Hi everyone,

I am new to this forum, but not to the experience...however, please forgive me if I do or say anything obviously butt-headed. I just posted this to pre-1997 forum as well, so sorry for the repeat if you are browsing forums.

I just bought a 1991 F150 w/300 c.i. v6 and auto tranny for weekend projects (running to home depot, etc) for $500. I changed the oil, filters, etc. but have driven it very little since I bought it a month ago. It starts right up and idles and drives great (especially for 192K on the odo). Not an eyesore either.

However, the other day I started it up and I noticed a sort of high pitched whine/whir coming from the backend (near the fuel tank). I suspect this is either the fuel pump going, or maybe a leak/airhole in the line or in the tank/pump itself?

I didn't pay too much attention until yesterday when I topped off the gas tank for the first time since owning it, and noticed a strong raw fuel smell while driving home.

When I got home there was fuel leaking from underneath somewhere; either from the tank, pump, line, I dunno. Anyone have any clue? Ever hear of this?

It was not whining before the other day, so I doubt it was something the previous owner knew about, but the fuel leak I'm not so sure about. Where would you start? I don't want to put too much into it as it is just a weekend runner.

Thanks for any help,
Don
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i had fuel leaking on my truck once while i was filling it up and the clamp that holds the tube onto the gas tank had loosened up... a few cranks to tighten it up stopped that... not sure if that helps or not but its worth a shot...

 

Ah, a cheap and easy fix would be nice...and right up my alley! I have to admit that I didn't get under there and really take a good look. With the whining noise I immediately assumed something more sinister was at fault. But I'll definitely take a look!

Thanks,
Don

 

Just guessing here but it's problably your fuel pump housing gasket leaking on top of your gas tank. That's problably why you can't see it. And it's more than likely air pressure from the gas tank making the hissing sound.

It's definatley not safe to drive! One backfire from your exhaust and it could explode! And if you smoke, don't throw any cigarette butts out the window! I'm saying this for your safety's sake. Drop your gas tank as soon as possible and look for the problem, or have a mechanic take a look at it. Just my opinion. Good luck.

 

I don't smoke, so no worries there! But thanks for the warning, and the suggestions guys. And I'm not planning on driving it until it is under control either.

I'm not sure if the fuel pump is in the top of the tank or if it is under-hood with a sending unit in the tank. And the Haynes manual I just bought couldn't be less clear. I'll have to climb under and get a better view.

But the whining started before the leak, and sounds mechanical, not hissing. I suspect I am dealing with two different issues; the whining noise and the leak. The leak I only noticed after filling up.

Somebody else mentioned that sometimes the top of the tank can get rust holes, so to fill only to 3/4 tank or so. A good idea to try for an interim solution I suppose.

At any rate, dropping the tank is probably a must. I bought a pump siphon from Pep Boys, that oughtta be fun with an 18gal tank.

Thanks for the help...and please post if anyone has any other thoughts!
Don

 

And how come no of you corrected me?? It's an inline 6! I'm in the wrong place! Well, thanks for accepting me, anyway But maybe now you will shun me! Eh, v6 or inline 6... we're all dissed by the v8's so what's the diff?!

Don

p.s. -- anyone know how I can change my login to a handle other than my full name? When I signed up I just filled in the required fields, I wasn't expecting my full name to show up... thanks for any help.

 

I'd email or PM the Webmaster and ask him politely if he would do a name change for you. Here's a link to his profile that you can use to contact him.
https://www.f150online.com/forums/members/1171-webmaster.html

 

Hey thanks for the help, Peacemaker. I just emailed the webmaster. And thanks to my handy-dandy siphon the cars have full tanks again! One more round and I can probably drop the tank. Best $2 I've spent in a while...the neighbors better not get on my bad side ok, just kidding... but there is this one little hoopdee that drives around with his bass thumping the paint off the walls that I would just love to burrrn!

later,
Don

 

Haha.. No prob man. Good luck with it.