I have some good friends that recently went on a road trip (Kris072)...

Car ends up at a shop for service ...

Tech tells them that C5's are having issues with fuel pump wires melting if you let the fuel level go below 1/4 tank in extreme heat (i.e. What we've had the last couple of weeks.)

Further info was, the fuel keeps the pump cool, hence it's location under/near the fuel tank(s).

Not sure if there is a difference for years ... Stage 1 or Stage II fuel delivery systems.

I didn't know this, but I thought I'd share with you all, just in case. Food for thought

 

Good to know! I'll keep her topped off in the heat.

Broham, what's this about heat that "you've" been having down there. It's been in the 80's down your way and it's been in the 100's up here.

You have'nt even broken a sweat yet down there.

 

boo hoo .. (closest thing avaliable to crying)

come to florida .. you get 100 degree heat + 80% humidity.


and that doesn't surprise as I found this out the hard way .. remember my water in fuel tank incident a few months ago .. they discovered my fuel pump burnt out when they tried to empty the tank .. i had 1/16th fuel (if that) and was on a road trip (cruising at speeds up and down (varying really .. ) ) .. it all makes sense now.

 

Timbo --- I saw 110 last Friday. I was waiting to see this guy ---> waiting at a bus stop. It's better today ... but Dayyyyumn last week ...

Neabs --- You can have FL bro ... been there, done that I lived on the East Coast for 11 yrs.

Yeah. They found out the hard was as well.

 

Nibs, you couldn't find this guy?
Yeah, you can have that humidity at least we have a dry heat.
Florida's a great place to visit though.

Sorry Dave, I guess the heat finally made it's way down there. We've had it up here for a couple weeks now. You get use to it.

Thanks again for the tip. I'll keep her fueled up in the Summer from now on.

 

Haven't heard of this happening before. Good info to know.

 

Thanks, but do you know the model year and build date of their car? The fuel system and pump were redesigned with installation of the new design beginning with the late model year 2003 cars. This new fuel system design is the one that was carried over to the C6.

BTW, love your sig pic.

 

Well, it's been in the tank a long time (fuel pump) In 1983 they first used an in tank pump. The fule serves as a really big heat sink! so it's best to make sure the pump is covered. now I believe it's about six inches long from the sock (pickup) to the end of the pump, so 1/4 tank should do it in a C5 tank as that would mean half of the left tank (thas where the electric pump is) that would cover it!

 

Yes, the fuel in the tank does provide a cooling effect for the pump. Mechanics have known this for a long time, for any car with in-tank fuel pumps. Considering how long in-tank pimps have been commonly used, It's surprising how many people do not know this.

It's generally not something that happens instantly after one time running low on fuel, but running on E all the time is known to shorten pump life in many modern vehicles.

I know many people who never run below 1/4 tank for this very reason. I usually fill mine at 1/4 tank too.

 

Yes, I realize that. But, it would be nice to know the model year and build date of their car and if one system is more prone to having problems than the other with the same amount of fuel left in the tank.

 

Nice info! I am going on a road trip starting the 7th of August. Okland,Ca. and back in 12 days. About 5500 miles. I will keep it above 1/4 tank... Thanks!!

 

or this guy He is crying too.

 

It's a 2003 MY Coupe and I'm sure the build date was in 2002, just not sure if it was after the Fuel System Upgrade in November 2002.

I followed them to North Carolina and filled up when they did and I had no problems. My build date is 12/02/02.

I have a real nice picture of Kris' Vette on the back of a flatbed heading to Chuck Hutton Chevrolet in Memphis TN. They really went all out to get the Vette back on the road in one day, great service.

In the interest of self-preservation I choose not to post that picture.

 

The build date is Jan 2003... and if you post that picture I'll tell them about your sheep !

(remember I know where you live and who you hang out with !!)

PS.. thanks Davey... I'm gonna try and get one of our techs to write up something to post for posterity..

 

Well here is what they did. they moved the fuel filter from the tunnel to the inside of the fuel tank.
It really wont affect the pump in any way. However if your filter plugs from a batch of dirty fuel............... it's a bear to change! (expensive)

 

Thanks for the tip Dave!

I was not aware of this, but it makes complete sense.....( read DOH!)

 

Ok..heres what happened.. we were in HOT/HUMID Memphis 5pmish..heavy traffic.. we were on reserve and heading for the hotel.
after checking in we went to start the car and move it. It started right up but when we put it in gear it died. Becuz we were on reserve it had gotten hot and shorted out the fuel pump which is located inside the fuel tank. There were 7 cars that had just gone thru the exact same driving conditions... all the same year cars.. We were the only ones who were on reserve.
I'll be posting a comment on the service we got in another thread.
After getting to our destination and talking to one of the certified mechanics in our group he gave us some of the technical info on this. The fuel in the tank keeps the pump cooled off so it was recommended we not let it get below 1/4 of a tank.
In order to change it you have to drop the tranny and the rear end.

 

Thanks for all the info Kris.

This is what makes this Forum THEEE best.

 

I'm not sure where you are getting your information, but the late model year 2003 fuel system redesign involved much more than just moving the fuel filter inside the fuel tank. My 2003 GM Service Manual contains very good descriptions that speak to how each (the old and the redesigned) system works and the differences in the two. The description of the earlier system is on page 6-1020 of my 2003 GM Service Manual under the heading Fuel System Description (without FFS). The description of the redesigned system is on page 6-1013 of my manual under Fuel System Description (with FFS). (I no longer have links to some of the articles that speak to these changes, but if I find any I'll pass them along.)

I'll mention just a few of the system design changes, but by no means is this all of them. The fuel pump/sender unit was totally redesigned. This redesigned pump/sender unit now inserts through the top of the left side fuel tank where the old unit was inserted into the side rear of the left tank. There also is one notable change included in the redesign that definitely should be mentioned here. This change was the cause of me asking the question about the model year and build date of the car above. I'll quote from my 2003 GM Service Manual where it speaks to the description of the redesigned system.

An assumption on my part would be that lower internal tank temperatures would also allow the redesigned fuel pump to also run cooler, but I have no way of knowing this for certain. This was the reason for my curiosity and questions above concerning the model year/build date of the car mentioned above.

Hope this helps.

 

Here ya go Gray