No Boostage--What Gives?
 

1997 Dodge Cummins 12V, OE turbo (HX35) and P7100, 215hp/440lbs.ft.; a 4-inch turbo-back pipe the only mod (if you don't count the boost gauge and pyrometer) (and the fact that it ain't in a Dodge no mo').

I noticed the boost gauge wasn't moving; duh. Gotta be the boost gauge feed hose. Nope--no joy. No compressed air leak sneakin' out at other ducting joints twix compressor outlet through intake manifold top, neither.

Then I went for a ride, city streets and highway and just had to mash the stoopid pedal. Repeatedly. Nothing...well, a strong naturally-aspirated diesel, but no turbocharger surprise for obnoxious rice-rocket fart boxes. No fast-building EGTs nor black smoke, either.

Then I filled up...and the thing is getting way better gas mileage. OK, no boost, no fuel enrichment, I sorta gets it.

I pulled the air filter hose off, and fired 'er up. The turbine sucked air hard (I still have to explain my to my neighbor 'bout his missin' cat...:w2:).

Obviously, the fuel's pump's not seeing any reference boost along with the engine not seeing any manifold pressure.

Could it be the wastegate is stuck open? Underneath, the wastegate and its connecting rod moved easily by, er, finger.

What is going on?

Eddie

I would say WG...

Pull the cac pipe @ intake and power brake it and see how much air is movin ..:humm:

the wastegate rod should not move easy it should be spring loaded closed. That is where you should look for your problem

Thanx, guys, I'll jump on both suggestions in detail manana after I gets back from running.

Gots other plans for tonight, which may involve mugs of a certain cold, frothy, amber liquid. :c: IT's FRIEDAAY!

Eddie, The

:c:.. any new results ? :pca1:

Ummmm...nope

(whining) In my pathetic "defense", it rained all weekend and today as well (sniff). Truck sits in driveway, and I might have gotten wet!:cry:

Eddie

LMBO !!!!!!!!!!!!!!!!!!!!! :jump:



Glad I aint the onlyone who melts !!!!! :c:

YAY! I Likes It When Somebody Gets It...
 

...don't know that your "Getting It" is a mental health Reel Good Thing, tho...Beware...




Super-nice day outside today, so I had no excuse, er, "reason" for not flopping a chunk of cardboard* down on the driveway and sliding on it underneath El Troca Blanca and trying to move the diaphragm-to-wastegate connecting rod; "trying" being the operative word here.

And Herself had the only working flashlight in the house (the bit@#h) so I couldn't use that excuse, err, "reason"; something about "Hurricane Preparedness" (I always thot "Hurricane Preparedness" meant filling the bathtubs fulla I ice and 108 cases of cheap beer). Nobody wanted to hear about the swarming mosquitoes, lying on vicious pecans on concrete, nor my gettin' eat up by the Ebola, neither.




1. Wastegate wouldn't move, both with (a) direct connecting rod hand pressure/hand torque on the wastegate valve axis' throw (the connecting rod that connects the wastegate's valve's axle via (b) the connecting rod itself.

Keep the connecting rod /crankshaft analogy in mind; we're talking about a con-rod/crankshaft small-end relationship here. Sooooo...the connecting rod could be seized OR the spring could be too stiff for the slight amount amount of pressure I could put on it; a really convoluted reach to that connecting rod--one of those arm-reaches where you really need four or five extra elbow joints (available via alien abduction, I hear, "probes" included. Handy, but forgettaboutit). I seem to almost remember my being able to move that rod before, though (scary thot, that).

2. The wastegate's "small-end" crank throw was positioned across the centerline of the turbine downtube, i.e., across the exhaust flow. In normal mechanical terms, the valve should be closed.

Didn't try checking compressor output directly; maybe tomorrow. Maybe not. Keep in mind that there is a small fine-thread metric nut (a 5/16 hex bit almost works here) that I gotsta unscrew. My battery-operated drill battery was dead, which means I hadda recharge it. Never mind the 5/16 bit wasn't screwed in. I woulda hadda get out my 125VAC drill motor and an extension cord AND that would have been work. (sniff)

Eddie


*Cheap-ass chinese cardboard IS superior for sliding across 'cause it's so slick (from all the lead that puts in it).

I like the humor in this, but it makes responding difficult. I'll be the straight edge guy that doesn't drink here! From the sounds of everything... What about a bad boost gauge itself.

Sounds like you may have a stuck waste gate then ... :s: thanks for the read .. LOL:c:

Oh, The Fun Goes On
 

I don't get to drive The Thing but on weekends...walk to bus depot, take a direct bus to downtown, walk to my office. Rinse and repeat, daily. (snivel-whine-moan) (sniff)

1. Good almost-catch on the boost gauge itself. I fingered it was the boost gauge line and/or joints, which I checked again tonight...no love, GONG!:tttt:

Then I ripped the boost gauge out of the console and, umm, "rigged" it to my scuba regulator through another adjustable generic regulator I have, set at 10, 20, and 30 psig. I guess this counts as a "loss"*, since the gauge read perfectly.

Also, as part of flushing the cooling system out, I ran El Troca Blanca 'bout 200 miles this weekend, continuously, just trying to get it good and warm so the cleaner stuff could work--and some of that included getting back onto downtown freeways. The poor thing couldn't get out of its own way on the onramps; it "accelerated"...not. It was embarrassing. I'm satisfied that yes, indeed it is a diesel. Just not a turbocharged one, with no manifold pressure and i.e. nothing to show on a boost gauge.

2. Wastegate diaphragm chamber and pushrod: I am plotting to pull that apart this weekend, if indeed it can be pulled apart; I'll have to study up on that as I know nothing about Cummins Holsets. Links?

Eddie












*OK, parable time chilluns:

Walked into a bar, mid-morning, and ordered a draft beer (the bartender was busy, picking his nose)(classy place). The only other people a-sittin' at the stools were a dweeby Prius-drivin' wad (drinking a, not diet Coke, but diet Pepsi!), a leather-clad, tattooed stereotypical biker, and my entirely normal self. The bored bartender stayed behind the bar, watering down the beer and not entirely awake.

Biker to Prius guy: Citizen, I betcha $5.00 I can pour this beer over yer head and not get you WET.

Prius Guy, with a supercilious, I'm better-than-you sniff: "Well, I'll just take that bet". (to itself) "Heh! Easiest five bucks I ever made in my life! This low person probably drives diesel pickup as well as a Harley and thus leaves a huge carbon footprint and therefore is guilty in the eyes of the lords Algor and Obama and deserves to be shown his place."

Biker pours beer all over Prius Guy; Prius Guy sputters imprecations and drips; Bartender laffs his butt off (but does not part with a water-down round on the house); I spew beer-ish water though my nose.

Biker sez to soaked, watered-beer smellin' Prius Guy:
Well. I guesses YOU wins THAT one!

LOL...


have you inspected all the boost hoses.. ?

It would seem that kinda odd .. can you hear your turbo spooling ?

Yup. That was my first suspicion, Occam's Razor. I'm going to go back over everything in clinically minute detail this very weekend, every obvious and hidden joint where compressed air could be leaking...but it would seem to me that a.), I'd be able to hear a released compressed air hiss, and b.), be able to easily see the leak capable of passing the volume of air required for a, say, 6-12 psig.

I think so. Open dual pipes (somewhat loudish) (open windows, lot or freeway noise plus 10-31x15 tire noise), but I'm pretty much sure I heard the blessed whine when I put the engine under load, i.e., the freeway on-ramp pedal-to-the-metal and other accelerative occasions.

Ya think? Frankly, this'n has me buffaloed; it's got to be something stupid-obvious that I'm just not seeing (typical)--or something expensive. :sos:

Eddie

Yeah .. Bound to be something retarded and like .. Oh .. No CHIT !!!! THAT THEER'S A LEAK .. LOL:jump:.. I FOUND THE PROBLEM !!!!! ... I have had manny of these revelations in my life .. but I'll digress .. :c:

Yup. Found It...
 

...and there goes my excuse to go rush out and buy a Precision Turbo Ball-Bearing turbo. Sigh.

So there I was, teetering away on top of an upside-down plastic 5-gallon pail, pretending to attempt (snicker) to "balance" while looking toward the center of the engine compartment and leaning precariously over the fender (meaning my manly parts would get soundly smacked when said bucket tumped) (it did:scare2:)...but just before it did its inevitable Homer Bucket thing ("thang" down here in south Texas) I spotted IT. YAY! OWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW!

Bright shiny threads in a hole at the extreme end of intake manifold back by the firewall; the bolt or the plug backed out, just to f..., I mean, "screw" with me.

Haven't been able to match up the threads, yet, and I'm beginning to thing it would probably be easier to pull the intake lid off and make a full-scale production out of this.

eddiE

fine thread american 1/4" :pca1:

"Well, Dad, It Was Sorta Like This..."
 

OK, there I was, minding my own bidness one fine Sunday, playing truck out in the driveway when space aliens abducted me and attempted to probe my brain cavity but threw me back in disgust 'cause the zombies had beaten them to to it during the recent Zombie Apocalyse but I fooled 'em ALL 'cause I took said brain out and was playing with it AND FORGOT WHERE I PUT IT! HA! TAKE THAT! I GOTS NO BRAIN! WINNING!:tttt:


My first thot was that hex head plug, like the OEM others in the lower manifold; it probably backed out, and since I have both American 1/8" NPT and 1/8" BST (supplied with my SAE and MetricTap & Die sets) taps, I tried greasing them up running them down that ol' hole (woo hoo!).

Neither would start, which is not surprising as that hole is within 3-4 inches of the clutch master cylinder or brake servo and therefore very hard to get a straight shot at, much less put any straightline pressure on.

Either tap shoulda started easily were it the correct thread; same for the 1/4"-20 and 8mm-1.0 taps I tried.

INTERMISSION :pca1:) (Some "lemonade" guzzled)(then some more).
"Duh--possible broken off hollow-body brass fitting." I included hex-head plugs in the brass fitting category. Perhaps the thread I saw was further down the hole, past the 'rind' of the broken fitting left in the threaded hole. "Well", I thot, "I'll just run a #4 EZ-OUT down that ol' hole and back that thang outta there..."

"HEY, GROOOOOVY MAN"
Forgetting for a moment that the EZ-OUT's flutes were going to leave grooves in the soft brass and soft cast iron if I put any meaningful torque on the removal tool, I...put some meaningful torque on the removal tool. Then I noted some BRANDY-NEW meaningful grooves in the material in the hole.

Then decided to give up for the day 'cause the mosquitoes were BITIN and therefore I needed more mosquito-repelling "lemonade" in my system, NOT because I was in the least bit worried about screwing things up even worser.:jump:

Eddie, The

Well, I'm Reading The Manual, Now
 

It turns out that it wasn't that threaded hole (that something threaded backed out of) in the lower section of the intake manifold; that was simply a horizontal bolt boss for the engine hoist sling. Didn't go through to compressed air channel, phooey.

I'm reading the manual now. :drama: "Real men don't need instructions", I know, I know (sigh).

Next test needs to be putting my bicycle pump to turbocharger actuator and my dial indicator to the actuator/wastegate link and actually see if it moves at all--book sez I'm looking for .0013-.050" which is a whole lot less than I thought (or can see from above...)

Eddie

So .. is it fixed yet ??? :pca1:

:pca1::pca1::pca1::pca1::pca1::pca1:
:yum::yum:

Hmmmmm...
 

In a word, "Ummmmm...":blush:


Do I detect a common thread of impatience? It's not the end result--it's the journey. "Zen and the art of a-fixin' things beyond repair". PROCRASTINATE NOW (or later maybe)!

Maybe I'll mess with it this weekend; "Winter" is here, and its REEL cold out--'sposed to hit the low 40's tonight. :nshock: And rain. So not only might I get wet, but Polar Bear cold.

Eddie

OK, Y'all Can Stop Holding Yer Breath Now
 

Found it :jump: a couple hours ago.

In a word, "Gauge". Yup, the gauge itself was blown out, itself a plastic crap AutoMeter leftover from the turbo 5.0 Mustang Good 0l Days of (Sheeze, was that 1987:scare2:)

BTW--I now knows the turbocharger IS NOT going to separate from the OE exhaust manifold.

Eddie