RTH: GTurbo got lazy after highway drive, slow to build boost, lower boost levels than normal (3 Viewers)

[cody c]

Hmm. Im curious what you find with the old turbo.

I crammed a valve stem over the port to my wastegate actuator, then filled with a tire chuck that has a pressure dial on it to see when it started to stroke. The actual pressure it starts to move based on how much tension is put on it, how much force from is on the wastegate flapper valve in the housing wanting to push it open etc.

It gave me a baseline before I swap the H1C for the HX35W, but I bring it up as a method of checking what you got.

Im starting to think the issue is with the waste gate, a bad seal somehow where air is bypassing, or some sort of mechanical conflict against the arm or something. Who knows maybe you find a piece of an exhaust seal in there somewhere.

Best of luck.

 

[Greg_B]

@IanB how goes the healing and troubleshooting?

I've not commented as I've no ideas beyond what has been mentioned, but have been hoping the reason would make itself apparent while you're working through your fixes.

Air or fuel...has to be something affecting either of those two areas one would think eh? I initially thought fuel because you are not belching black smoke, so possibly the fuel rod not being able to move and deliver more fuel with some boost, but you have ruled that out.


gb

 

[IanB]

I'm pretty well healed up again, thanks for asking! But it has really set me back.

I'm gearing up to tear the turbo and manifold back off in January once the holidays are out of the way. I'll be checking to ensure the collar in the split manifold hasn't spun blocking exhaust flow, and giving the turbo a really good once over to see if I can identify the issue. If nothing is obvious, I'll put it back together with the stock turbo to make sure the symptoms follow the Gturbo, and rule out all other sources.

In the meantime, I've wired the wastegate shut per @cody c and it did help, the truck runs better this way than I could get it to otherwise, which reinforces my theory that it's a wastegate issue.

 

[cody c]

If it makes you feel any better, I bought an HX35W to replace my H1C and its been nothing but troubles. Putting the H1C back in shortly till I figure out the cause of the crappiness is.

I had two snap rings not work, one retaining the front half of the turbo popped out and the aluminum front partially separated from the cartridge, and the front thrust bearing snap ring pop out allowing oil to bypass and it wedged between the bearing and impeller. What a pain in the fragging arse this thing, and I still don't know what else is holding it up.

 

[IanB]

If it makes you feel any better, I bought an HX35W to replace my H1C and its been nothing but troubles. Putting the H1C back in shortly till I figure out the cause of the crappiness is.

I had two snap rings not work, one retaining the front half of the turbo popped out and the aluminum front partially separated from the cartridge, and the front thrust bearing snap ring pop out allowing oil to bypass and it wedged between the bearing and impeller. What a pain in the fragging arse this thing, and I still don't know what else is holding it up.

Ouch, I definitely feel your pain!

 

[IanB]

Finally made time to get this done. Got the Gturbo off, and the stock turbo and manifold hanging on the engine this evening, I'll finish putting it back together tomorrow. I'm really hoping when I get to the test drive the stock turbo drives like normal, and I can confirm I have an issue with the engine.

The collar in the manifold was fine, it hadn't spun and blocked flow, which was another possible theory I had considered.

I can't see anything physically wrong with the Gturbo.

 

[IanB]

Start up and test drive took place this morning. I've got a leak at the turbo/coolant hardline gasket, which I reused. It's going to come back apart at some point, so not the end of the world. I'll order another full set of gaskets next time as that should be the "last" time.

I let it idle in the driveway for a while and watched for leaks, letting it warm up (ya right, it's -31C before the windchill, -40C/F with windchill this morning!), ran my mental checklist, etc. Before the stopsign at the end of my street it was obvious that it was working as intended. I was seeing the engine carry boost under light loads again, the exhaust leak noises were gone, and boost is much faster to build.

So the problem is the turbo, and not my engine, my fuel pump/injectors, etc. That's a big step forward here.

I gave the turbo a good looking over on the bench, and not that I know what I'm looking for, but I can't find any cracks in housings, any signs of contact between the blades and the housing, or anything else that looks unusual. I had a real close look at the wastegate adjuster rods on the original and the warranty wastegates, and noted that the original that was on the turbo when the problems started suddenly, has 12 threads exposed (with factory paint pen markings), while the 2nd one had 16 threads. I was trying to bench calibrate the 2nd one with a bicycle pump, and it responded differently on the truck than on the bench, providing only 12psi rather than the 18psi Gturbo sets them at, but the spacers I later added to move the actuator away from the compressor housing are 2-3 times larger than the 4 thread difference in calibration, and it still was an issue, so I don't think it's an issue with the actuators themselves.

I wiped the soot off the hot side shaft end, that's why it's shiny.

 

[gerg]

Spins freely? Shaft play?

 

[ForealBoreal]

Is the wastegate adjustable?

 

[IanB]

Spins freely? Shaft play?

Yes, spins freely, just as tight as when it went in. Nothing unusual there.

Is the wastegate adjustable?

Yes, I commented on that in my post today as far as the adjustment was concerned.

 

[gerg]

I'm sure your feelings are stronger but that's pissing me off.

 

[mudgudgeon]

Firstly- what kind of sasquatch works on a truck when it's -40 outside?

B- have you tried pressurising the turbine housing? Block the manifold flange and turbine outlet, squirt some compressed air in there and see if the wastegate is leaking under pressure, or opening prematurely

3rd- was there any sign of exhaust soot leaking past turbo flange gaskets?

 

[IanB]

Firstly- what kind of sasquatch works on a truck when it's -40 outside?

B- have you tried pressurising the turbine housing? Block the manifold flange and turbine outlet, squirt some compressed air in there and see if the wastegate is leaking under pressure, or opening prematurely

3rd- was there any sign of exhaust soot leaking past turbo flange gaskets?

Oh I work on it inside my garage, which I keep at about 18C all winter! But you can't run a diesel indoors, so out she went, and it was damn cold!

I haven't tried pressurizing the turbine housing...what would you block it off with? I'll have to put some thought into how I can test it.

No signs of soot anywhere between the block and backside of the turbo, no blown out gaskets or soot trails to be found. The split manifold had been leaking prior to the original Gturbo install, but I rebuilt it all at that time, and it seems good.

 

[mudgudgeon]

Oh I work on it inside my garage, which I keep at about 18C all winter! But you can't run a diesel indoors, so out she went, and it was damn cold!

I haven't tried pressurizing the turbine housing...what would you block it off with? I'll have to put some thought into how I can test it.

No signs of soot anywhere between the block and backside of the turbo, no blown out gaskets or soot trails to be found. The split manifold had been leaking prior to the original Gturbo install, but I rebuilt it all at that time, and it seems good.

Could be as simple as have a fellow sasquatch hold a bundled rag over each opening with a shop air blower wedged in the side. You only need to get 20psi or so into it.

 

[BCR4619]

I may have missed it but is the O-Ring good between the turbo and intake cover? Like Mudgudgeon said if you pressurize it it may be leaking out there if its a bad seal, if you take it apart be careful as the clearances are very tight as you can see.

 

[IanB]

I gave up on email support and purchased a long distance plan for my cellphone, and called Australia last night.

Speaking to Graeme, he was puzzled as well, and asked me to split the turbo and send him some pics. I'm no expert, but I don't see anything out of the ordinary here, the only scuffing in the soot is where the turbo housings slide together. The blades are all in perfect shape. The wastegate flapper appears to be centered on the hole when closed so should be sealing properly. Any thoughts?

 

[IanB]

And a couple more.

 

[gerg]

If you gently use both hands can you get get compressor to spin if you keep the shaft in one place?

 

[IanB]

If you gently use both hands can you get get compressor to spin if you keep the shaft in one place?

Hmmm, I'll try that tonight. You're wondering if the shaft is broken or spun?

 

[gerg]

Wondering if torque was inadequate and under load the compressor spins independently. It's a shot in the dark.