High EGT Range
 

Still trying to work out the problem with my '05 2500 4x4. Still getting the intermittent PO299 Turbocharger underboost code that throws me into limp mode. Been to the stealership and even the "guru" there has never heard of this problem for this motor, only for the new motors. I've yet to be able to get it to them while the cel is on. However, not that it would seem to do any good, because they want to throw parts at it instead of determine what/why the problem is occurring, and I'll have no part of that (actually my WALLET won't have any part of that).

So here's the only common occurrence since the problem started: Higher than normal EGT's.

My normal range, highway, cruise at around 75mph, was 800-850*F @ 8psi. Going over a high rise bridge such as crossing the MS river in Baton Rouge, or through Bridge City, I could maintain 75mph on the incline and still barely touch 1000*F @<18psi.

Now, and since the problem has started, I notice that my normal cruise on the highway at 75mph rides 900*F @ 2psi more often than not, and accelerating to get to speed, or crossing the same high rise bridges, I hit 1400*F QUICK and still don't see over 6-8psi! I have the Bullydog Triple dog w/outlook, and since the problem started to occur, I have uninstalled the proggie, and returned to stock, with no improvement.

I have noticed though that even though I have uninstalled the BD, my exhaust is still rich.

I can't positively identify the issue. Turbo? MAP? Fueling system? The turbo is nice and clean, spins effortlessly with the fingertips, no slack/slop, and you can hear it trying to spool up tho the tone isn't what it used to be (I've gone from hearing a 747 to hearing a cessna, lol). Waste gate operates freely, no slop or sticking points open/closed. Turbo-to-manifold ducting is snug and no leaks found (though I'm not overly confident of my test procedures). MAP sensor is nice and clean, no dirt/trash/discoloration. NO back pressure on exhaust. PO299 is the only CEL code that has ever come up from day one.

:argh:

I'm simply lost at what else to do to the dang truck, and now I've really gotten myself into a pickle since as of Dec 31, I am officially an unemployed statistic. Company laid off nearly 500. #^@&ers.

Any suggestions on what I may have missed? What else is there to check?

sounds like a boost leak since yer missin about 10psi.....................I would suspect the boots, please explain how you checked for leaks

sorry bout the job man :madd:

Built a turbo "plug" with a 3" to 2" rubber coupler (for drain pipe). Drilled and tapped a 2" pvc plug to accept a schrader valve and 0-50psi pressure gauge. Fought for about an hour to force the 3" side up and onto the turbo intake flange (3" too small, 4" too big). Had to use some wd-40 and trim the lip off the inside of the rubber to get it to fit over the turbo. What a PITA.

Set compressor regulator to 12psi and let her rip. I never showed any pressure on my gauge at the turbo, but the only place I could find the air escaping was at the exhaust. I sprayed everything down liberally with soapy water looking for bubbles, and never found any. Often wonder if I should have used a boost gauge instead of a normal air pressure gauge, don't see why it would matter in this application, though. Even though I was putting a regulated 12-15psi into it, I wasn't brave enough to plug the exhaust to force the system to build pressure. My luck and with the track record I've got around my place for blowing things up, I'd have a million pieces of intercooler all over my back yard.

Checked and double checked all boots and clamps (not the factory, these are upgraded heavy duty suckers) and all seem fine.

Is there maybe something I should have done differently? Is there a different method for checking? Or have I skipped a step in the process and my mind just doesn't see where? I'm subject to do such things!

when your drivin down the highway and let the pedal all the way out then slowly bring the throttle back in do you hear a funny rattling noise it almost sounds like an injector sticking

yer pressure check was addiquate

now I am wonnerin bout other things?????????????????

No, haven't noticed anything similar to that. The turbo is the only sound difference. Before the issue, it sounded like a jet taking off, now it sounds very similar to the little KKK and garret turbos the mercedes 3.0's run. It's still there, still whistling, just not scaring the b'jesus outta the local birds anymore! lol.

Even when it's in limp mode, it runs like a "good" n/a diesel. Very much like the old 90's n/a powerstroke in my buddy's F550 wrecker. It's got plenty of power, so long as you don't need it over 55mph or more than 2100rpm running through the gears.

As of right now, I'm just shy of dropping the down-pipe again and looking at the exhaust side of the turbo just to make sure I haven't melted anything.

When I first bought my truck I but a bd ram x power chip on it that chip maxed out my rail pressure at 27k hitting the relief at wot after about 6 months of that i lost power and my egts sky rocketed didnt think much of it kept driving it took the bd off and purchased a smarty well the smarty helped but the damage was already done about three months after the smarty my engine one day just started burning oil pulled the head and #4 piston had a hole all the way threw it took the injectors to have them tested and three of them the tips were split rebuilt the engine installed the dragon flow injectors and havent had problems since my egts a 70 are around 600 at wot around 950

Well, I think I can monitor my rail pressure with my outlook, I'll check on that and post findings. I'm definitely not burning or loosing any oil, and even reaching the 5k miles mark since last oil change, no noticeable drop in oil level on stick. I often wonder if it's an injector issue causing the heat and exhaust haze, but not sure how to verify.

When I first bought the truck, with BD installed and set to extreme, the egt's never got over 1250 even when getting on it hard. I drove it for a year or so like that before any problems arose. I'm a light footed driver 99% of the time and have always kept a watchful eye on the outlook for egt's and boost pressure. It was a year of driving before I ever even knew that there was a defuel setting (which was set to 1300) and it scared the crapola outta me when I first noticed that I hit that range, and it's been down hill since.

OK. What I can monitor is the Injection Control Pressure. Don't know if these values help any, but here's what I'm reading:
IDLE: 6000psi (+/-10psi)

transmission in neutral, engine unloaded:

16000psi (+/-20) @ 2krpm (0psi boost)
20000psi (+/-20) @ 2.5krpm (1psi boost)
23750psi (+/-20) @ 3krpm (1psi boost)

transmission engaged, from dead stop to 70mph, WOT:

Max reading 19k psi before shift points @/around 2.5krpm
Pressure ranged from 8k-12k while wrapping up from dead stop and from the bottom of each shift, pressure would begin to peak from 15k-19k right before each shift point.

In this test run, max boost pressure was 7psi, I let off the throttle at 70mph when the egt's hit 1400*F (was still WOT)

Any of this helpful?

Im almost positive its the injector tips the only thing that makes egts go up like that is extreme overfueling but here in a little while i will do the same rial pressure test on my truck

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Ok here are my results: Trans in nuetral: Rial pressure: Boost pressure: 16000psi 2psi 18000psi 6psi 20000psi 10psi Trans in gear: 40 mph 17000psi 4psi boost On highway from dead stop wot: 825 deg. egts 0 to 70 22000psi rail press. 37 psi boost cruisin at 70 18000psi 8 psi boost you can just change the tips but before you do that make double sure you have no leaks in your intake system after the turbo on the boost side and when i diagnose a low power complaint i read boost pressure when its low it doesnt always mean that the turbo is bad it could also mean that the engine isnt performing strong enough to spool up the turbo and if it was the turbo you would know it because you could see the damage just by looking at the intake side of it

Looking at the turbo from the intake side, it's absolutely nothing abnormal, nice an clean, sharp edges on vanes, everything's as it should be. As for motor not performing strong enough to spool turbo, I dunno, but I know that even in limp mode, I can hit the "tow/haul" button and climb pretty quickly to 3krpm with WOT. The motor simply feels like a good, strong, NON-TURBO motor, unfortunately, it's a TURBO motor that's supposed to be acting like a turbo motor, but ain't. I guess what really has me off guard is the fact that I appear to be getting more fuel than I should, assuming that if the turbo is NOT producing boost, or the boost being produced isn't getting to the intake *where the map sensor is*, then shouldn't the computer be cutting fueling back in absence of boost? I would understand if it were a boost leak, and the map sensor was at/near the turbo, but it's at the receiving end of the plumbing so what it reads is what fueling should be rated by, correct?

I remember why I like things with fuel enrichment valves and ALDA's and no computer's in lieu of manual linkages and vacuum diaphragms and such. When something broke, you could point at it and say "yup, see that? It's broke!"

I can't even get the dealership to provide me with the operational ranges for the map sensor. They have no diagnostic anymore, it's change parts until problem stops, and then bend customer over counter and CHARGE!!!