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Left field time, pull both the exhaust and intakes , hold the compressor wheel and try to turn the turbine wheel.
If you have access to another turbo I would try that.
Cheers Steve
 

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Are there any, any other places intake air can leak after the intake plenum? When I plug it up to air on the turbo, it loses air and I can hear it but it sounds more like the back driver side of the engine. Is that the normal place where the air would go out?
I am having a hard time understanding this. But pull of boot off the intake horn. And plug it with a plumbing cap. Then pull the boot off the turbo and get another plug cap and thread an air fitting into it. Hook up air through a regulator and give it 40 psi. Listen for leaks. This will test the entire air system from turbo to u take. Eliminate that. If that’s what you did then ok.

Next hook up the intake side and feed it air. Listen around the intake shelf to see if any gasket there is leaking. If not then I’d say your turbo has something wrong with it. When you push air into the intake you might have some leave the crankcase vent. Depending what valves are open.
 

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Discussion Starter #63
I am having a hard time understanding this. But pull of boot off the intake horn. And plug it with a plumbing cap. Then pull the boot off the turbo and get another plug cap and thread an air fitting into it. Hook up air through a regulator and give it 40 psi. Listen for leaks. This will test the entire air system from turbo to u take. Eliminate that. If that’s what you did then ok.

Next hook up the intake side and feed it air. Listen around the intake shelf to see if any gasket there is leaking. If not then I’d say your turbo has something wrong with it. When you push air into the intake you might have some leave the crankcase vent. Depending what valves are open.
Yep I tested it both ways like you mentioned. Only gave it 20 psi air though.
 

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Discussion Starter #64
Left field time, pull both the exhaust and intakes , hold the compressor wheel and try to turn the turbine wheel.
If you have access to another turbo I would try that.
Cheers Steve
I just tried turning one side while holding the other, they’re connected :/. So no problems there
 

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Discussion Starter #65
My thoughts sometimes go to that afc diaphragm. What if the spring under the fuel pin is too tough and my boost never gets to push the pin down? Well obviously with no boost that pin never really goes down. The rod on the pin doesnt stick though. Just wondering what would happen if I ran the truck without the spring in there? The one that holds the fuel pin up.
 

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If the diaphragm does not go down you will not have fuel for more than about 10 PSI, You can get around 10 PSI boost with a THD pin turned to the backside and therefore no extra fuel. Tried it once to see what would happen. Are you sure your boost gauge is good?
 

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Discussion Starter #67
If the diaphragm does not go down you will not have fuel for more than about 10 PSI, You can get around 10 PSI boost with a THD pin turned to the backside and therefore no extra fuel. Tried it once to see what would happen. Are you sure your boost gauge is good?
Yeah cause the gauge goes up when I plug it to shop air. And the truck id performing badly. Thanks for the info on the pin, guess it’s not that.
 

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Yes it should be spinning if the motor is running. My hx 35/qsv was almost at 1 psi at idle(73°EGT worth of throttle was 1psi no load) with a nice whistle from both ends. At all times.

You hear the turbo whistling as its spools, that means it's doing some work and the gauge is not registering it, nor is your engine responding to the additional air(that may or may not be getting to the motor or gage ). Try pulling the boot at the intake horn, verify flow changes with motor rpm.( be careful no resistance on the compressor means it can overspeed if you rev too high)

Oil leak ... is it coming from the pump it self insted of the gasket, oil or is it fuel ?

Air out the draft tube
Yes the piston rings are susposed to pass air on a leak down /boost leak test see ring gap. The question is is it excessive? Do the "Cummins blow-by test" to investigate further. Most don't like the blow by test because it does not identify the source of trouble just a presence of it . You should normally also have air coming out the exhaust as normally at least 1 pair of valves are in overlap.

Radial Shaft play...
None =locked up /damaged bushings
It should move side to side a few thou, there is a +/- spec, so long as there no housing contact is typically considered a pass. Look for shiny patches on the housing where the intake wheel may have made contact.( shiny patches don't equal non-functional that hx35 experienced a paper towel going through it, it was missed when finnishing the Allison install, damage was done but it survived 30k mi, had two shiny patches devlop over time(14mo) in the intake housing from contact. all the blades showed minor contact damage it needs a CHAR for repair still made 28psi on stock fuel )
Thrust( in and out ) should be tight, almost 0 There is a spec for what shoule be there.

Temp turbo swap..
Sounds like it would rule out the turbo as the failure.

Trans ..
Still a possibility?

IP..
Problems not ruled out
 

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Discussion Starter #69
Yes it should be spinning if the motor is running. My hx 35/qsv was almost at 1 psi at idle(73°EGT worth of throttle was 1psi no load) with a nice whistle from both ends. At all times.

You hear the turbo whistling as its spools, that means it's doing some work and the gauge is not registering it, nor is your engine responding to the additional air(that may or may not be getting to the motor or gage ). Try pulling the boot at the intake horn, verify flow changes with motor rpm.( be careful no resistance on the compressor means it can overspeed if you rev too high)

Oil leak ... is it coming from the pump it self insted of the gasket, oil or is it fuel ?

Air out the draft tube
Yes the piston rings are susposed to pass air on a leak down /boost leak test see ring gap. The question is is it excessive? Do the "Cummins blow-by test" to investigate further. Most don't like the blow by test because it does not identify the source of trouble just a presence of it . You should normally also have air coming out the exhaust as normally at least 1 pair of valves are in overlap.

Radial Shaft play...
None =locked up /damaged bushings
It should move side to side a few thou, there is a +/- spec, so long as there no housing contact is typically considered a pass. Look for shiny patches on the housing where the intake wheel may have made contact.( shiny patches don't equal non-functional that hx35 experienced a paper towel going through it, it was missed when finnishing the Allison install, damage was done but it survived 30k mi, had two shiny patches devlop over time(14mo) in the intake housing from contact. all the blades showed minor contact damage it needs a CHAR for repair still made 28psi on stock fuel )
Thrust( in and out ) should be tight, almost 0 There is a spec for what shoule be there.

Temp turbo swap..
Sounds like it would rule out the turbo as the failure.

Trans ..
Still a possibility?

IP..
Problems not ruled out
Hey Gumby thanks for the post. Yes it has the very minimal side to side play in the shaft. So I just swapped in an HX35W with the 12cm exhaust housing.... still no boost. :(. That sucks. I have gone over the afc housing diaphragm to look for leaks, as well as the reference line to the AFC. When I open the oil fill tube while it’s running it just barely vibrates and moves. At this point it must be somethin wrong with the engine, I feel like I’ve gone over everything. At idle it has no boost so not 1 psi like you mentioned. So I guess that rules out the trans. This sux
 

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You say that the IP looks rebuilt well I can tell you that a rebuilder will set the pump up at stock or below settings. When I had my IP rebuilt the guy asked if I wanted it turned up 20% so I said ok. Well when I got it on and went for a drive it would hardly go compared to the way I had it setup. I turned the Power Screw in about a turn and a half and was back to normal.

I would suggest turning the screw in a turn to see what it does, if it can't get fuel it won't make boost.
 

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The engine is just a giant air pump. With no blow by or knocking I wouldn't suspect you have a major issue.

My mind leans toward a fueling issue. Either an issue with the VE pump, injectors, or maybe your trans.

If the pump timing is way off or if you have an injector dumping fuel you may get poor fuel burn leading to smoke and low boost.

Sent from my LM-G710 using Tapatalk
 

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With the new turbo is the lack of boost when driving? Apart from the lack of boost is it still driving the same?
 

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Discussion Starter #73
I didn’t go past the driveway right when I installed cause the idle boost was still zero and driveway boost was zero. BUT GUESS WHAT. I just bypassed the intercooler with pvc and elbows and the driveway boost went to 5psi! Couldn’t go on the road cause the hood can’t shut. But when I plugged it up to air I couldn’t find an intercooler leak. Can it be fixed or should I upgrade to a f250 intercooler like I’ve seen on some threads? Thanks all for the help. I will try turning my ip up some once I fix the intercooler leaking. 5psi is about the highest I ever got before and that was on the freeway in od.
 

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No inter cooler leaks but bypassing you gain pressure?
Sounds like you may have a plugged cooler.
You could put the plumbing back to stock and move your boost tap to the turbo side of the cooler and recheck boost.
Cheers Steve
 

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Now pull the boost tube ( carefullying) dose it spool ? Yes, pluged down streem remove happy meal toy from intercooler. No, turbo $hit the bed.
By pass achieves the same result ic pluged , remove hapymeal toy(or what everis plugging the ic)... 5psi is record boost for the truck come sounds like it's been working on plugging up for a long time.
thd has a (almost) bolt in up grade Ic/ac/trans cooler unit. I've been eye balling as an alternate to the 7.3 ic. There web site is not clear $600 - for the ic or is that just the shroud ?
Did the EGT come back down to reasonable? probably too short of a run to be able to tell on a driveway only run. Pull the Ic run the pvc through that space , but keep it short 200°f + compressor discharge temp @10psi pvc will soffen ( if you got your problem solved 10lb is easy on stock fuel)
HX35W12 / QSV (Quick Spool Valve diverts the front passage into the back 6cm of the divided 12cm scroll) idle perssure is like .5-.75psi just off idle for 1psi . This is drive way, no load (Neutral) 18psi @ no load gov. 28 peek ,valve opens @20psi closes @15psi
 
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