odd noise - fuel pump?

[marcus1875]

Well an odd noise has started. On accelaration, 1st gear from idle, it squeaks. nothing when idling. on higher speeds it's like a low pitched burring/humming. only does it on acceleration.
Any ideas chaps?
Marcus

[gog440]

Is it defintely engine related? have you tried coasting and seeing if the noise is still the same?

[mrzigazaga]

Hi Mate..Doesnt sound like it would be the fuel pump..Im not sure you would hear it unless you were by the N/S rear wheel..If you have a hummimg/Burring noise then it sound more likely to be a rotational noise like Prop..Wheel bearings..Check the HUB nut..Half shafts..Susupension..Is there any vibration or shuddering that is even slight that you can feel inside the car?..Ziga

[marcus1875]

Doesnt do it on coasting. The car suspension has always squeaked a bit and still does. I'll check out the shafts tomorrow. I discounted them cause it only does it on acceleration, just started today after a 100 or so mile run. No harm in checking tho.
Marcus

[keatsie]

Can you hear the same noise when you switch the ignition on, the pump primes for about 20 seconds. For what it's worth, my fuel pump is extremely loud..

[wedgeinald]

Mine had a similar noise (which was only very transient - more a squeak, I was worried it was the water pump - until I got a wiring issue sorted) turned out to be too much slack in the fan belt (but only JUST too slack, now tightened and no squeal)

Does yours do it when you rev the engine with the car stationary?

[ElvisWedgely]

Exhaust knocking? Very common on V8's.

Tony. TCB.

[carob]

Not being wise of the 280 set up so could be 100% wrong here. Airflow meter, remove the hose and push the plate inside the AFM, that should kick the pump into life and could give you the noise you may be hearing.

What have you been tinkering with recently, before you heard the noise?

Rob

[RCK974X]

(I'm back from holiday...)

In my experience of 2.8i engines, the fuel pump tends to buzz, vibrate and squeal when on its last legs, and it's pretty much continuous, not related to pedal position. You can touch the pump when running (get an assistant to raise the metering flap, or unplug the connector) and it should be a gentle vibration, and perhaps a just audible whine.

[marcus1875]

Took the car into work this morning. Lo and behold..no noise! Until about 3 miles into the journey, when it started again, ever so faintly. Again only when accelerating. Didn't get a chance to open it up as the drive is through town, I'll have a blast this evening and update later.
It can't be the fan belt, got an electric one. Could be the AFM, I did have that off for the plenum and rocker cover change.
I just hope it's not the shafts, was looking forward to taking it in the RNR, and if it is those then i wont have a chance to fix it beforehand and I'll have to take the wifes "pressie"!
Marcus

[mrzigazaga]

Hi Marcus..Just check the tightness of the Hub nuts to be on the safe side..You could jack the front up and spin the wheels to see if you can hear any noises although wheel bearing can sometimes be deceiving, Jack up the rear and see if the wheels "rock" by grabbing it at 12 o'clock and 6..Pull the bottom and push the top in a rocking motion, If there is any play then it might be UJ's..They do become looser over time..Dont worry too much unless there is movement while driving..If you have grease nipples on the UJ's and prop have them pumped with grease.
Does the noise get louder the faster you go?..Cheers..Ziga

[wedgeinald]

marcus1875 said:

Took the car into work this morning. Lo and behold..no noise! Until about 3 miles into the journey, when it started again, ever so faintly. Again only when accelerating. Didn't get a chance to open it up as the drive is through town, I'll have a blast this evening and update later.
It can't be the fan belt, got an electric one. Could be the AFM, I did have that off for the plenum and rocker cover change.
I just hope it's not the shafts, was looking forward to taking it in the RNR, and if it is those then i wont have a chance to fix it beforehand and I'll have to take the wifes "pressie"!
Marcus

.....It can't be the fan belt, got an electric one.....

Even if you have an electric fan there will still be a belt for the alternator/power steering etc.

[marcus1875]

Well. Been out this afternoon. nothing. No noise. Runs fine, all nuts are fine, the alt belt is taught. bloody typical, never happens when you want it to.
Fingers crossed. I'll take it for another spin at the weekend and see what transpires.
Marcus

[marcus1875]

Well. the noise is sorted. wheel bearing! The bearing was the one i replaced last month. the bearing itself seemed ok. seems i missed a washer, put one in, the driveshaft seems to have better grip and no movement no noise. hope it works
marcus