EGR and Clogged Intakes

[mcmonroe]

Could someone explain to me the routing of the EGR in relation to the charge cooler and intake? Is the exhuast gas routed in a way such that it runs through the charge cooler?

The VW guys over on the TDI list (http://www.tdiclub.com) are having some big problems with the charge cooler and intakes getting clogged up with oil and sludge from the EGR process.

It seems like the first recommended change to those cars is to disable the EGR.

I am concerned that the Duramax folks may run into similar issues.

Thoughts/Ideas would be appreciated,

Mark Monroe
Harrisburg ND

[Kennedy]

The EGR flow will not go through the intercooler, but the crankcase vent will on the LLY. LB7 vents direct to atmosphere.

[FlyRod]

What is the big concern with crank case vents? Even my four stroke weed eater is venting back to the intake! Is this an ozone concern?

[More Power]

The 6.5 turbodiesel vented its crankcase upstream of the turbo, which allowed all crankcase gases to pass through the turbo (and intercooler if equipped) before entering the intake manifold. The LLY is now similar.

There is an oil component to crankcase gases, which will coat the interior of the intercooler, pipes, hoses and intake manifold as the gases pass through. Some feel coating the inside of the intercooler with an oil film will reduce its heat exchange properties. I haven't seen any documented tests to demonstrate that, but I would tend to agree.

As JK mentioned, EGR flow doesn't pass through the LLY's intercooler. However, the 2000 SAE paper on the Duramax discusses future emissions regulations and mentioned that allowing EGR flow through the intercooler was a possibility in the future. I hope they find some way around that - passing soot through an intercooler can't be a good thing.

MP