I got the same sound that he has been describing... and I took my red line off and plugged it.. before I was getting 17 max at WOT, and when I took the red line off i was getting 22 at WOT.... Is this normal?? What do I need to check for on the waste gate selenoid??

 

I would also agree that it sounds normal.

 

i have the same sound. less boost also. it was like a low putch howl/wine. my turbo ended up being bad. pulled the intake pipe off and pull on the shaft there should be .006-.010 thousands of play, mine had .060! and truck only has 76,000 miles..... my rebuild and some other PMS goodies come in monday...

 

Man, reading this is giving me PMS! I need more money!

 

Well I plan to pull the turbo off to install the wicked wheel. When I had the tuner I could get 22-24psi of boost. I have a new tuner on its way I am going to try it with the wicked wheel. I cannot believe that the continuous noise with only 4 lbs of boost would be normal at 60 and loading it up heavy.

 

Was the truck at normal temp? My truck blows alot of boost when the motor is cold. If you are on the gas, but not much load the wastegate will stay open. My line to the wastegate is pluged, but will still do it if the motor is cold. Get a DP tuner so that boost number will be around 30 not 11.

 

Running down the I-state so it was normal. I will not be plugging up my wastegate line anytime soon. I bought this truck for longevity. 30lbs puts a lot of stress on these motors. I plan on getting several hundred thousand out of this truck.

 

Chris beat me to it.
You have an open intake and a spinning turbo.
You are going to be hearing that Darth Vader sound.

 

My question is why would it do this. I am putting the motor under load and need the boost and fuel to accerate. It seems to me at 60mph and the pedal pushed to just before it shifts down and only 2-4psi of boost is low. Is that right?

 

sounds like the wastegate or ic boots. Have you checked them for leaks? Is the wastegate stock, and how many miles on the truck?

 

If you don't have any leaks I would check the turbo carefully,at about 55k miles mine got to where it would only build about 4 lbs until I got to 2100 RPM then would boost normally.The turbo was the culprit

 

At 60 mph your RPM's are well under 2000. It's normal to see low boost at lower RPM's. It takes longer to build boost when under 2000 RPM's, and the fact that you are holding the pedal at the point to keep it from downshifting means that you aren't fueling fully either to spool the turbo.

You've already verified that you can reach 15 psi of boost at WOT. Normal max boost for a stock PSD while unloaded is 15-17 psi.

 

Everything is stock and the truck only has about 90K on it. I would be OK with things if their was not so much conflicting responses. I know that describing things is not as accurate but it is 50/50 on the responses. One would think this was normal but ascending a hill I would have to hold it to the floor to maintain 75MPH and steady boost was about 12 PSI. I would hate to pull a heavy trailer. When I would floor it it would jump up to 15 or so then settle back to 12-13. Also EGTs are about 900* or so floored climbing a hill. (Idiots that owned the truck before me installed the pyro post turbo behind the bend at the bottom of the down pipe going out towards the back of the truck so I add ~300* to the actual reading.) I would imagine 2psi makes a difference in these trucks. There was no excessive smoke. As planned I ordered a wicked wheel and a boost fooler from dieselsite that should be in later this week so I will pull the turbo off and find out for sure and clean it up. If it needs a rebuild I would do it to keep cost down so where would I get parts and how much should I expect to spend? It s 10 years old so it is possiable it is bad or heading that road.

 

Well, just to help clarify some of the posts in this thread.

The hissing sound you hear is normal when using an aftermarket intake. Other noises that can be heard with the stock turbo (and aftermarket intake) are the turbo surge and turbo stall. Surge is a continuous chuffing sound when accelerating under load, typically between 1600-2000 RPM's. It is distinctly different than the hissing noise. Stall is when you hear a chirp or bark between shifts. It's a momentary backforce of air through the compressor wheel. Stall is normal, but only typically happens in higher boost situations.

As for your maximum boost. What does your boost maintain on a WOT run, say from 0-80 mph, pedal to the floor the whole time? It should hover between 15-17 psi.

With your mileage, I highly doubt your turbo is bad. There are other symptoms of a dying turbo, including grinding/screeching noises as the wheels contact the housing, smoke and oil out the tailpipe, etc. If you want to quickly inspect the turbo, then pull of the intake boot at the compressor opening, grab the compressor wheel shaft (not the blades) with your finger tips, and wiggle the wheel. There should be little to no side-to-side play, and absolutely no in-out play. Basically the wheel should not contact the housing. That's a quick and easy test. If there is no significant play, then your turbo is fine.

Boost and exhaust leaks are much more common, and cheaper to fix. Boost leaks will have to be tracked down by inspecting the boots in the CAC system. There are 6 boots total. Exhaust leaks are easier to spot, as they show up as soot deposits. Most common leak spots are at the up-pipe collector directly behind the turbo. The donut gaskets in the up-pipes are notorious for wearing out and leaking. Grab a mirror and a flashlight, and check for soot.

Again, suspect boost and exhaust leaks when boost levels are down. If you cannot hold a consistent 15-17 psi at WOT, then you most likely have a leak. If you can maintain 15-17 psi, then you don't have a significant issue at this time.

Hope this helps, and clears up some confusion.

 

another thing to check while you've got it apart is the actuator spring.I found one with a weak spring and was starting to open early