C5 Fuel Pump "hum"
Thread Starter
Intermediate
Joined: Oct 2007
Posts: 38
Likes: 4
From: Cumming, Ga
C5 Fuel Pump "hum"
HELLO....
I'd appreciate information if you can offer some insight...
....i own a 2003 with 25,000 miles.....i bought it used at around 22,000 miles...i noticed a hum coming from the fuel pump...granted it was not a loud noise..but an annoying hum audible at slow speeds or in park...
...i asked 2 vette mechanics for opinions...one said he could replace the pump with a new one and it will probably make the same "noise"...the second mechanic said a new one would probably clear it up...although he didn't think the one in the car was about to crap out..
...oh well....several hundered dollars later and a new pump installed...it sounds almost like the old one....after a long drive...it gets a little louder...i feel like it is in fact perfectly normal.....but since i don't know any other c5 owners i'm hoping to learn from here....does yours hum?..
....thanks for reading this and have a good one....Mike
I'd appreciate information if you can offer some insight...
....i own a 2003 with 25,000 miles.....i bought it used at around 22,000 miles...i noticed a hum coming from the fuel pump...granted it was not a loud noise..but an annoying hum audible at slow speeds or in park...
...i asked 2 vette mechanics for opinions...one said he could replace the pump with a new one and it will probably make the same "noise"...the second mechanic said a new one would probably clear it up...although he didn't think the one in the car was about to crap out..
...oh well....several hundered dollars later and a new pump installed...it sounds almost like the old one....after a long drive...it gets a little louder...i feel like it is in fact perfectly normal.....but since i don't know any other c5 owners i'm hoping to learn from here....does yours hum?..
....thanks for reading this and have a good one....Mike
Tech Contributor
Joined: Oct 1999
Posts: 41,037
Likes: 9,801
From: Charlotte, NC (formerly Endicott, NY)
It is normal. The early C5s had a really loud fuel pump. A new design was made available in 99. It was much quieter but still loud. The pump is vey close to the passenger compartment thus it is very difficult to isolate the noise. In a standard car the pump would be several feet and several panels away from the occupants but in the C5 it is right behind the drivers butt with one thin panel separating it from the inside of the car. It is just a small sacrifice to gain better weight distribution and thus better handling.
Bill
Bill
Team Owner
Joined: Mar 2008
Posts: 24,310
Likes: 0
From: Canon City Co
St. Jude Donor '11,'13
"I voluntarily took 60 days off from OT"
Did you change your fuel filter while you were at it????...A plugged fuel filter will cause a pump to strain, resulting in noise.....and in time, it will cause the pump to fail....
Racer
Joined: Dec 2007
Posts: 413
Likes: 1
From: Simi Valley CA
Just one of the things a C5 owner has to live with. I keep my gas tanks full, don't notice at all. But, the lower the gas in the tanks the louder the sound. Just something I noticed over the years.
Greg
Greg
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Drifting
Joined: Jun 2004
Posts: 1,483
Likes: 0
From: St. louis, Missouri
that is the strainer. The external fuel filter is located on the inside frame rail , driver side. right around where the torquetube bolts to the tranny.After 04 all fuel filters are in the tank
Team Owner
Joined: Mar 2008
Posts: 24,310
Likes: 0
From: Canon City Co
St. Jude Donor '11,'13
"I voluntarily took 60 days off from OT"
True...2004s ARE in the tank....However, I recently worked on a friend's 2003 AE Coupe...it did NOT have an external filter (I know where they are)...All I can figure is it was a late production and the fuel filter had been relocated into the tank....My advice is if you have a 1997 thru 2002...you DO have an external fuel filter besides the strainer in the tank...and it should be replaced as part of periodic maintenance..(50K miles MAX).....If you have a 2003, you'd better get the car in the air and check for the external fuel filter....it may or may not have one...
Last edited by The NNIAL8R; May 6, 2008 at 11:59 AM.
Race Director
Joined: Nov 2003
Posts: 12,346
Likes: 5
From: Mustang OK
Partway through model year 2003 (beginning with 2003 VIN 35114929 produced on 11/25/02 so I've read), GM introduced the newly redesigned FFS fuel system on the C5. Later model year 2003 and all 2004 C5s have the redesigned FFS fuel system which was carried over to the C6. With this new design, the fuel filter was moved inside the left fuel tank and is part of the left fuel sender assembly. The left fuel sender assembly also includes a fuel level sensor, the fuel pump and reservoir assembly, the fuel pump strainer and the primary fuel pressure regulator. According to the 2003 GM Service Manual, the left fuel sender assembly is replaced as a complete unit and the tank has to be dropped to replace the sender unit assembly.
The following link contains more info on the redesigned FFS fuel system: 2003 - 2004: Service Information: Fuel Tank System
Burning Brakes
Joined: Oct 2004
Posts: 925
Likes: 4
From: EXTON PA
Fuel pump
HELLO....
I'd appreciate information if you can offer some insight...
....i own a 2003 with 25,000 miles.....i bought it used at around 22,000 miles...i noticed a hum coming from the fuel pump...granted it was not a loud noise..but an annoying hum audible at slow speeds or in park...
...i asked 2 vette mechanics for opinions...one said he could replace the pump with a new one and it will probably make the same "noise"...the second mechanic said a new one would probably clear it up...although he didn't think the one in the car was about to crap out..
...oh well....several hundered dollars later and a new pump installed...it sounds almost like the old one....after a long drive...it gets a little louder...i feel like it is in fact perfectly normal.....but since i don't know any other c5 owners i'm hoping to learn from here....does yours hum?..
....thanks for reading this and have a good one....Mike
I'd appreciate information if you can offer some insight...
....i own a 2003 with 25,000 miles.....i bought it used at around 22,000 miles...i noticed a hum coming from the fuel pump...granted it was not a loud noise..but an annoying hum audible at slow speeds or in park...
...i asked 2 vette mechanics for opinions...one said he could replace the pump with a new one and it will probably make the same "noise"...the second mechanic said a new one would probably clear it up...although he didn't think the one in the car was about to crap out..
...oh well....several hundered dollars later and a new pump installed...it sounds almost like the old one....after a long drive...it gets a little louder...i feel like it is in fact perfectly normal.....but since i don't know any other c5 owners i'm hoping to learn from here....does yours hum?..
....thanks for reading this and have a good one....Mike
Thread Starter
Intermediate
Joined: Oct 2007
Posts: 38
Likes: 4
From: Cumming, Ga
All Good Information.....thank You!
....thanks to everyone for the information....all good to know....the technical side is very helpful...i appreciate the time taken to reply...
....i've got my answer and then some.....take care...Mike
....i've got my answer and then some.....take care...Mike
Racer
Joined: Mar 2008
Posts: 323
Likes: 0
From: Warren Michigan
I have a 97 and wondered what that noise was. I posted a question a few months back because I noticed when I depressed the clutch or brakes (ie. putting a slight strain on the electrical system) the noise would hick-up and continue again. Everything that is here was posted on my topic too.
I have 23k miles on her so I haven't changed the fuel filter (yet).
I have 23k miles on her so I haven't changed the fuel filter (yet).
Race Director
Joined: Nov 2003
Posts: 12,346
Likes: 5
From: Mustang OK
See posts #7 and #12 above. From the discussion thus far, his car apparently has the newer, redesigned FFS fuel system. The fuel filter in the redesigned FFS fuel system is part of the left fuel sender assembly which also includes the fuel pump and reservoir assembly, etc. As the left fuel sender assembly is replaced as a complete unit, the filter also would have been replaced as part of this unit.