A Sooty Intake (repost from old forum) ...

[Rawze]

There has been recent arguments against the possibility of soot getting into Air Compressors from the Intake, because some MORON mechanics think that just because the EGR is PAST the air compressor circuit, that it is not possible. I guess the ignorant fools think that positive pressure from the turbo would prevent such things,.. but it is a clear lack of understanding on how charge air systems actually work. Because of this, I thought I would share this again,....

I have seen some engines so bad, that I have seen black soot puff out of the Air cleaners backwards through the engine during "turbo coughing" when the engine is shut down. i have also seen CAC Units soot-packed before because of problems like this. -- it is actually NOT THAT UNUSUAL to get soot into the air supply systems on these trucks...


- This is the result of a failing EGR Valve, creating excess turbo lag... The EGR valve was stuck wide open, and it wasn't even throwing any codes. The guys turbo eventually failed, and we decided to check out the whole system and found this. There is no telling how long this was going on inside his motor, or how much excess wear and soot is not embedded into the air system and air tanks. The the entire air system has signs of soot running through because it was so bad. --- Here is a pic,... You can tell it was happening for a while.



The Ceremic in his DPF was completely melted as well,... Here is a chunk that fell out of the back side when we took it off to inspect it. These things are made of ceremac, so how hot do you think it had to be before it melted it? --- Sad indeed!



He had just left a dealership in Virginia and brought it over here because of power loss issues. They told him his DPF was fine, and that it was normal to have turbo lag --- No codes in the Computer = a good truck,... That is what they told him!

We got him all sorted out hopefully, and maybe his fuel mileage will go up as well.

- I thought I would share these pics for others to see... Rawze

[Hammerhead]

This is largely because "Technical Schools" are now creating these fancy Technicians. Nobody wants to be a lowly mechanic anymore.
If you want to be a technician, fine, go be a technition and work on computers. What really needs to be taught is that the ECM controls a mechanical device, and that the computer can't tell you everything. Unfortunately the big engine manufacturers trying to control costs on warranty claims create the infamous Troubleshooting Tree that the Techintion must follow, or they won't pay the claim stating that the service wasn't followed according to procedure. They have become so indoctrinated by these procedures, that even when it's not warranty and we are paying the bill they can't seem to break out of the blinders and actually find the Root Cause and fix it properly.
There doesn't seem to be any desire to continue on after the Techintion has solved the software or sensor issue and become a Mechanic to investigate the hardware to find the Root Cause and actually solve the problem.
Perhaps it's time to coin a new title, Mechanical Technition. An individual that solves the whole problem, not just a glorified computer repairman.

Those pics above are horrible, and the shop that worked on that truck and deemed it Fixed should be ashamed!

[Waterloo]

So true, as that is exactly what I have seen at my local dealer. Except they know little of the computer side, and how it affects all of the systems on the truck which just frustrates them. I was speaking to the mechanic that rebuilt my motor in regards to the training they get from the manufacturers. He stated it is not enough, very vague and like you stated, it has to be by the book. These new systems and lack of proper support from the manufacturers has these guys pulling their hair out. I know these guys pretty well, and they do care about the work they do, but I can see the frustration.

[Isx Lover]

I replaced my air dryer and for shits and giggles I pulled it a part and it was full of soot! A year later I had a valve go bad on rear of truck so after I replaced it I took the old one apart, yep full of soot. Guess what the rest of the air system must look like. This is a 871 but I'm sure all egr engine's are the same.

[in2trux]

Can someone tell me why the compressor inlet isn't on the fresh air side of the turbo?
I didn't think the compressor needed to be turbocharged too.

[Rawze]

(08-31-2016 )in2trux Wrote:  Can someone tell me why the compressor inlet isn't on the fresh air side of the turbo?
I didn't think the compressor needed to be turbocharged too.

The air compressor inlet does not need positive pressure on its intake piping, but if it were routed to the intake side of the turbo, there would be a strong vacuum on it. That could potentially cause problems with the air compressor head, and put the engine at risk for runaway (or coolant intrusion) if it failed.

[Kevin7898]

(08-31-2016 )Rawze Wrote:  

(08-31-2016 )in2trux Wrote:  Can someone tell me why the compressor inlet isn't on the fresh air side of the turbo?
I didn't think the compressor needed to be turbocharged too.

The air compressor inlet does not need positive pressure on its intake piping, but if it were routed to the intake side of the turbo, there would be a strong vacuum on it. That could potentially cause problems with the air compressor head, and put the engine at risk for runaway (or coolant intrusion) if it failed.

so theoretically someone could put a filter on the compressor line and plug the hole to the intake?

[Unilevers]

(09-21-2016 )Kevin7898 Wrote:  

(08-31-2016 )Rawze Wrote:  

(08-31-2016 )in2trux Wrote:  Can someone tell me why the compressor inlet isn't on the fresh air side of the turbo?
I didn't think the compressor needed to be turbocharged too.

The air compressor inlet does not need positive pressure on its intake piping, but if it were routed to the intake side of the turbo, there would be a strong vacuum on it. That could potentially cause problems with the air compressor head, and put the engine at risk for runaway (or coolant intrusion) if it failed.

so theoretically someone could put a filter on the compressor line and plug the hole to the intake?

yup works fine

[Rawze]

(09-21-2016 )Kevin7898 Wrote:  so theoretically someone could put a filter on the compressor line and plug the hole to the intake?

I have seen people do this before. It works great, but gives you no advantage in fuel savings. It only serves to reduce the chances of soot getting into it.