Issue: Underhood Whine or Rattle Noise - TSB #04-06-01-016A

[kdeatrick]

Document ID# 1563438
2004 Chevrolet Colorado Pickup

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Underhood Whine or Rattle Type Noise (Replace Tensioner) #04-06-01-016A - (Nov 9, 2004)

2004 Chevrolet Colorado
2004 GMC Canyon

with 3.5L L5 Engine (VIN 6 - RPO L52)

Built Prior To VIN Breakpoints 48123220 (Chevrolet) and 48123225 (GMC)

This bulletin is being updated to clarify the Correction and Parts Information. Please discard Corporate Bulletin Number 04-06-01-016 (Section 06 - Engine/Propulsion System).

Condition
Some customers may comment on a whine type noise and/or a possible rattle noise on light acceleration coming from the engine. This noise may seem more pronounced at start up after an overnight soak.

Cause
The source of the noise may be the balance shaft chain and the tensioner interaction. There are 2 balance shafts in this engine that are driven by the crankshaft to keep the engine running smoothly. This noise does vary from vehicle to vehicle and does not cause any durability concerns; however, some customers may find it objectionable.

Correction
A new tensioner has been designed to eliminate this noise. The kit consists of an oil fed tensioner, longer tensioner bolts, balance shaft drive chain and right side balance shaft assembly. Please note that it is necessary to install the updated balance shaft assembly because it contains an oil feed passage for the oil fed tensioner.

This new tensioner was introduced into production in the mid December time frame. If you have a vehicle built prior to VIN breakpoints 48123220 (Chevrolet) and 48123225 (GMC), install a new tensioner, P/N 89017543.

Follow the removal and installation instructions in SI for the Balance Shaft Chain Tensioner Replacement in the Engine Mechanical section. You will also need to order and install a new rear oil seal, P/N 12568124.

Parts Information
Part Number - Description - Qty

89017543 - Tensioner Kit, Hydraulic - 1
12568124 - Seal, Crankshaft Rear Oil - 1

Parts are currently available from GMSPO.

Warranty Information
For vehicles repaired under warranty, use:

Labor Operation - Description - Labor Time

J0787 - Tensioner And/Or Shoe, Timing Chain - Replace - Use Published Labor Operation Time

[jimz71]

hey kdeatrick, I have been having trouble getting my dealer to fix this both times over the summer they said it was nothing. Is this the actual buliten number the dealer would use?

[kdeatrick]

yes, it is from GM eSi.

[fsupoker]

I see it says If you have a vehicle built prior to VIN breakpoints 48123220 (Chevrolet).... so if mine goes like 48124999 then does this not apply to me???

[brinsmaid]

Interesting. I still would hesitate to associate this with the chirping sound I experienced before replacing the serpantine belt. When I say "chirp," think the Nextel sound, but rythmically repeated.

Thanks Kdeatrick!

[kodiakice06]

i have the chirp once in a while in the morning when i crank my truck up

[KCinMI]

Poker, correct, you would need a number lower than the one stated.

[superbeast]

my engine has a bit of a whine/loud hum on startup on occasion, not sure bout my vin number atm tho...its 12:20 am n' i dont wanna go out n' look