04 5.9 unusual noise

[Gonzo 1066]

My 2004.5 3500 6 speed truck in a HARD pull in 5th gear will have a squealing noise. This only happens with full throttle on a warmer day and full 44psi boost. If I back off to 38-39psi (less RPM) the squeal goes away.. The charger is a new Industrial injection Silver Phat shaft. I changed waterpump, alternator,tensioner, and all bearings and drive belt on the front of the engine at 130,000 miles. The noise seems to come on when the cooling fan totally locks up, but I cannot be sure as my wife refuses to ride under the hood in the mountain passes.. Any ideas??

 

[JJPage]

Boost leak likely. Build a "boost leak chuck/device" like this, connect to the turbo and start supplying air, you should find your leak. Be very aware of the danger/injury that can be caused if this blows off the turbo.

 

[seafish]

Shouldn't need more then 40psi to check for a boost leak.

 

[Gonzo 1066]

Good idea, I have one of those made and on the Cummins shelf.

 

[RVTRKN]

40 psi (per square inch) with a 4" radius has a different effect than a 1/4" air line at 40psi.

 

[NIsaacs]

If an intake valve was open, wouldn't that be like an air starter:-laf

Nick

 

[jhenderson]

Only if the outlet isn't plugged.

 

[Gonzo 1066]

The thing got a little more weird today.. HARD pull, started to squeak and continued to make that noise till it was under 15psi man. Still got me puzzled.

 

[cerberusiam]

Did you cleanup the machining around the WG on the turbo before installing it?

 

[Tuesdak]

My 2004.5 3500 6 speed truck in a HARD pull in 5th gear will have a squealing noise. This only happens with full throttle on a warmer day and full 44psi boost. If I back off to 38-39psi (less RPM) the squeal goes away.. The charger is a new Industrial injection Silver Phat shaft. I changed waterpump, alternator,tensioner, and all bearings and drive belt on the front of the engine at 130,000 miles. The noise seems to come on when the cooling fan totally locks up, but I cannot be sure as my wife refuses to ride under the hood in the mountain passes.. Any ideas??

So you changed some parts... New parts don't mean good parts!!! Start troubleshooting over and do not give any part new or otherwise a free pass.

First off I agree to look for a boost leak as they can make all kinds of noise. However, I see load on the fan belt as a symptom.

I have had the joy of listening to a fan clutch or drive belt scream under full fan clutch lockup and max RPM. I didn't keep it up long enough to figure out if it was the clutch or belt that was squealing while slipping. This said with the engine off I would spin the fan by hand in both directions to check for noise. Then remove the drive belt and feel every bearing accessory by hand for play and noise.

Next look at belt alignment and condition. The fan at full lockup takes serious power at high RPM. A stretched or glazed belt although 'bad' is indicating other problems except if it is just old/high miles. Specifically is the tensioner the proper part number and has the correct spring tension? Any pulleys out of line?

I have had Communist China knock off tensioners sold at Autozone with weak springs. I figure they used the tension numbers for a later year (GM) that has the AC compressor after the tensioner. The older year, mine, has the compressor before the tensioner requiring the tensioner spring to deal with the AC compressor load before the crank pulley. It would sequel like crazy trying to get the AC going. I had to get a dealer part to solve the problem as the Autozone junk wouldn't.

Is the AC on during the noise episodes? Possible compressor locking up.

 

[Gonzo 1066]

So you changed some parts... New parts don't mean good parts!!! Start troubleshooting over and do not give any part new or otherwise a free pass.

First off I agree to look for a boost leak as they can make all kinds of noise. However, I see load on the fan belt as a symptom.

I have had the joy of listening to a fan clutch or drive belt scream under full fan clutch lockup and max RPM. I didn't keep it up long enough to figure out if it was the clutch or belt that was squealing while slipping. This said with the engine off I would spin the fan by hand in both directions to check for noise. Then remove the drive belt and feel every bearing accessory by hand for play and noise.

Next look at belt alignment and condition. The fan at full lockup takes serious power at high RPM. A stretched or glazed belt although 'bad' is indicating other problems except if it is just old/high miles. Specifically is the tensioner the proper part number and has the correct spring tension? Any pulleys out of line?

I have had Communist China knock off tensioners sold at Autozone with weak springs. I figure they used the tension numbers for a later year (GM) that has the AC compressor after the tensioner. The older year, mine, has the compressor before the tensioner requiring the tensioner spring to deal with the AC compressor load before the crank pulley. It would sequel like crazy trying to get the AC going. I had to get a dealer part to solve the problem as the Autozone junk wouldn't.

Is the AC on during the noise episodes? Possible compressor locking up.

Good advise, I had installed a new tensioner, and that has been my initial suspect. I just changed fan belts and still have the noise, Fan and all acessories turn free. Belt seems to be tracking straight. I did double up clamps on all of the charge air boots. I think that I am going to replace the tensioner next.

 

[JJPage]

A little shot of aerosol hair spray on those boost hoses before sliding them into place works well, easier than trying to double clamp... I wonder if your CP3 could be producing the objectionable noise?

 

[WalterJ]

Good advise, I had installed a new tensioner, and that has been my initial suspect. I just changed fan belts and still have the noise, Fan and all acessories turn free. Belt seems to be tracking straight. I did double up clamps on all of the charge air boots. I think that I am going to replace the tensioner next.

My terrible under hood squeal was a new (8 month) NAPA Premium Gates belt, that proved to be too hard to run the flat side upon the fan & pump pulleys. No doubt it would last 100K miles, but my old, albeit softer, spare did the trick. It chirped loudly during shutdown; no over-running AC clutch. Alls quiet now. However...

thank goodness I had installed replacement Crank Vibration Damper p/n #ATI-917374, MANUF # 917374, o.d.=7.8", 3 O-Ring shell designed for easy "rebuilding/repair"; smaller than OEM Dia designed to permit changing serpentine belt without removing damper!

...and we found belt could not be removed past the tensioner pulley without loosening it substantially. What up with that? OEM tensioner replaced 2 yrs ago, so only replacements are goofy or OEM's too?

 

[promisedland]

Exhaust leak? The company i work for has a 6.4L ferd and we had squealing going on, after warming up at 10~ # boost.
Mani bolts where snapped.