Backfiring through turbo?
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Cargo Master
Joined: Oct 2008
Posts: 2,308
Likes: 1
From: Elyria, OH
Backfiring through turbo?
04 f350 6.0 with 305k on it. I was pulling a trailer home and have been driving on the freeway when I started hearing a popping noise and black smoke from the exhaust while I'm cruising at highway speeds. Found it coming from the intake. I removed the intake to look at the turbo and didn't see anything wrong. Started the truck and had someone power brake it and it sounds to me like the trucks backfiring through the turbo. I swept the vanes on my snap on solus and found it sounds like the vanes are moving properly. Removed turbo just to check everything out and found turbo to be working properly. The truck idles fine. There are no faults. I've checked the egr, ebp, and map sensors koeo and found all reading about the same (14.6ish) map values change with boost. It almost sounds to me like the vanes are in the wrong position or something. Like being commanded closed when they should be open or what not. Anyone ever heard anything like this before?
Postmaster
Joined: Aug 2015
Posts: 3,910
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From: NW IA
I always chuckle when someone is posting something at the same time.
You did add some good additional points
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Cargo Master
Joined: Oct 2008
Posts: 2,308
Likes: 1
From: Elyria, OH
I honestly think it's an issue with the turbo. The noise I'm hearing sounds exactly like when you power brake, spool the turbo and then let off the throttle quickly.
If that makes any sense
Hotshot
Joined: Dec 2014
Posts: 17,823
Likes: 3,101
From: Jersey Shore
Synchronized responses ......
Hotshot
Joined: Dec 2014
Posts: 17,823
Likes: 3,101
From: Jersey Shore
Forgot to add that. I pulled both valve covers due to reading about those issues. I started the truck and didn't see anything abnormal. Pulled both oil rails and inspected all the rocker arms and cranked the engine with the little wire on passenger side fender. Everything was moving properly as far as I could tell.
I honestly think it's an issue with the turbo. The noise I'm hearing sounds exactly like when you power brake, spool the turbo and then let off the throttle quickly.
If that makes any sense
I honestly think it's an issue with the turbo. The noise I'm hearing sounds exactly like when you power brake, spool the turbo and then let off the throttle quickly.
If that makes any sense
I had an issue where one lifter would drain down after a long sit. I had other issues too, but .......
Anyway, this is what an exhaust lifter that is not opening all the way and letting compression blowback through the intake valve and filter sounds like. Once my lifter pumped up, it sounded OK.
Actually, if you listen very carefully during the slowed section you can hear two other cylinders acting in a minor amount. Three altogether. Light thump, light thump, big thump.
You could take a video and use the jumper on the passenger fender to the battery positive post to turn the motor over and listen for a single compression issue. Post it here.
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Laughing Gas
Joined: Aug 2004
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From: P.G. VA
BRay, Not that it will help your issue but I have experienced the exact same thing you are experiencing I believe. Driving along at a steady constant speed and I would start to hear an odd, hard to describe, noise under the hood. Each time it did it I would get a puff of black smoke out the pipe. it seems to do it mainly after stopping and turning it off for a few. I myself thought it to be a turbo "fart" but yet that makes absolutely no sense when running a constant speed. Mine however hasn't done it in a while and seems to run fine otherwise so I'm not too concerned unless it starts again. Curious to see what you determine is the exact cause.
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Cargo Master
Joined: Oct 2008
Posts: 2,308
Likes: 1
From: Elyria, OH
Im sorry for the late response. I did not get email notifications for your replies.
Anyways, I think the misfire is unrelated. Honestly thought it was injectors as it has always had a random misfire issue at red lights or cold starts abs other times it purred like a kitten.
Thus noise it's not present at idle. Only when getting on the throttle and the turbo starts building boost. I will get a video tomorrow. I also bought a compression adapter to compression test cylinder 5.
Anyways, I think the misfire is unrelated. Honestly thought it was injectors as it has always had a random misfire issue at red lights or cold starts abs other times it purred like a kitten.
Thus noise it's not present at idle. Only when getting on the throttle and the turbo starts building boost. I will get a video tomorrow. I also bought a compression adapter to compression test cylinder 5.
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Cargo Master
Joined: Oct 2008
Posts: 2,308
Likes: 1
From: Elyria, OH
I've checked MAP, EBP and BARO sensors with KOEO and they all read the same so I figured all the sensors are good. But I've had a lot of people mention this sensor. I've pulled the tube and sensor and blew them out just to make sure they were clean and they were pretty clear. I may just go get one from the dealer and throw it on and see what happens.
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Cargo Master
Joined: Oct 2008
Posts: 2,308
Likes: 1
From: Elyria, OH
Photobucket no longer supports videos. And the attachment is an mp4 which is unsupported by the attachments here. Anyone know a way around this?
On edit:
https://youtu.be/5j_4FzU9UpM
On edit:
https://youtu.be/5j_4FzU9UpM
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Cargo Master
Joined: Oct 2008
Posts: 2,308
Likes: 1
From: Elyria, OH
Koeo shows 200 inHG desired I thought the same thing. But just dont know where to look. I have my other 6.0 all torn apart and can't really compare. Even if they are different, where should I be looking?