Got an `98 mn6 26000k miles and the fuel pump has been whining since i got the car in dec last year.
The noise wasn`t so bad but yesterday started to get louder for about an hour than back to normal( little noise).
I know that `97 thru `00 have noisy fuel pumps but what does the noise mean?...is the fuel pump going bad ? and what makes the noise inside the pump?...bad bearing maybe?
And if i have to replace it how big of a job would that be?
Is fuel pump inside the tank? and if it is, does the tank need to come off?....my fuel gauge is erratic even with repeated Techron additive treatments....Can the fuel pump and fuel sending unit be replaced in one job?
Thanx

 

Seems as though I read a TSB from GM a few years back addressing this issue on earlier model Vettes. IIRC it only involved the addition of a sheet of sound deadening material in a certain spot on the front side of the driver's side fuel tank (where the fuel pump is located: and yes it's inside the tank).
Maybe others here can jump in with more info.
HTH,
Robert

 

ttt

 

ttt

 

My 01 Fuel Pump was whining a few months ago. I put fuel cleaner in the tank and now it has gone quiet.

 

I remember reading that there are two tanks with two pumps (one in each tank). When you are almost out of fuel it will switch to the reserve tank and that pump is louder than the primary pump for some reason. I think the primary tank is behind the driver and the secondary is behind the passenger seat.

 

Both tanks are used. There is only one fuel pump, which is located in the driver’s side tank. Fuel is constantly “drawn” from the passenger tank and dumped into the driver's side tank until it (the passenger tank) is empty. This is accomplished by using a siphoning setup accomplished with piping from the fuel pump (in the driver’s side tank). There is no reserve tank.

 

Whoever wrote what you read was wrong (surprise )

There are two tanks and two pumps (technically) and that part's right. The driver's side pump is the only one that is electrical. The pass. side pump is what is referred to as a "siphon jet pump". In other words it is a mechanical device with no moving parts that operates on a siphon principal and doesn't make any sound. It relies on the fuel (under pressure) coming from the elec. pump (driver's side) to do it's job and "pump" fuel.

Also, there is no "switching" between tanks. The elec pump supplies the engine at all times while simultaneously sending fuel to the right tank so the siphon pump can operate. The siphon pump, in turn, simultaneously sends it's fuel to the driver's tank so while you drive, the right side is always trying to "re-fill" the left tank. Since the driver's side (electric pump) is always supplying the engine, there is no need for any "switching" since, as stated, the driver's side has always been supplying fuel to the engine in the first place. The only electrical device located in the pass. tank is the fuel level sender.

It sounds more complicated than it really is but it is actually a rather simple, elegant and cost effective way of supplying fuel from two separate tanks. Kudos to GM for the design.

HTH

2blklt4: BTW, the fuel tank does not have to be dropped to change the fuel pump.

 

This is a bonus to our cars. even weight distribution of fuel in the two tanks.
It was interesting having a GM master Tech explain this to me once.

 

 

spiffy, it did sound kind of funny when I read the passenger side pump made more noise because I haven't ever heard it make more noise when it was running out of fuel but I've never really paid that much attention to it.