Hammer Drill in the Fuel Tank

[Aamp]

I've done a search and have found a few reasons that may have had an affect on this, but I don't understand how the fuel system works pertaining to the fuel pump.

I have a weird issue with my GTS N/A.

I don't drive this car daily anymore, and I had been driving it the other day maybe a week ago when I heard a 'buzzing' in the rear of the car. I payed it some mind, but soon forgot it had happened as it went away quickly.

Today I was coasting through a parking lot when it sounded like a hammer drill was going off in my trunk. WTF I thought!?

I drove home today and parked in my driveway when it re-occurred. Like a recip saw cutting my bumper off.

I shut the car off right away and it stopped. Then I thought I was going to have to start looking into this when it started happening with the car off!?!?

I jumped underneath and it was going for a long time, like 30 seconds. A hard buzzing around the diff area that made no sense. It stopped again, so I turned the car on and it started, stopped, started, stopped. About in 30 second intervals.

It must be with the fuel tank since it is the only electrical thing around there though I have not confirmed this yet.

Seeking help in determining what in the fuel pump region could cause this noise - even when the car has been shut off for a few minutes, it persists going from buzzing for a long time, to shorter periods of time on and off until it stops.

Here's the scoop.

My car currently has exactly 1/4 tank of gas as I have been EXTREMELY POOR lately. Uh oh.

I have replaced the fuel filter over a year ago with one from another nissan 300zx I believe? The filter had a 90 degree bend and I had to run extra hose - more restriction, more pressure? Excess Pressure being bled off?

Car runs and drives fine when it is warm.

50,000KMs.

Hesitation when cold unless I put my foot down a bit further which I don't like to do when the engine is less than op temp.

Ran the AC today, usually never do. Petro Can 91 octane all the time.

Have owned the car for 2.5 years with very little grief.

Runs smooth though idle wanders only a bit only sometimes; it will dip and flutter when idling at a light periodically, more so if it is cold out.

Fuel pump has always sounded a bit odd to me with a high pitch eee and if you tun the hazards on the eee pitch changes as they blink.

I have noticed that my car will start like a bag of crap like it is flooded if you switch the ignition to the on position before starting. I find a very quick and sudden go straight to the start gets best results and car starts like a champ.

Otherwise still running and driving very well.

Any advises would be absolutely great.

Remember, no turbos on my car, no hicas, no crap to make noise in the back except the pump.

Pump going on me? Pressure regulator thing? err uh hum what?

Any help would be appreciated

Thank you all very much!

[anthony]

the pressure regulator is up front on the intake,so id guess its your fuel pump
should be easy to check,its in the trunk under the mat , undo the bolts in the trunk and lift out your fuel pump, when it makes the sound again instead of looking under the car pop the trunk just to make sure it is your fuel pump before you start pulling your car apart

[Aamp]

This might cheer me up:

Peanut Butter Jelly Time -

OK, maybe not.

I am definitely going to inspect the pump as it is accessible from the inside of the trunk and does not require to drop the tank as it did with my old cars, but the sound is far more apparent from under the car than it is in the trunk hence the reason I would jump under right away to hear.

Dang darn diddly dong crap!

Sounded more from the passenger side furthest from the pump but sounds like it is coming from everywhere like the diff, and the shocks, and the tank, but the sound must be traveling through all these things.

But the big thing that puzzles the hell out of me is why the noise persists after the car has been shut off for over a minute to five minutes or so :?

Sounds like it is electrical in nature, but could be maybe like fuel pressure being bled back to the tank making noise like old water pipes making noise in a building.

When the pump is pumping, it still makes that old whine noise as it always had and this noise is additional. maybe a stuck check valve that needs to see pressure to open and opens and closes rapidly as pressurized gas builds up enough to escape?

This may sound incredibly dumb, but the fuel pump doesn't have a mechanism that assists in producing a flow around it if it is seeing heat, even if the car is off to cool it!? Safety features? Why it would do this with the car not running?

Has anyone had this problem before?

I vaguely recall my 300ZX doing this, and I thought it was that car that had this problem weeks ago, but this was definitely the R32 today.

[klys]

do you have HICAS?

if so could it be related to the actuator?

[Aamp]

No Hicas, just a GTS Sedan.

Update:

The sound can be more described as a screwdriver being shoved into a fan, or a stick in the spokes of bike wheels.

Took it for a drive 5 km to a gas station and gassed her up. Still driving well. Didn't make that noise again until I left a restaurant parking lot afterwards, then again at home. Seems not to make the noise while driving. This time the noises were much shorter lived and quieter sounding probably 'cause there is more gas in the tank.

Though maybe irrelevant, when I turned my headlights on today, the drivers one lit up only at first followed by the passenger one two whole seconds later.

Arrgh... Almost time to get the (insert your least favorite domestic vehicle brand name here) badging and apply it, ha ha.

Ohh I don't want any electrical problems!

Thanks for the helps so far.

[Aamp]

Damned Man

http://www.youtube.com/watch?v=bSzzTyXzKec&feature=related

Not my car but very similar sound. Pump must be on its way out, but still doesn't explain to me why it comes on while the car is parked and off.

[Skym]

That's the fuel pump priming before starting engine. I think some fuelpumps, like external fuel pumps are louder than intank pumps.

If you check the fuel pressure, it should tell you if the fuelpump is ok. There is 2 fuel filters, a sock filter on fuelpump, round looking fuelfilter in engine bay. Another area to check would be the voltage to the fuelpump.

How many km has the car done??? Fuelpumps should be changed every 100,000 kms. Fuelfilter every 20,000km.

From what I understand if fuel tank is run low all the time, it can damage a fuelpump, as I think fuelpump uses the fuel flowing through it to cool the pump.

This is a videoclip of a fuelpump that's on the way out -

http://www.youtube.com/watch?v=jjbYL9qI-SE

Or I gather a similar wacking sound -

http://www.youtube.com/watch?v=kGHSnQ_aMVY&feature=related

[G.T.R]

Best bet is to replace the fuel pump. if your in the ontario region I could even do it for you as I have a spare one off a GTS T lying around I swapped out for a walboro that I got for free. But let me know.
Steve

[Chris_RB]

I have an OEM one if you'd like to try/buy it.

Where do you live? If you're close to me thats an option as Steve suggested.

[Aamp]

Best bet is to replace the fuel pump. if your in the ontario region I could even do it for you as I have a spare one off a GTS T lying around I swapped out for a walboro that I got for free. But let me know.
Steve

I have an OEM one if you'd like to try/buy it.

Where do you live? If you're close to me thats an option as Steve suggested.

I am guessing Lower Rainland would be B.C.? I am also not in Ontario either. I am in Winnipeg, Manitoba, smack dab in the middle.

If anyone's be willing to ship, I'd be interested in what you'd be asking for one. You can send a PM if you'd like, as I would be interested, but I am very tight on $ right now so would probably have to hold off for a couple of weeks.

When I was living at home, it was easier to support this car, but at least I am not using it as my daily right now and can still use another car.

Thank you all for your help and support.