ran my hemi hard today, she did NOT like it

[silver billet]

I'm kinda worried about the ole girl. I was getting onto the freeway and there was a short onramp and lots of traffic so I leaned into it pretty hard and fast. It revved up and downshifted as normal, but it really made a loud crackling noise for a few seconds while it was at 3000 to 5000 rpms (also I think it might have lost a bit of power while it was crackling away); went away the instant I got off the throttle and it upshifted. Back to smooth hemi sound.

Later in the trip I gave it a bit a few times, but not as hard, and sound didn't come back? Sounded like a well running hemi should.

No codes anywhere on the dash, but I will swear that was NOT normal. It sounded like I lost my exhaust for a few seconds?? But the sound was definitely "out front" under the hood, it was not a sound coming from behind. Freaked me out, never heard that before.

Anybody have any ideas?

 

[Zeronet]

Knock or pinging? What octane fuel are you using and what brand?

 

[Nails]

Pinging, would say not abnormal/ not normal either.

 

[silver billet]

I'm pretty sure it wasn't knocking or pinging. I was running ethanol free 91 octane for at least 5-6 tanks straight now. I also know what that sounds like.

This sounded closer to the crackle you hear when people mod their exhaust, or when the SRT Jeep opens wide up, almost like a snapping type of crackle, but my sound was not nearly as smooth sounding. It honestly sounded like an exhaust issue in the engine bay, but have no idea why it would do that only under WOT briefly.

I dread this kind of sh_t, because I already know the dealer won't replicate it and will look at me crosseyed. But I know what I heard, and it wasn't normal. It's probably going to come back to haunt me right when my warranty expires.

Worst part about it, in order to replicate, I have to beat on it. And I hate doing that. I'm not one to do that very often.

 

[TheMadDutchDude]

It’s a HEMI. Beat on it a little.

 

[SD Rebel]

The only way to be sure is to try and replicate it again within reason. I will say, I see these drivetrains abused far more then you mentioned on a rather regular basis without issue.

If there is an issue, you want to expose it now so it can be fixed under warranty. My worry is it's some sort of small exhaust leak or driveline issue that only exposes itself under strain and if you baby it, it won't expose itself further until after warranty.

 

[TheMadDutchDude]

What he said. I beat on mine every so often and haven’t had any issues yet. How can you not punch it and hear that beast roar? Best sounding motor out there.

 

[J-Cooz]

I wouldn't worry, I pound the **** out of mine.

 

[KcRay]

Hopefully it was just a weird little hiccup. I would not be afraid of it happening again, because if its going to happen again, better it does it sooner than later. If someone is wrong you did not do it, you just found it. "Use that pedal on the right"

 

[Richard320]

Do you normally drive sedately and a lot pf short trips? It could have been a bunch of accumulated carbon buildup breaking up. Sounds like someone threw a handful of gravel down the intake and you're hearing the engine chew it up?

 

[SpeedyV]

I'm pretty sure it wasn't knocking or pinging. I was running ethanol free 91 octane for at least 5-6 tanks straight now. I also know what that sounds like.

This sounded closer to the crackle you hear when people mod their exhaust, or when the SRT Jeep opens wide up, almost like a snapping type of crackle, but my sound was not nearly as smooth sounding. It honestly sounded like an exhaust issue in the engine bay, but have no idea why it would do that only under WOT briefly.

I dread this kind of sh_t, because I already know the dealer won't replicate it and will look at me crosseyed. But I know what I heard, and it wasn't normal. It's probably going to come back to haunt me right when my warranty expires.

Worst part about it, in order to replicate, I have to beat on it. And I hate doing that. I'm not one to do that very often.

Hmm...maybe a cracked exhaust manifold or leaky gasket? Something that would tighten up once hot?

 

[MannymanX]

I drive my truck pretty hard and never had anything of that nature... If you never gun it and this the first time in a long time, it could be some carbon buildup.
You should have more fun with it... IT'S A HEMI!

 

[Stevenc150]

...I dread this kind of sh_t, because I already know the dealer won't replicate it and will look at me crosseyed. But I know what I heard, and it wasn't normal. It's probably going to come back to haunt me right when my warranty expires.

Worst part about it, in order to replicate, I have to beat on it. And I hate doing that. I'm not one to do that very often.

U should "beat it" to expose any problems while the warranty is still in your favor

 

[Boston]

One time only event? Unless you can replicate it I say it was another vehicle on the road.

If you want my guess, it was a tractor trailer using it's Jake brake to slow down

 

[silver billet]

Hmm...maybe a cracked exhaust manifold or leaky gasket? Something that would tighten up once hot?

I didn't want to suggest it on the account of me appearing daft, but yes this is what I thought of too. I've always thought my engine had more noise than the tester I drove weeks before I got mine. Especially going up a hill with rocks on the side where the noise is echoed back into the truck, very noticeable. Like a permanent small leak in my exhaust.

Also when it shifts going down the road, it sort of "wheezes" for a second when it slips into the next gear. Dunno if that is normal.

But if I have an exhaust manifold issue or leaky gasket, would that make sense that it shows up suddenly much worse for a few seconds under intense strain/pressure? Is there that much pressure in the exhaust that it would force a "bigger leak" under WOT just for a few seconds?

Because that would perfectly describe the sound, like a big hole in the exhaust up front for a few seconds.

 

[silver billet]

One time only event? Unless you can replicate it I say it was another vehicle on the road.

If you want my guess, it was a tractor trailer using it's Jake brake to slow down

The morning after, yeah I can never be certain. But quite sure it was my engine. The noise perfectly matched the revs in my engine, and was 100% "in sync" with me; appeared instantly under WOT, left the second I got off it. It was also "in front" of me, jake brake would sound from behind. Again hard to recall, but don't remember seeing any big trucks at that second, was just cars/small suvs and one Fiat van in particular that I was trying to get in front of.

 

[Gplattinum]

Ethanol free...? There's no reason to run that in modern day vehicles. Ethanol is what keeps things cool in the combustion chamber. I wouldn't be surprised if that crackling was back/after fire from heat build up. I would love to run e85 if it wouldn't void my warranty with a tune. To each their own, but I'd keep the e free in my mower and boat.

 

[Rsorrell2]

Why run and pay for 91 when it calls for 89?

 

[Nails]

^^^^ I don’t disagree. For my truck, climate I live in and I’ve noticed less heat soak bog(timing pulled) with higher grade fuel. So I just stay running it. If I was younger without kids,wife Ect. I would def data log this more intense to have a scientific backing of if it’s truly real or not.

 

[SD Rebel]

Why run and pay for 91 when it calls for 89?

Sounds like he wants to use ethanol free fuel, maybe 91 is the only way he can get it? As for me, I only use 91, but that's because I use Costco, and they don't have 89. But their 91 is cheaper than everyone else's 87.