Vs Fuel Pump

[JoshSvc]

Driving to Sydney on the weekend it was rather warm and we were in stop start traffic, when all of a sudden there was vibration through the car and what i could only describe as a muffled warning buzzer going for a second then off for a second and back on, and the cars revs would drop up and down with the sound, To me it felt like it was coming from the fuel tank as it was a muffled noise and was sending a vibration through the car, only a small one but enough to be felt and the car would hesitate a little to take off.

Soooo i'm suspecting the fuel pump is on its way out so i'll replace that along with the fuel filter at the same time.

Any other suggestions for what it might be and is anyone interested in a how to?

[hako]

I'd be thinking more along the lines of an ignition miss causing the revs to drop low enough to make strange noises/vibrations. Try doing a fault codes check. The fuel pump usually will not make a noise when it fails....just stops. Did you happen to glance at the temp gauge? - if the car overheats in hot weather/stop start traffic, the warning buzzer will sound and the engine may hestitate.....

[JoshSvc]

It wasnt actually a warning buzzer, i was just trying to explain the sound, it was def coming from the fuel tank area as it just had the kind of sound u would expect from something contained in a fuel tank, was weird i have never heard anything like it before, when we stopped i turned the car off and restarted it and the noise went away but was still a little hesitant..... Weird

Never overheats.

i'll do a code check tomorrow and see what comes up

[hako]

OK....now that I come to think about it, I have heard a sort of buzzing sound from the tank after a long run on a hot day however that was when we lived in Townsville, now live in Toowoomba which is a lot cooler. At the time I though it was the FP failing but never did anything about it and it's still going OK. I suspect that on the hot day, with hot fuel etc, the FP possible was touching the fuel tank (inside the tank) and 'buzzing'. It could also be that the fuel was hot and basically 'boiling' making the FP suck air+fuel and making a strange noise. Petrol boils at about 95C but lower when under suction like when being drawn into the fuel pump so maybe that is why???
Our Commodore is at 260,000km...possibly a bit overdue for a new FP, but seeing as it is a bit of a hassle to change we have just let it go.

[JoshSvc]

I dont really want to change the pump, but seeing as i have no idea if its been previously done it would be a peace of mind to do it, we drive to Sydney abit from the Central Coast and the last thing i want is to be stuck on the F3 with a stuffed pump coz knowing my luck it will happen when i'm in a hurry lol

[RX25SE]

Replacing the fuel pump is cheap insurance, it is a common fault as these cars are getting older.
When I bought mine I replaced the pump and the crank sensor to prevent any hassles later on. Four years down the track and it's never let me down.

[wortus]

I dont really want to change the pump, but seeing as i have no idea if its been previously done it would be a peace of mind to do it, we drive to Sydney abit from the Central Coast and the last thing i want is to be stuck on the F3 with a stuffed pump coz knowing my luck it will happen when i'm in a hurry lol

It's not that expensive to do and fairly easy. Doing it on an almost empty tank or syphoning it first is a big help. Genuine fuel pumps are only around $100.00 and much cheaper than a tow as you can't really change them on the side of the freeway.

[JoshSvc]

Ok the car is bogging down now but will eventually run clean, still sounds fuel pump related?

[wortus]

Ok the car is bogging down now but will eventually run clean, still sounds fuel pump related?

If the pump is noisy I can't see what else it would be. Does the noise go away after the pump runs for a while, is the noise and issues witht eh motor running happening at the same time?
If you want to be sure go and have the fuel pressure tested. A friend had a VS V8 running bad and thought the pump was OK because there was flow but this is not the same as sufficient pressure being delivered by the pump. When my VN pump failed it was because one of the brushes in the motor had failed, the braid had broken off making the current go through the spring behind it and this must have been arcing which lead to a loss of continuity and no end of tapping the tank etc would get it to start and the car ended up needing a $250 tow. The only indication I got of a problem was the car was hard to start that day and idled bad for 30 or so seconds then ran fine, next time I went to start it no go and it had to get a tow.
I don't know how much a fuel pressure test would cost but it may well be around the same price as fitting a new pump yourself which when I did mine 2 years ago cost me just over $100 for a new genuine pump and cork gasket. If the tank is empty you can have the job done in less than an hour.
You just need to jack the car up onto stands or ramps baqck and front so it is level and let the diff drop down. Hardest part is getting the assembly out of the tank without breaking the float (you have to withdraw the float first and may have to rotate the assembly) and when putting it back in you have to rotate it, can't remember which direction sorry) to get it to sit back into the swirl pot. The other thing you have to be careful of is the return line which I think your car has connected to the fuel sender/pump assembly. If you pull the hose off the swirl pot it has to be reattached somehow.
I'd be syphoning the tank and not letting the fuel run out because it will effect the tar that is applied to the tank under the metal foil where the straps support it in the car and the fuel will bloat up the rubbers on the strap over time.

[JoshSvc]

Initially the noise happened when stopped at traffic lights, and only went away after we turned the car off and re started it. The noise hasn't returned but its been getting flat spots on acceleration and it will eventually run clean and not come back till its started up again. I have time tomorrow to get in and have a look so i'll be doing that and i'll post up what i find.

Cheers Josh

[JoshSvc]

Ok found the problem, its the transmission. Looks like there may be a split in the cooler leaking into the radiator. The tranny fluid was only just registering on the dipstick when hot and idling and there was a red/brown sludge in the radiator overflow bottle.