bwill03z

I started noticing a strong raw fuel smell on my cammed 2011 ls3 recently and realized today that the smell is coming from the driver side rear wheel well, or that general area. I previously thought it was coming from my exhaust and the car was running rich but it’s not. So is this most likely a fuel pump issue? I don’t know much about the location and how the fuel pump works so any info on what direction to go from here would be appreciated.

C5 Diag

Do you have a check engine light illuminated??…my advise to you is find an auto repair shop that has a smoke machine and let them pinpoint the leak that way…if not you’re only guessing and that can get expensive !!…also with a scan tool they can do an EVAP purge/seal drawing the EVAP system into a slight vacuum and see if that vacuum decays over time indicating you do have a leak somewhere.

bwill03z

No check engine lights and the car runs fine. How exactly would a smoke machine help my situation?

C5 Diag

If the tank were cracked somewhere or you can actually see a fuel seep or the top of the fuel pump housing were cracked you would see that with smoke…any part of the tank exposed to vacuum would manifest itself with a EVAP code…I believe a 0.010 leak or larger would be detected by the ECM…if you have a 0.010 drill bit that is very small !!

bwill03z

Oh ok I see what you’re saying

Also if it helps any on a diagnosis it seems like it only does it when I drive the car a pretty good distance or drive it hard to where the oil temp is above let’s say 210°. I’ve driven just a few miles out to town and back several times and never smelled it. Earlier today I drove it for a couple hours and the smell was as very strong around the rear wheel well.

Mr D.

Older thread from 2014 on this subject.

https://www.corvetteforum.com/forums...-recall-2.html

bwill03z

Just to follow up on this, I drove the car a good distance today starting out on half a tank of gas and never noticed the fuel smell. I’m going to fill it up and drive some more to see if it comes back. With this information does it still sound like it might be the cracked fuel pump fitting issue?

Quick Silver Z

I had this issue and had a negative smoke test. Turns out I overfilled the tank.

bwill03z

It’s possible I overfilled the tank but if that were the case shouldn’t the smell eventually go away?
I drove prob 60 miles today and never smelled it but again my tank was half full when I started. This first started back in mid March. Last week when I went on a short road trip I smelled it really strong. I did fill up before I left tho.

Quick Silver Z

My tech removed the driver's rear wheel and wheel well cover. He went up over the tank with his camera and saw no signs of any leakage. He said the "patina" was undisturbed.

I have made sure to stop filling the tank after the first click and the very strong gas smell has not returned.

bwill03z

The last two times I filled up and got the strong gas smell I didn’t fill it up anymore after it the automatic cut off. I drove the car all day today and never smelled fuel but I never got it over half a tank either. I’m going to fill up to about 3/4 full next time and see what happens

sirdano

mine was the elbow on top of fuel tank. Mine got so bad no matter full or all the way to empty. Also with windows up or down it smelled

Vate

Most likely it is the dreaded fuel pump elbow crack issue. If if stops when you go below half a tank, that's almost certainly the problem. The fuel pump needs to be replaced. If you have a manual transmission car, it is possible to do the job without dropping the rear end.

The C6 has two fuel tanks, one behind the driver and one behind the passenger, connected by a crossover pipe. The fuel pump is located in the driver's side tank. To replace the pump you have to drop the tank. This issue was common enough that GM had a recall for it (technically a 'special coverage adjustment') that would pay for the repair, but that's expired at this point.

There are a lot of threads on this topic. The best do-it-yourself thread is here. For a mechanic to do the work, expect to pay $2K+ for a manual transmission car, and $3K plus for an automatic.

bwill03z

Yep I’ve been reading all about it. I’m getting ready to order a new fuel pump and crossover lines. I have a manual trans and a local shop quoted me about $700 for labor so that’s not too bad. Wtf did they use plastic fittings on the pump is what I want to know!

Vate

I would have gladly paid $700 to have someone else do this job as it was rough. When I finally got the LH tank out, there was no solvent trail or any signs of fuel leakage but when I got everything back together (I got a new/used tank as well), it worked perfectly and I haven't had an issue since. I also have a 2011 manual (Grand Sport) and this is the replacement pump I used, which includes a whole new (and properly configured) sending unit.

bwill03z

Glad you got yours fixed, and yea I’m fine with $700, I was afraid it was going to be way more.
I looked at getting that Delphi pump also but on rock auto the stock AC Delco pump is only about $50 more. Wonder if there is any real difference