i can't find the source of a rattling sound that appears to be coming from the engine on the passenger side. it almost most sounds like rocks tumbling around in my glovebox. i hear it at low RPM's and low MPH. even in park, i will touch the accelerator lightly and will hear it again. it only seems to happen when i give it gas. i'm not really reving it, just a littel touch of the throttle. what could it be? <img border="0" alt="[bang head]" title="" src="graemlins/gr_banghead.gif" />
Location: Deep in the seedy underworld of Koonerville
Re: Rattling sound, source?
Oh My God!! <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> Someone else has heard that noise. My truck doesn't do it but, my dad's '99 2500HD does. It's only on initial acceleration from a stop at low rpm's. It sounds like rattling/water gurgling coming from the glovebox area. I was thinking maybe it was pinging from the back cylinders but, don't really think that's it. It sounds very similiar to pinging though. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
He can't hear it 'cause he don't hear so well....WHAT!! <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> but, it's there.
glad to hear that i'm not the only one. sometimes if i turn on the heat, i'll sometimes hear it then too. WTF!!!!! i wonder if you can hear it outside the cab? maybe if i pop the hood and rev it a little at the TB maybe i can find the source.
You have air trapped in your heater core. Common problem on these trucks. I have included the directions to purge the air from the cooling system.
Draining and Filling Cooling System
With a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.
When adding coolant, use DEX-COOLŽ coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner-at 50 000 km (30,000 mi) or 24 months.
The following notice applies to the 4.8L, 5.3L, and the 6.0L engines only.
DO NOT use cooling system seal tabs, or similar compounds, unless otherwise instructed. The use of cooling system seal tabs, or similar compounds, may restrict coolant flow through the passages of the cooling system or the engine components. Restricted coolant flow may cause engine overheating and/or damage to the cooling system or the engine components/assembly.
Drain and Fill Procedure
If you do not follow the procedure below, a low or high coolant level condition and/or vehicle damage could result.
Park the vehicle on a level surface.
Follow the steps below in order to remove the radiator surge tank fill cap:
Slowly rotate the cap counterclockwise.
Stop rotating and allow the hissing to stop.
After all hissing stops, continue turning counterclockwise in order to remove the cap.
Remove the drain hose from the left side of the radiator tank and repositon the hose to a catch pan.
Open the radiator drain ****.
Allow the system to drain completely.
Inspect the engine coolant:
Discolored -- follow the flush procedure below.
Normal in appearance -- Continue with the next step.
Close the radiator drain ****.
When filling the cooling system use a 50 to 60 percent concentration with DEX-COOLŽ coolant.
Fill the system through the radiator surge tank opening.
Pre-mix a 50 to 60 percent solution of DEX-COOLŽ and clean, drinkable water.
Slowly add the pre-mixed solution to the system until the level is slighlty above the surge tank split line.
Start the engine.
Idle the engine for 1 minute.
Loosely install the surge tank cap. Do not allow the system to build pressure.
Cycle the engine from idle to 3000 RPM in 30 seconds intervals until the engine coolant reaches 99°C (210°F) and the thermostat opens.
Shut off the engine.
Refer to step 3 in order to remove the radiator surge tank cap.
Start the engine.
Idle the engine for 1 minute. Fill the surge tank to ˝ inch above the COLD FULL mark on the radiator surge tank.
Install the radiator surge tank cap.
Cycle the RPM. Idle the engine to 3000 in 30 second intervals until the engine coolant reaches 99°C (210°F).
Shut off the engine.
Top off the coolant, as necessary, to ˝ inch above FULL COLD mark on the radiator surge tank.
Rinse away any excess coolant from the engine and the compartment.
Inspect the concentration of the coolant.
Do not use a chemical flush.
Block the drive wheels.
Place the transmission in park (P) or neutral (N).
Engage the parking brake.
Run the engine until the thermostat opens.
Stop the engine.
Follow the drain and fill procedure using only clean drinkable water. Repeat the procedure if necessary, until the fluid is nearly colorless. Refer to the drain and fill procedure.
Fill the cooling system. Refer to the drain and fill procedure.
1999 Chevy Silverado XC/SB Z71 - Comp Thumpr, Yellow LS6 Springs, 04 injectors, TR Pushrods, P&P Heads,Flexalite Fans, !Cats, !EGR, HPTuners, Thorleys, Borla Catback, Airaid, TCI 3000, Transgo w/ Vette Servo n Pinless Pistons, Tru-Cool, 18x9 Helo Ultras w/ 285/65/18 Nittos, Stainless Brake Lines, Hydroboost, Hawk pads, Ford Keys, exterior and interior mods, big stereo, less than 12,500 original miles.
2005 4wd Colorado (work truck)
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JSmith:
<strong> Guess what? I have that same noise too. I can't seem to find it but it only makes the noise on light acceleration and when it's cold. I just noticed it last Monday. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">tell you what, it is cold here all the time so mine has been driving me nuts this winter.