loud constant hum from fuel pump.

[zitty2016]

I have a 91 vanagon, I'm getting a loud constant hum from the fuel pump. Is this something I can ignore, fix easily, or do I need to replace it?

[Igeo]

Start with replacing the fuel filter and see if that improves the mood of the pump.
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1987 Westfalia 2.1 WBX Manual

[zitty2016]

sounds good, thanks

[DuncanS]

Had this recently and it was water in the tank. Add a couple of drygas units and see what happens. If you haven't replaced the expansion tank tubing or roll-over valves recently, this could cause the water to get in.

And yes, the filter as Igeo suggested. My super Vanagon mechanic said don't buy a Bosch fuel pump. Noname after market units are better according to him.

Duncan

[zitty2016]

ok, thanks

[DanHoug]

i've noticed the hum in my Bosch pump gets louder with increasing ambient/fuel temps. after many hours of driving in 85F+ weather, my pump got louder. didn't reach under to feel the tank but i would imagine that with the considerable quantity returned from the fuel pressure regulator, hoses nicely warmed a top the engine, that the tank temp was above ambient.

with lubricity an inverse function of temperature on petroleum fuels, more noise at higher temps makes some sense.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[CanStan]

Pinch off the line from the tank to the pump. Remove that line from the pump, and swap the power and ground wires around on the pump (easy if they are spade terminals, a little more of a hassle if they have ring terminals). Hold a clear bottle / jug / container up to the pump and have a helper turn the key forward 1 click. Not to start it, but just to turn the power on. This will prime the pump 2 times, and push some fuel out of the pump. There's probably enough fuel in the lines to do this 2-3 times, by switching the key back off, then forward again.
Now check your bottle and see how much rust / crap / dirt flushed out that was caught in the built in screen of the pump. This should give you an idea of the condition of your tank. Put the line back to your fuel pump, swap the power and ground wires back to their proper spots, and go for a drive. If the pump noise is gone, carry on and happy Vanning. If it returns at some point, back flush it again.
I once had a Van that had to be flushed about every 2000 miles. Over the course of a year, it progressively got worse until it was every 100 miles. I swapped out the rusty crusty fuel tank, and the problem was solved.
Good luck!

[AtlasShrugged]

I have a 91 that suffered with a noisy fuel pump..for years.

Do change your fuel filter, especially if you do not know when it was last changed.

Most fuels have ethanol these days, so water in the fuel tank should not be an issue. You can use some dry-gas but it wont make any difference.

I installed a new made in Czechoslovakia Bosch fuel pump. ..still noisy. Now it was even worse, especially when it was hot.

Then two years later the Vanagon died going down the road. After some checking..my new fuel pump was dead.

So..went to eBay and got a $50 fuel pump. Surprise! Absolutely silent! Works just fine since March 2019. Unbelievable.

Lesson learned. Bosch quality is very poor these days..
https://www.ebay.com/itm/321874536438

[dobryan]

[zitty2016]

Just a follow up. I added 2cans of heet to the gas as well as 5 gallons of fresh gas-no difference. I then replaced the fuel pump and filter-no difference. 3 years ago I resealed the gas tank and it was in very good condition-no rust or debris in the tank. Not sure where to go from here.

[Wildthings]

Maybe blow back through the outlet of the tank with compressed air and see if that eliminates the noise. Loosen the gas cap before doing this so you don't pressurize the tank.

[4Gears4Tires]

[zitty2016]

The pump is attached above and below by two rubber bushings with a stud through the bushings.

[Wildthings]

FI cleaner might clean up the outlet screen a bit.

[dgbeatty]

What is the part number on the pump. A picture would be helpful!
Now for the details.
What is the measured fuel pressure and more importantly the 30 second measured flow amount from the return line, post regulator.

On going research project to defininantly identify the root cause.
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