Engine/Transmission (1998.5 - 2002) Strange Harmonic type noise!

[Bobdrag]

Harmonic Noise!



Has anyone out there had this simular problem? This noise started at 25K, took it to the stealer and they test drove it with me. I thought I had a transmission or drive train problem, as it sounded like a out of round shaft rolling in a bearing and/or a bad bearing. The harmonic noise starts about 55-60 MPH or around 1600 tach in overdrive. With the slightest change in cruise control demand for less throttle, the noise stops. On the other hand as it requires more throttle like an upgrade, it increases in noise. Stealer told me that the transmisson and drive train were just fine. It was my VP44 setting up this harmonic and was normal as the VP gets broke in around 20K miles. At 30k I took to another stealer for their opinion. The first mech rode with me and said it was not the drive train or the VP44, he said it was my blower. He then took another mech along (transmission type)and came back telling me my torque converter was shoot! Well they rebuilt my transmission and the clutches were burnt on one side. Changed the converter, added a snap shift kit, and added an extra clutch disc to the pack seeing I pull a 5er. Still got the noise at 32K. Checked my LP pressure yesterday at the VP44, Idle 12. 5 # cruise 10. 0 # WOT 2. 0 #. Any help or suggestions would be appriciated.

Thanks!

Bob

 

[jGiacobbe]

Bob,



Any luck with the noise?



I have had the same problem since day 1. I've got 26K on it now. After reading through everything on here & talking to the dealer, I wonder if it might just be normal.



To me it sounds like the turbo. It only happens at certain RPMs and is definitely a direct relation to the effort the truck is working.



John

 

[Slightly Modified]

I had the same problem on my 99. I thought it was the exhaust at first, replaced it and still had it. I took it to the dealer to check the turbo, said everything was fine. I took it back in to the dealer a couple weeks later when I found a TSB on it, don't remember the number though. It described the noise perfectly, sounded like a whining noise coming from the turbo. Turned out to be a coolant fitting that screws into the block right above the exhaust manifold, cured my problem. Hope this helps you out.

 

[John Berger]

My truck had symptons like you are describing. I removed the orifice in the heater hose going into the engine and the noise went away. No problems with the heater, either. If it's not that it sounds like your exhaust or the turbo and probably is normal, as it occurs when you are working the engine.

 

[jGiacobbe]

So here's what I found in the TSB. Not the right year, but sounds exactly like it.



So... do you take the print into the dealer & tell them how to do their job? How do I tell them I think I found the problem... tactfully?



"A noise may be present which on initial investigation may sound like a noisy turbocharger bearing. The sound of the noise may be described as a whistle, a squeal, a howl, a moan, or a gurgle. The noise will be more noticeable as engine temperature increases. The noise will most often occur when the warm engine is operated between 1,500 and 2,200 rpm’s. The noise is usually heard in the cab, louder on the passenger side or seems to come form the dash vents. The noise may be caused by the coolant supply hose connector. The connector is located on the cylinder head next to the turbocharger. The connector is used to supply coolant to the heater hose. The bulletin describes the replacement of the hose connector. "

 

[CRSmith]

Does it sound like the noise "Airwolf" makes? My truck does that. Wonder if it's the coolant connector.

 

[Slightly Modified]

I left out the best part of my story. I took the truck back in with a printout of the TSB and told them I thought this might cure the problem and they said they would perform the TSB. Well two hours later the service writer calls me over and says that they crimped off the hose going to the connector and test drove it and could still hear the whining/whistle noise, said it was especially loud coming from the tailpipe. Said I might need a new turbo. I told him the whistle coming from the tailpipe is normal since I have a walker muffler and a four inch system. After I heard that I knew I didn't want them working on my truck since they didn't even know what they were listening for anyway. If I were you I would do like I did and save yourself the headache and go to the dealer and buy the part, only costs eight dollars and replace it yourself and see if it cures the problem. If it doesn't your only out eight bucks. Good luck.

 

[John Berger]

On the 99's there was a gasket/washer type piece in the hose fitting. It had a small orifice. I just removed that and re-connected the hose and fitting. No more noise.