if I can help, because before this was fixed, it was like a physical ailment I couldn't shake.

 

[kevphe15]

I have a 21 Powerboost, and a portion of the exhaust is being replaced due to a heat exchanger issue. It took some time working with the dealership Service Manager to diagnose, but used this thread to help point in the right direction. The clanking/rattling was occurring during cold start, and while the engine was heating up driving around 1.5-1.8 RPMs. The dealership ordered this part (under warranty) and is replacing in a few days. The SM told me that more and more service notes were showing up on the forums internally they used as well.

Hoping this part fixes the awful clanking/rattling I keep hearing for the last few weeks!

 

[Jerome10]

Thanks for the update. I have not tackled this since last posting here. Hoping now that we're in spring I won't have as cold of a garage and can more comfortably go under the truck.

To help diagnose, if I go under the truck and do some tapping, can I hear the heat exchanger rattle?

Or if I have someone start the truck while underneath, can I hold any particular part of the heat exchanger and get the rattle to stop?

Just curious how to demonstrated definitively to the dealer that it is the heat exchanger (after I am able to verify myself)

 

[Jerome10]

This is the best video I've found of the exact same noise mine is making, worst at about 1800rpm.

Unfortunately the user didn't mention a solution and I am not a reddit user and can't reply.

Anyway, great video. Right at 16 seconds it starts and is spot-on to my truck. And I still haven't tackled mine yet...

 

[Jerome10]

Well, I finally decided to get under the truck and go to town on this one. It has been nearly a week since working on it and I think I actually licked the problem. Hoping it might help some others...

I removed similar "metal" stickers from mine. I don't think this was the source of the problem but they were half coming off so I took them off. They were on the cats (?). Small/short fat tubes, both sides, just behind what I think are the turbos.

But I'm nearly certain that the rattle was, indeed, a heat shield. The large shield on the passenger side, above the cat, that extends to where the driver-side pipe joins with passenger-side pipe.

Banged around (gently) on all sorts of stuff with my hand and a rubber mallet. This heat shield really clanged and reverberated. So very gently pushed it upwards in a few spots. Not even enough that I could say I actually bent anything... but I must have moved it just enough. The sound is gone. So so so so much happier pulling from a stop now. Sounds completely normal.

Hope this helps others.

 

[Jerome10]

Issue seems to be returning. I suspect maybe its the cooler mornings in the 30s and low 40s. I wouldn't say it is as bad as it used to be before I did the heat shield adjustment. Seems to disappear after a bit of warmup. But basically every first run through the gears it seems to do it.

To those with heat exchanger defects, did the truck throw a light or anything on the dash? Or did the dealership have to do a specific scan to check for codes? Something I could read with the OBDLink MX+ I recently purchased?

I will likely have the dealer check again when it gets below freezing and that IWE grinding inevitably returns and I have them do that TSB.

 

[dochawk]

I don't know what a SPUDGER is.

Oh, dear!

So what do you do when you need to spudge?

Sponsored