1999 Chevy Silverado Knocking

Tiny
PINUPPEET
  • MEMBER
  • 1999 CHEVROLET SILVERADO
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 150,000 MILES
I have a 99 Silverado that idles strange in drive. It is a knocking that�s coming from the engine I can make it go away by putting in fuel injector cleaner, but comes rite back on a new tank of gas. I am wondering if its not a pump problem. I will be doing the labor myself and want to be sure before I take the tank off and spend the money that it�s a likely fix. It was also suggested the mass flow sensor mite bee out.
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Friday, August 20th, 2010 AT 9:44 AM

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Tiny
WRENCHTECH
  • EXPERT
That engine has a known problem with carbon build up. Here is a TSB addressing the issue.

File In Section: 06 - Engine/Propulsion System

Bulletin No: 01-06-01-028A

Date: March, 2003

INFORMATION
Subject:
Engine Knock on Cold Start

Models:
1999-2002 Chevrolet and GMC C/K Pickup and Utility Models
2002 Cadillac Escalade (2WD)
with 4.8L, 5.3L or 6.0L Engine (VINS V, T, Z, U - RPOs LR4, LM7, L59, LQ4)

This bulletin is being revised to add an additional engine to the models section. Please discard Corporate Bulletin Number 01-06-01-028 (Section 06-Engine).

Some of the above vehicles may exhibit an engine knock noise that begins in the first 19,000-24,000 km (12,000-15,000 mi) of use. The knock noise is most often noticed during initial start-up and typically disappears within the first 5-30 seconds (may last longer in extreme cold temperatures). The noise is usually more noticeable on the initial start-up when the temperature is below 10 C (50 F) and may be more pronounced on the first cold start following a long trip.

This noise may be caused by an interaction between carbon that has formed on the piston, the piston motion and the cylinder wall. GM Powertrain Engineering, and an analysis of engines with this condition, has confirmed that the noise is not detrimental to the performance, reliability or durability of the engine.

THIS NOISE DOES NOT HAVE ANY EFFECT ON THE LONGEVITY OF ANY OF THE ENGINE COMPONENTS.
Important: At this time, attempts to repair this condition by replacing the engine assembly or pistons are not recommended.

Please share the information found in this bulletin with customers who inquire about this condition. In the event they have additional questions or concerns, please advise your Area Service Manager.
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Friday, August 20th, 2010 AT 10:12 AM
Tiny
MERLIN2021
  • EXPERT
Test the pressure, Autozone rents the tools for free(deposit), check our video:

http://www.2carpros.com/car_repair_video/test_fuel_injection_pressure.htm
Go here and checkout our video.
Also, while you are at the store, have them read the codes, post all found here.

http://www.2carpros.com/car_repair_video/test_fuel_injection_pressure.htm
Go here and checkout our video.
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Friday, August 20th, 2010 AT 10:12 AM

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