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Cadillac EGR Valve Cleaning

By Bill

Two things can happen with the electronic EGR valve: 1. Deposits can build up and hold the pintle off the set. 2. The shaft can build up deposits that cause it to stick in the base of the EGR valve (between the EGR passage and the coil above) when the shaft gets hot and the valve is opened.

The deposits part is pretty easy. Just go in there with a small round wire brush and clean the passages and the walls of the passage.

The shaft can be cleaned with the carb spray...just hold the valve right side up so that solvent doesn't run down the shaft into the coil. The solvent will not hurt the "valve" part of the valve, just the coil windings in the can above.

Just get the big deposits out.  The exhaust will cover the passages with soot soon anyway, so you aren't looking for squeeky clean...just get the major loose deposits out.   If you hold the valve pintle open and bend a little "hook" on the rifle cleaning brush you can swish it around the seat from below.   Getting the shaft clean is the most important thing I think unless you see some really big chunks of carbon in the passages.
 
Sometimes, if the valve hangs open on a piece of carbon, it really isn't from the valve itself, but came from the exhaust manifolds.  I have even seen tiny bits of welding flash (or "grapes" from the sheet metal or tubular fabricated exhaust manifolds) caught in the valve.  In that case all that is required is to remove the offending piece of debris.


bill