Want to get rid of oil in the intake

[Danish Farmer]

Hi
:hello:
Had my intake manifold and turbo off to change injectors, and the intake is nasty inside from oil probably from the breathing hose.
Wonder if I can just let the breath away in a hose under the truck, and out in the back, instead of having the engine to eat oily air ?

It´s not like my engine has a lot of breath when I remove the oil filler cap, so I guess it just comes over time. Maybe the intake has never been off. The turbo does not have any slack either, so I guess the oil is not from that.

Does the engine need the breath to be vacumed out, like now when the hose is getting ventury wind, and the engine sucks it into the intake. -Or if its enough that the breath just finds its own way out in a 3/4 in hose to the very back of the truck.

 

[NVW]

Just vent it down below the frame, it doesn't need to go that far back.

 

[Paveltolz]

EGR?

 

[Danish Farmer]

Yep, it`has EGR. Intake under the valve has some layer of sooth on it. She`ll problably be happy to get rid of exhaust,
- but I realize, from reading in here, if I disconnect EGR, the truck will need a different thing to plug into the ECM to prevent the SES light to stay on. ?

 

[Paveltolz]

So, like me and many others, you have an "S" model truck and the crap you are seeing inside the intake probably has the consistency of burnt tar as the slight oil mist from the CDR mixes with the hot carbon coming back in.
This was mine after I cleaned up a lot of it.
Still awful looking.

Several ways to eliminate that:
Easiest is to simply replace lower "S" intake gaskets with the "F" intake ones so the EGR returns are blocked. Then the more expensive route: replace the lower "S" intake manifold with an "F" intake. I was able to do the lower intake swap. There is now only a slight oil sheen inside from the CDR return. Otherwise, it is plenty clean.
Here's a my intake swap thread, you can see the old vs new in posts 1 and 2. http://www.thetruckstop.us/forum/showthread.php?17646-Intake-Swap
Here's a shot of the inside about a year later:
Hardly different than when I first put it on.

Whether you swap the gaskets or the lower intake, you can still use your EGR mounted upper intake to keep the stock look and the electronics happy but you'd do well to remove the extra material from the upper intake so it looks more like the "F" upper intake.


Depending how strict the inspections are, and I remember them being quite strict, you could just swap both the upper and lower intakes and bolt the EGR valve on there as another option but you've the challenge of finding the parts.

 

[iamdave0887]

The EGR is the main cause of the crud you found in the intake.

What happens is you get a slight film of oil due to the CDR being routed back into the intake. The soot from the EGR exhaust gasses sticks to the oil and starts to build up on the intake and it's runners.

Clean out the intake off the truck very well. Delete the EGR or "drop a freeze plug into the egr opening hint hint" and 95% of your problem will be gone. After the EGR is gone you'll just have a slight oil film inside the intake.

Just the difference the non-EGR intake made on my K-5 was amazing. The "C" code(6.2 was C and J code, 6.5 is S and F) EGR intake was full of soot. After i saw the old EGR intake i knew immediately why the engine smoked black so bad.

 

[Danish Farmer]

Allrighty, but will it then show a code constantly until the ECM is equipped with a different chip ? -or can the vacum hose be rerouted to fool the SES light to stay off ?
By the way, good illustrations Paveltolz. Thank you

 

[iamdave0887]

If you do the freeze plug trick no you will not have a SES light.

Fooling the ECM when it comes to the EGR circuit is terribly easy. For your vacuum lines you have a T right before the EGR. One side of the T goes to the EGR, the other side goes to the firewall sensor. The third end of the T is the vacuum supply.

If you block off the line that goes to the EGR itself and leave the line that goes to firewall sensor intact, then the computer knows no different. There is no EGR flow sensor on these trucks so the ECM doesn't check to see if the EGR is allowing exhaust into the intake or how much it's letting in. IT just checks to see if vacuum made it to the EGR valve(via the firewall sensor).

Most 6.5s around here are 2500s 3500s 3500HDs, so i haven't done many EGR trucks with computer control. The ones i have done, the above method does work for fooling the ECM, but i'd still drop a freeze plug in the lower intake center hole to keep the exhaust from forcing the EGR valve open.