Question on smoke output

[Rawze]

(11-11-2016 )joed2323 Wrote:  Thanks rawze.

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I did not know or have ever heard of excess boost issues with the cm2250s, that is good to know. What causes over boosting? Just faulty sensors or something within the turbo components?
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It is called terrible factory programming. Any slight imbalance or restriction in the exhaust or EGR components, especially during engine warm-up, and the ECM ramps up the turbo too high to try to compensate it.

Here is a video of one that has gotten so severe it is destroying the turbo...
https://youtu.be/huZXZnoNfrE

THIS ABSOLUTE MORON of a mechanic is so incredibly clueless it is not funny! -- and so are the people who commented on this video! -- WHAT a SHAME!@.

By the way,..the engine changed operating modes right at the very end of the video,you can hear it. It had nothing much whatsoever do do with what he was doing to it, other than the fact that it was warming up and jumped out of cold amb./ rapid warmup mode.

The engine is cold (below 140 F) it uses the turbo and over-spools it to put an internal load on the engine. It is the equivalent putting the engine under slight load to warm it up faster. This internal load also makes the engine and valve train quieter (cold diesel engines have noisy valve clatter while warming up otherwise). -- HIS PARTICULAR PROBLEM!-- Other than he is completely clueless AND USING A F$#$KING PIPE PLIERS ON A TEST PORT FITTING, Is in fact that the ECM is not seeing enough pressure at the intake manifold during warm-up. The turbo is WAAY OVER-BOOSTING, then "chuffing" (reversing direction rapidly). This is very very harmful to it. - it is most likely because the IMAP sensor (or EGR Delta-P or Exhaust manifold pressure sensor) is packed with soot and reading incorrectly.


This is one of my biggest complaints on how the turbo is programmed from the factory. They use what is known as "mass charge flow" (MCF) -- the sum of flow and pressure, and it wants always, a certain amount of it, regardless of the turbo position. this means if it is not seeing enough at the intake,.. The turbo will ramp up and choke off the exhaust, making for excess heat, flow restrictions, and a lot of other potential problems (like destroying turbochargers) to make the engine "see" with the IMAP and other sensors, what it want to.

This also means that if you have a huge crack in your charge air cooler, or have a restriction in EGR piping, leak, bad sensor, etc. - The turbo will simply ramp up higher and higher (to the point of damage if necessary) to compensate for the pressure loss,.. and your fuel mileage goes down, engine looses power, emissions system problems, etc. - And you are left scratching your head as to what is wrong. It is also why all of the bad deletes out there will cause repeating turbocharger failures, because the engine will see the blocking plates in the EGR system, or the valve closed, and try to make up for it by over-spooling the turbo out of control.