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New bad noises from the 3406B!

skyking1

Senior Member
Joined
Nov 3, 2020
Messages
7,462
Location
washington
When I started home something happened and she started hammering under load. I also noted more of a blowby smell, but that could be me.
I pulled over and listened, looked around, and it just does not sound bad at idle. It does not sound bad standing next to it and free revving it at the pump either. It only sounds like this when it is making power. It sounds to me like a gasser with a cracked manifold.
Pressures and temps were normal, oil looks OK. Tomorrow I will give the coolant another look too.
Here is a video for the sound. i was in stop and go, and it only chugs when making torque.
I tried embedding it but not go. Click the link and tell me what you think it might be?
https://youtube.com/shorts/f8LZUTyNjIQ?feature=share
 

JPV

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Joined
Aug 20, 2015
Messages
756
Location
S.W. Washington
You might crack injector lines first to see if you can isolate the cylinder then look at the valve train. If it looks fine I would cut the filter too see what you see. If that looks good and there are no exhaust leaks (that's kinda what it sounds like to me in the video) I am not sure what it could be.
 

Coaldust

Senior Member
Joined
May 9, 2011
Messages
3,286
Location
North of the 60
Occupation
Cargo Tanks, ULSD, RUG, Methanol, LPG
It does sorta have an exhaust leak sound to it. Good thinking.
 

skyking1

Senior Member
Joined
Nov 3, 2020
Messages
7,462
Location
washington
thanks guys.
broken valve spring and I might have some contact, or just an ugly leak at that valve?
 

Coaldust

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Joined
May 9, 2011
Messages
3,286
Location
North of the 60
Occupation
Cargo Tanks, ULSD, RUG, Methanol, LPG
3406B down! If those wheels ain’t turning’ you ain’t earning. Put me on the job. I can fix her up.
 

terex herder

Senior Member
Joined
Nov 10, 2017
Messages
1,778
Location
Kansas
Those cat exhaust studs are the worst I have ever tried to remove. Normally, I will weld a handle on the stud and can back it out with a pair of vise grips. Every filler rod I tried, the weld would break off the stud and the end of the stud was glass hard. I then had to grind out the hard spot before I could drill the stud. I ended up making a drilling plate that would locate on non-broken studs and hold the drill bit on location to drill a pilot hole in the stud. I was then able to remove the broken stud with shop made un-easy outs.
 

Jonas302

Senior Member
Joined
Jan 4, 2015
Messages
1,197
Location
mn
Finally someone else that wont use the word easyout lol

I can't remember the 3406b truck I did being to bad but I will never forget doing a cat loader last summer out in the mosquito filled gravel pit it had those glass hard studs in it 3 days drilling the only thing that would even come close to cutting was carbide bits they would last for half a stud or so

Did a Mack last week and they all welded and unscrewed on the first try even though the break was recessed in the head quite a ways I was a happy camper!
 

kshansen

Senior Member
Joined
Mar 11, 2012
Messages
11,128
Location
Central New York, USA
Occupation
Retired Mechanic in Stone Quarry
This is what is shown in "Dealer Service Tool Catalogue":
stud tools.png

However this does not seem to show the template that I recall the dealer using when we had some broken studs on a 3408. I had managed to remove all but a couple by welding nuts to the broken parts and removing them. Dealer guy also tried that with no luck. He then had a plate/template that bolted to the head and accepted bushings to guide the special drill bits to drill out the broken studs.

I had a little better luck doing a 3306. Some studs took a few tries to weld on the nut to remove the studs but managed to get them all out.

One trick that helped on some was to place a 3/8 inch flat washer around the broken stud and weld that to the broken bit and then place a 1/2 inch nut on top of it to weld to it. I think that gave you the ability to get better penetration into the stud and also put more heat into the broken stud so when it cooled a little it would shrink a bit.
 

skyking1

Senior Member
Joined
Nov 3, 2020
Messages
7,462
Location
washington
It's one of those parts that are more about time and less about miles/hours. On the plane they would rust away. This engine only has 210,000 miles but it's 30 years old.
 

Bluox

Senior Member
Joined
Jun 19, 2010
Messages
1,960
Location
WA state
This is what is shown in "Dealer Service Tool Catalogue":
View attachment 261731

However this does not seem to show the template that I recall the dealer using when we had some broken studs on a 3408. I had managed to remove all but a couple by welding nuts to the broken parts and removing them. Dealer guy also tried that with no luck. He then had a plate/template that bolted to the head and accepted bushings to guide the special drill bits to drill out the broken studs.

I had a little better luck doing a 3306. Some studs took a few tries to weld on the nut to remove the studs but managed to get them all out.

One trick that helped on some was to place a 3/8 inch flat washer around the broken stud and weld that to the broken bit and then place a 1/2 inch nut on top of it to weld to it. I think that gave you the ability to get better penetration into the stud and also put more heat into the broken stud so when it cooled a little it would shrink a bit.
Number 4 is the drill guide.
Bob
 
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