deuce exhaust sound...HELP!

[G-Force]

Cougar,
That sounds more like a head gasket on that truck.
While USMarine sounds more like a compression release/jake brake sound.
Maybe your valves are adjusted too tight on one cylinder. Have you done any work on the top end recently???

 

[randyscycle]

How about an injector stuck open? That would account for the white smoke (unburned fuel) and clearing up over idle somewhat as the engine can process the major amount of fuel in that cylinder enough to smooth out a bit.

Just a thought.

 

[stumps]

My initial thought based on the puff puff puff... sound of the truck doing the recovery training was it sounded like a car I once had where I had to remove the spark plug so I could limp home after a head gasket blew and was hydro locking one cylinder. The puff puff puff sound of the air woofing out of the spark plug hole was amazingly loud.

A head gasket is probably the right answer. Given that the drivers keep barreling into the deep water over and over and over again, odds are pretty good that they slurped up a bunch of water on one of the trials, and hydro locked one cylinder, blowing out a chunk of the head gasket. That would definitely give the characteristic puff-puff-puff sound that it gets at idle.
I just wouldn't have thought it would be that loud. But maybe on a diesel it would.

It certainly would account for the white exhaust. The damaged cylinder would be puffing out raw diesel vapor every exhaust stroke. There ought to have been a lot of raw diesel fumes around the engine, too, if that is where the engine was blowing.

As to USMarine's engine, I am suspicious of a bent pushrod that is preventing the intake valve, on one cylinder, from opening at all. That would account for the missing beat noticable at low speeds, but it should also result in oil thinning from the diesel being injected into the cylinder with no other place to go.

-Chuck

 

[usmarines72]

Most everyone I have spoken to seem to think it may be a plugged or wide open injector. How would one go about diagnosing this? Pull each injector off individual and let fuel pass through out of the engine? I know this is probably less than desirable b/c of the huge PSI's coming out. Maybe backing off the injector mounting bolts one by one to see which one impacts the RPM's dramtically? Or maybe ordering one like new or new injector and just replacing each one down the line to see which one causes all the exhaust sounds to go away? I have never gone into the engine and I am not intimidated by the engine to do so. Just need a good starting point to go off of. Any good sources on a good take out injector or two?

 

[ALFA2]

Usmarines72, you can somewhat easily check to see which injector is not working right, by running the engine, just to the rpm below when the sound begins, open the hood and carefully, before it gets too hot, touch each of the injector lines going to the injector 2-3'' from the injector, and you will feel/hear a certain pulse/ sound from them, as the engine stays at the given rpm. Then have someone lean on the fender that causes the noise to be made, and get the rpm to where it does make the noise, and you check the injector lines again, just like before, also looking for any unusual vibrations or sounds that come from the injector, you will know which one it is, as it will feel very different to you hand. That is a cheap and reasonably accurate way to spot a problem injector/line, without use of any tools or equipment. Once you locate the one with the problem, if it is an injector, then you will have to try to find the cause if the problem.
Depending on if it is the line or the actual injector, an injector may have to come out.

I hope this helps some.

ALFA2

 

[stumps]

No need to remove the injector, just idle the engine, then one at a time, loosen the fitting nut (at the injector) on the steel tube that comes from the IP. Loosening the nut will cause the IP charge for that cylinder to leak out rather than power the injector. If the cylinder is doing work, the idle will roughen, and the sound will change. If the cylinder is dead, you will hear no change. (Do I really need to say that you must keep your fingers away from the fitting nuts, while you are loosening, or tightening them, while the engine is running?)

ALFA2's idea about feeling the IP line for each injector is very useful tip! You should be able to feel a difference, if the injector is plugged. You might not feel any difference if the injector's orifice is blown open too wide.

Another trick is to measure the temperature of the exhaust manifold port for each cylinder with an IR thermometer gun. The dead cylinder's port will be ice cold, the others will be warm at idle.

-Chuck

 

[OPCOM]

The poppong sound is not normal.

There are also very minor incantations of this sound type. There can be a slight but ignor-able imbalance in the running of the engine at no load where very little fuel is used. It can make the engine run very slightly un-smooth. A fix could be injector replacement or maybe even pump replacement, or a valve adjustment as mentioned etc. It never hurs to check everything.

If nothing can be found and if it is very minor, has no effect on smoothness under power, and cracking the injector lines always makes a very big difference, that's a normal variation for some trucks. It is not a caddilac and will not idle like one.

 

[OPCOM]

Low IP pressure can also cause this problem. An easy way to check pressure is to just turn up pressure while at idle and see if miss goes away. Low pressure will cause fuel to glob in instead of mist.

I'm familiar with turning up the fuel rate, but how do you turn up the pressure?

 

[usmarines72]

Wow thank you gentlemen for these outstanding tips. Probably will be about a week before I can work on her. Will advise my findings

 

[dittle]

Judging by the number of times that truck has been dunked hot into cold water, I would bet on an exhaust manifold with a big crack in it next to one cylinder's exhaust port.

-Chuck

There is another video of that same truck before it had the funny sounds coming out of the engine. The driver hit the water at near red line, sucked water in through the air intake (via the massive wave he created) and killed the truck via hydrolock at that speed. There is more wrong with that engine than just a head gasket or leaking exhaust manifold.

 

[stumps]

There is another video of that same truck before it had the funny sounds coming out of the engine. The driver hit the water at near red line, sucked water in through the air intake (via the massive wave he created) and killed the truck via hydrolock at that speed. There is more wrong with that engine than just a head gasket or leaking exhaust manifold.

If the cylinder had only a small amount of water in it, it would lock at almost all the way to TDC. That is the point where the crank has maximal mechanical advantage for playing punch press. It could easily blow the gasket out, and still remain ok otherwise. Until it is cracked open, it is only a guess, though.

-Chuck

 

[Wildchild467]

Another trick is to measure the temperature of the exhaust manifold port for each cylinder with an IR thermometer gun. The dead cylinder's port will be ice cold, the others will be warm at idle.

-Chuck

What exhaust temperatures are you guys getting at the exhaust manifold just off the cylinder head at idle? i think i have some injectors that are dirty or something. i checked my temperatures and they vary 70 degrees or so. one was 220 and another one was about 300. im going to change my filters tonight, (spin ons) and see what happens. this has been a persistant issue for me and i dont think its all in my head.

 

[treeguy]

Can anyone elaborate on the cracked manifold idea? It would make sence that a hot part like the exhaust manifold would crack if you drove a hot truck into water, so..... how does anyone snorkle their trucks/jeeps/toyotas ect. and run the deuce under water like a mil. video I've seen with extended pipes and the driver wearing scuba. What is the depth rating for fording kits, couldn't be anywhere near a manifold right?

Not trying to ruin this thread, you guys have some great info here. This issue Stumps mentioned caught my eye.

 

[stumps]

Fording deep really isn't something you should do with a deuce on a regular basis. It isn't a submarine, but if you really needed to do it, the thought of braking an exhaust manifold probably isn't going to stop you. If I really had to take a deuce swimming deep, and with the kit, the water can go above the roof of the cab, I would cool the engine down (if I had the opportunity) and I would enter the water slowly. It can't be all that good for the fan to hit the water with the engine roaring.

After such a ford, you would have to PM everything on the truck.

-Chuck

 

[Wildchild467]

i think you have to loosen the fan belt up so it slips to allow it to ford. might as well spray degreaser on the engine before you ford it into water!

 

[deathrowdave]

My 2 cents worth the injectors need to be cleaned and pop tested for the correct opening pressure . Sounds like one is opening way to low pressure .

 

[Woodsplinter]

Was this problem ever solved? Inquiring minds want to know!