Blocked EGR Passages???

[Sinister6]

I am tearing down my engine and noticed the EGR passages were blocked with carbon. I mean COMPLETELY blocked. What would cause this? What would some of the symptoms have been? Would this have any other negative effect that need to be addressed?

Thanks for the help....

RKB

 

[Ormand]

It just happens over time, especially if the valve guide oil seals get a little worn, or something else causes the engine to use a little oil. The symptoms would be part throttle knock, if any. If you're running good fuel all the time, you might not see the knock. Just clean out the passages, and fix everything else. The only negative effect I know of is higher NOX emissions, but if it passed any required tests, then it was just a "theoretical" negative effect!

 

[Sinister6]

If the previous owner ran the car with a bad turbo seal for a while, would that cause it?