Wonderful 6.7L EPA garbage. As you can see the EGR valve has loaded up the intake manifold with soot choking the engine for air or boost pressure.

 

Enuf said...

 

Edited July 29, 20168 yr by Mopar1973Man

Ha Ha that'll teach em not to let it sit and idle so much.    

If he didn't notice things long before it got that bad he deserves the repair bill for this. No excuse on his part.

Im' sorry I have to ask, but what happened there? Something about smog set up and long idles Can someone spell it out for me? Thanks in advance.

EGR valves are notorious for plugging up the intake system with an oily carbon mixture that is really hard, this one is packed solid. If you look at the picture the intake tube is taken off and the intake plenum is flush with the top of the head with carbon. It happens normally with these systems but gets a lot worse with excess idling and they are especially bad when combined with closed center crank case vent systems that pull into the EGR system as well which is where the oily part comes in and doubles down on the issue.

On the other note seems like these Cummins engines will almost run with no air, I'm guessing not very well.

I assume the head has to be removed and disassembled and then cleaned some how? How was the truck even running to this point?

That's  incredible. thanks for explaining.

 

Now I know why second gens are holding value.

1 hour ago, leathermaneod said:

I assume the head has to be removed and disassembled and then cleaned some how? How was the truck even running to this point?

 

 

 

No. Just remove the intake cover plate and use a shop vacuum and a tool of some sort to remove the build up. 

 

Cummins isn't the only one with this problem even the VW diesel are really bad about plugging up. Most remove the intake manifold and use a propane weed burner to burn the crud out. 

 

As for the idling. Some place like California where traffic backs up for miles on the freeways or city street it can't be avoided. Even in Boise, ID there are time traffic is backed up to crawl or stand still. Then there are people that own these vehicles and don't drive more than 2-5 miles tops on city streets and never get to operational temperature. 

 

Basically, the whole EGR idea has been a horrid idea even as far back as the 1970's. I had it on my 1973 Dodge Charger and fought with the EGR every smog test. Always passed better without it but had to be operational to pass the test so it would fail if operational. I'm lucky my 1996 Dodge Ram 1500 is a V8 engine WITHOUT an EGR by design. 

 

The whole idea is to dump exhaust gases back in the intake air mixture to weaken the ability of the fuel to burn hot because of the CO² mixed in the air. So this reduces NO_x emissions. The dumb part is if the vehicle manufacturer would quit putting this junk on engine and allow the design for efficient engines then less fuel burned means there is less emissions. Dumping CO² into the intake just means the engine can't produce good power because of lack of oxygen. Then more fuel dumped in to make the same amount of power as an engine without EGR. 

Edited July 29, 20168 yr by Mopar1973Man

I had to pull the intake off my wifes old 03 VW TDI @ around 200K miles due to the intake being mostly caked up too. Hers started surging at highway speeds under heavier load pulling hills. These had a really bad design for the Crank case vent and really got a lot of oil residue in with the EGR gas.

Good subject here. I like learning about this, never knew it could be so bad.

We have a 2011 4500 Ram with 6.7 as a welding truck at work and it has had the egr valve replaced several times because it is plugged and stuck, can absolutely not convince the welders to not let it sit and idle all damn day.

Why not just delete the darn thing? Much easier to deal with that way. Unless you happen to have emission testing or vehicle inspections.

Edited July 29, 20168 yr by JAG1

Was still under warranty yet. I am trying to talk my next in line into adding a programmer and doing deletes next go around, we actually did get a programmer for it but there was a mix up from the company we got it from thought it would work on it but it didn't since it is a 4500 there are differences from 3500 and below pickups, we sent it back and then my boss got cold feet again since it was still warranty.

Nearly a year later on the delete I did for the local here and he's thrilled. Truck runs awesome, good power all the time, no plugged up EGR or DPF problems anymore. MPG is up more and rare do you even see smoke from the tail pipe with the tune I left it on. He loves showing friend at the amount of junk that was yanked off to make a good running truck. Most can't believe it. 

The 6.7 wouldn't be as bad as it is if the intake heater was before the EGR valve. With the grid heater being after the valve you have a ton of surface area for the EGR garbage to grab a hold of... on the bright side it's easy to clean :-)

 

There are some after market grid heater options that may alleviate this issue, Glacier Diesel, but I don't know if they alleviate the issue or just relocate it to the intake passages/valves.