Hey guys,

I am working on Dad's 97 K1500 'S'

It was throwing two OS codes, P0236 and an air duct leak code.

I got rid of the OS codes by replacing the OS with a spare that I had in an old IP.

Now the truck runs ok but it blows black like a freight train at all RPMs except deceleration and idle. I have checked the vacuum and I have 25" at the Vac pump and 15" at the turbo. The actuator rod is sucked in at idle and I can't move it very easily.

Also, when I hold the APP at around 1500 RPM the truck will surge on the road and pour out black smoke. Also, at times while cruising below 80 km/hr the engine will start rattling pretty heavy (like a cold start up) and then go back to sounding normal.

I am pulling out my hair trying to figure this out.

I think I have the IP problem fixed because I put in the new OS on the OEM scribed line and I don't get the two OS codes that I used to get.

I am wondering if maybe there is a failure in the wastegate such that it isn't producing any boost - may have to hook up my boost gauge to his truck to see what is going on.

My questions for you are:

1. What is the cause of the surge (could there be a problem in the way I replaced the OS)?

2. What causes the truck to rattle and then smooth out spontaneously while driving?

EGR solenoids plumbed wrong - one is EGR, other is EGR Vent - or EGR valve is stuck open - block off vac supply to EGR actuator for test.

Rattle is varying advance - ECT or IAT or bypassing advance piston - need a scantool to figger all this out, dude.

Black smoke and surge may also be FS going wacky - again with the scantool - carcode or autoengineuity.

EGR solenoids are plumbed correctly as per the diagram on the fan shroud...

Tried another EGR valve - no change

Tried known good ECT - no change

I don't have a scan tool so I am trying to do this by taking out all of the variables possible...

If anyone else wants to chime in please feel free...

The truck is blowing HUGE amounts of black smoke at any RPM except idle and deceleration.

The only codes coming up are for the turbo P0236 and the air duct P1191 or something like that...

The turbo actuator is getting 15" of vacuum and the actuator rod is sucked up into the actuator - will stick on a boost gauge tomorrow to verify boost.

When driving and holding the APP steady the truck will surge and go from running smooth to rattling...

Tried new PMD - no difference

Moved OS a little both ways - no difference

Should I stick in the spare IP tomorrow?

Any other tests I can run easily?

LP passes, PMD passes....

Mystery gasket missing under upper intake.

Nope....brand new mystery gasket (bought it today)

DP - could the OS cause this type of problem if it is not installed properly?

I lined up the edge of the sensor housing with the OEM line that was scribed on the cam ring...

yep
To far toward the PMD, Makes lots more fuel

Would it cause the engine going from running smooth to rattling spontaneously?

BTW - surge problem was present prior to OS R+R when running off of the CPS...

Sure a field 'n stream critter hasn't taken up residence in the airbox?

Some sort of air path blockage, even soaked filter?

That's too much fuel for the volume of air, or excess EGR - pull the upper plenum, jam a large dowel in the tower, hold it there, crank it up and see whatcha got

Surging sounds like the FS

Brand new air filter...

Before I dug into the IP the truck was surging but not blowing black smoke like it is now (but the truck also had the OS codes in memory and the SES light on so I am pretty sure it was using the CPS to regulate fuel)

After I replaced the OS the codes disappeared, the surging continued, and now I have HUGE amounts of black smoke...

I still get P0236 and I am not sure if there is something wrong with the wastegate or not because all turbo checks come out good...

When I unplug the OS it still pours out huge amounts of black smoke...

Replace IP?

and it still goes between smooth running and rattling...(didn't do that before the OS was R+R'd)...

Alright....I know that I need a scanner to find out what is actually going on here but since I don't have one I will just replace the IP with one on the shelf and see what happens...

P0236 can be the MAP sensor wiring/connector, as well as the sensor itself.

The air-duct code means the MAF is not sensing the correct amount of air flow for engine rpm and fuel - can be bad MAF, dirty MAF, hole in the elbow, etc - MAF can be cleaned with Diesel fuel, then hot soapy water, then blow-dried - MAF can cause black smoke - can also mean you're running the engine with the upper plenum off, or the turbo hose, or the MAP or IAT is missing

OK....so a bad MAP sensor could be causing both codes....can I swap it with the BARO sensor as a test?

Could - but it won't work :thumbsdow - Baro sensor is +4.95v output at Baro, MAP is +2.45v at Baro - Baro depending on your altitudinal relationship to sea level, of course

Baro sensor is also EGR sensor in "S" series

FIXED!!!

New IP fixed the surging/rattling problem.

Plugging the EGR vac line running to the EGR valve fixed the HUGE amounts of black smoke.

Replacing the corrugated hose from the CDR to the air intake boot fixed the air duct leak.

Installing a 'quickie' turbo master fixed the P0236 code.

All is good again....

PS...





:thankyou2

Good job, Chris! Glad you're all running again ... notivr I resisted the urge to ask you how you got your 6.5 to make all that 'kewl' black smoke? LOL.

jifaire -

You should have seen it.....it was a ridiculous amount of smoke pouring out the back....made the exhaust of some of those sled pulling CUMMINS look like faint wisps of smoke...

:drop_mout

Sweet. Can we figure out a way to do this on command? Say, when a car full of kids playing rap music with a big old subwoofer is right behind us at a light?

Or maybe when some snooty hybrid-driver has just turned up their nose at our diesel truck?

There just HAS to be a use for vast quantities of black smoke!!

Thats what I have been thinking jifaire.... just fill their window fulla black smoke!

Put a valve in the vacuum line to the wg - dumps vacuum to smoke'em - or connect an old-timey throttle cable to the wg - pull it open from inside the cab to smoke'em - then release it when you need some power to get outta there, real quick

Robin - Activate the Bat-Smog...

ROFL

Holy Can't See Squat, Batman!!

Real trick would be to get the smoke & power at the same time :-)