97, 98 & 99 Noisy Fuel Pump

[ToolGuy]

Just got my newest issue of Corvette Fever and of course read it cover to cover. In the back there are tech questions for each generation and one in the C5 caught my eye. The person complained about their noisy fuel pump and what could be done. Of course I am aware of this and the noise does not mean the pump is failing but I do not like it myself. It is not an ungodly noise but still present. I was also aware there was a pad GM issued to silent this but every time I looked for the TSB I could not find it.

Well Corvette Fever recommened the following and I found it in the database:


#99-06-04-052: Left Fuel Tank to Underbody Contact/Rattle Noise (Install Foam Insulator Pad) - (Oct 21, 1999)

1.Raise the vehicle and suitably support.
2.Remove fuel tank shield from left fuel tank.
3.Support left fuel tank strap and tank assembly.
4.Remove fuel tank strap bolts. (I have no idea why it says this here because once the tank shield is off, the tank is free. There were no more bolts to remove)
5.Lower fuel tank strap and tank assembly to gain access between the front surface of the fuel tank assembly and the underbody, approximately 25*mm (1*in).
6.Remove the backing paper from the foam insulator pad, P/N 12493728.
7.With the wide side of the pad facing downward and the sticky side facing towards the tank, carefully slide the pad between the tank and the underbody. With the pad positioned centrally cross-car on the vertical face of the tank and approximately 50*mm (2 in) from the bottom surface of the tank, press on the pad securing it to the tank.
8.Raise the fuel tank strap and the tank assembly up into position and hand start the fuel tank strap bolts.
9.Tighten the fuel tank strap (should be shield not strap) bolts in the following order:
Tighten
Tighten the fuel tank strap bolts to 25*N·m (18*lb*ft).
*-* Front inboard bolt
*-* Middle inboard bolt
*-* Two outboard bolts

10. Install the fuel tank shield and hand start the attaching bolt and nut.
11. Tighten the fuel tank shield attaching bolt and nut.

Tighten
Tighten the attaching bolt and nut to 25*N·m (18*lb*ft).
12. Remove the supports and lower the vehicle.


I ordered the pad and after I install it I will report back to all on if it was worth it or not. A GM dealer friend of mine looked up the part for me first and then said he could sell it to me at his discount so I went ahead with it.

It normaly sells for the below:

Part Number 12493728
Opt P Description INSULATOR (03022-C)
Quantity Requested 1 ** NON-STOCKED **
Emergency Purchase
Special Order Pack Qty 1
Lost Sale 1
Book: Cost 12.90
Trade 16.97
List 22.63
Net Override Net N
Stocking Group* 4 GM - Special Order Default


Also note, I changed my fuel filter when I got my car and put my own piece of insulation inside the car a year ago simply by pushing the drivers seat back forward, pulling the carpet up from the rear water fall if you want to call it that and put the insulation there. Laid the carpet back down on top of it. Both seemed to help too.

[ToolGuy]

Got my part today... Was not what I expceted but what the hell I will try it! I guess I expected something larger, this is a 1/4 thick adhesive foam pad with a plastic clear cover on top, 8.5 x 10 in size.

UPDATE: I will need to make sure I have as little fuel in the driver tank as I can get since it drains last, so I do not have to deal with all the extra weight from fuel. And I also do not want to stress the fuel lines.

SO, it will be a few days or a couple of weeks before that happens! Stay tuned!

[ToolGuy]

UPDATE: I fianlly got around and low enough on fuel to do this job for those who care. : )

It took awhile to get the fuel down since I was not driving it much due to construction in my area.

Anyway, I did the job in my garage and you must get the car totally off the ground, all four wheels in the air. Next, remove the tank shield and whiggle the tank down 1 inch. You must also support the tank so it does not pull the lines too much. I used my floor jack and a block of wood. The pad goes on the front of the tank or the end that faces the engine.

RESULTS: It did make a difference... I did not hear it at all with a 1/4 tank of fuel. I than fueled up and I hear it a little bit. Now I know GM issued a new pump that is quieter but I am not going to that extent, not until my pump goes.

No reason to go on here unless someone wants more info...