Bosch 044 petrol pump noise after 375 miles

[orsum]

In keeping with my planned ABY to RS2 conversion the petrol pump was the first thing I changed.

The old pump was very quiet

Before I upgraded the pump I found rust inside the tank, I had the petrol tank acid washed and treated, it looked like new inside when I collected it. I then fitted the new Bosch 044 pump and basket. I took my time making the pump fit perfectly. I also replaced the petrol filter.

That was about 375 miles ago.

At first I did not notice any noise from the pump when the car was at idle, there was a slight noise from the pump that appeared after about 50 miles of driving. After that it seemed like the noise has increased basically every time I have driven the car.

More recent the Hall sensor failed, I replaced the sensor and about three weeks later I collected the car to take it home.

As soon as I started the car I noticed the noise, the car has done about 375 miles since fitting the new parts and it’s now driving me mad. Something needs be done.

I have checked other threads on this issue and this is what I have done and am planning to do.

1 Filled the tank. It made no difference

Next will be

1 Pressure check
2 Delivery check
3 Open the tank and check the pump has not moved position and to see if it is touching anything. (In tank)
4 Replace petrol filter if all above are ok
5 Is there any sort of additive I could use to flush/clean anything that may have been left in the tank?

There ends my present knowledge level.

If I do not correct the noise issue I was thinking of the following.

Fit an original pump and take the 044 Bosch and put it in line outside the tank.

Does anybody have knowledge of this problem or a solution to getting rid of the noise?

[Rikki Kitto]

My 044 Bosch seems to make more noise than the original I'm guessing it's because of the higher flow speed but not to the point where it is annoying, always the possibility of a fake pump there's lots about🙁

[RichLV]

Mine is very audible from outside the car, at the rear arches. But I don't hear it from the inside. Though my pump is receiving 13 volts, that could make it more noisy.

[orsum]

The pump was purchased from Bosch so it should be an original.

Trouble is I have had it for about 2 year kept safe in the original packing waiting for the time to change it hence I cannot take it back, will have to buy another new one if it turns out to be the pump.

[mcandmar]

Coupe or avant? One thing to make sure is that the hose from the pump to tank cover is not resting against the side of the tank anywhere. Otherwise it will transmit the vibration into the tank and make a lot of noise.

[SteveH]

I have an 044 in my coupe and it's silent. I'd check all the pipes and wires are isolated from other components as already mentioned.

[orsum]

Coupe ABY 1996

[newsh]

My 044 has done about 70k miles, it's a little noisy when the tank is really low but always been the same

[macspring]

My genuine 044 pump didn't seem to make much noise on installation, but for the last couple of thousand miles it has been making an audible buzzing noise which is not 'really' audible inside the car, but certainly is when I drove it without the rear seat recently.

Mine is a saloon. My S2 Avant is similarly noisy with it's 044.

It is very audible outside both cars.

Yours could be 'normal'.

I had such grief putting in the second one that as mentioned a pipe 'could' be touching, but I am very reluctant to open it all up again.

[orsum]

Not a chance its normal. If it is then its coming out and another way to feed the system will have to be found and installed.

It was ok when first installed 375 miles ago now its just not acceptable.

I have every new part needed for my RS2 conversion waiting to go on but it will not happen with the noise the way it is.

The noise inside the car is that bad I will not even drive it.

Its just seems every step forward with this car seems to take me forever to get right, its very frustrating.

[Rikki Kitto]

They sure do test us but worth it all in the end, keep at it sure it will be something simple like mentioned make sure it's not touching anything it shouldn't

[macspring]

Its just seems every step forward with this car seems to take me forever to get right, its very frustrating.

I agree they can be trying, and yours is doing it's level 'best'.

Has to be someting 'simple'. Go through the posibilities logically using a paper check off list.

Possible causes -

1. A 'good looking' fake.
2. A faulty genuine one.
3. Wired correctly.
4. All rubber mounting bushes in place.
5. No pipes touching inside the tank.
6. .............?
7. .............?

If no joy run it on the 'bench' and see what you find.

A Walboro could be an alternative, but others will certainly know more than me.

Stick at it as you're nearly there, and an RS2+ spec will provide very rewarding driving.

[orsum]

Yep stick at it I agree.

No time available right now to check but I will post what I find.

[gnutz2]

This is a very common problem with bosch 044 pumps and it's a very installation specific problem. I used to run 2 bosch 044's but now I've changed to aeromotive 340 copy pumps because of this problem.

The noise you can hear is cavitation at the pump inlet and once it starts there's pretty much nothing you can do to reverse it.

Thing's to avoid are,

Restrictions to the pump inlet.

Hot fuel.

Low fuel pressure (this happens when motorway driving anyway).

Ethanol/methanol in fuel (most fuels have this in nowdays).

Another problem is on our high performance cars with upgraded fuel lines and relayed power to the pump only increases the fuel flow and compounds the cavitation problem.

[orsum]

Cavitation I would think could be caused by a blocked strainer basket?, restriction to the inlet as you said or a very low petrol level in the tank.

The petrol level has been checked and filled its not that.

A basket blockage is a big possible as the first time it ran it was fine, Lets say 30 - 60min later the noise started and has built up to unacceptable.

Now every time it starts it is loud.