Fuel Pump making noise

[Brian 26]

Boat and engine model in signature.

I noticed it was taking some extra cranking to get my motor to start, the next day I heard a buzzing noise from the engine bay. On investigation it appeared the high pressure pump was making the noise and it felt hot to the touch - red arrow in my pic (unfortunately I don't know what the normal temp is). I pulled it off and there is nothing in the internal screen. I recently ran the boat out of gas while running it on the garden hose downhill (not sure if that maters). My plan is to replace it but thought I should check with you guys first. Is this the best course of action? I'm a little nervous about just throwing expensive parts at the problem.

Also bonus question, what is the valve with the blue arrow? I thought this was a pressure release valve so I pressed it, but liquid free flowed out of it. Water separator drain????

 

[Thalasso]

Normally it's the low pressure pump. Go to Harbor Freight and get yourself a pressure gauge and see what the low side is putting out. It just might be starving the high side. If i remember right the low side pressure should be around 11-15 lbs
One good thing is if your high side is going bad it can be bought separately where the low side cannot.

https://youtu.be/HFmxWzM9Dqk





Go by the numbers on the pump for replacement if needed. Not your engine.
Volvo Penta Exploded view / schematic Fuel System 5.0GXi ...

https://www.marinepartseurope.com/.../volvo-penta-explodedview-7744

 

[NoExcuses]

Judging by the symptoms I'd say you have paint problems. Only recourse I've seen is to replace the whole assembly and hope they changed the paint or try and clean it out.

http://forums.iboats.com/forum/engi...w-approach-to-the-volvo-penta-fuel-cell-5-0gi


If you want to test first use this guide

http://forums.iboats.com/forum/engi...ow-to-testing-your-boats-fuel-system?t=283269

 

[Brian 26]

Thanks for the info guys, I read/watched all of the links provided. I will be stopping at harbor freight on my way home from work. Here's hoping I can get this solved by Father's Day.

On a side note, there sure are a lot of fuel pump posts in this section right now.

 

[tgell001]

Thanks for the info guys, I read/watched all of the links provided. I will be stopping at harbor freight on my way home from work. Here's hoping I can get this solved by Father's Day.

On a side note, there sure are a lot of fuel pump posts in this section right now.

Yeah the one a few below this one is mine... same problem, its intermittent is what makes mine weird. Can I get that high pressure pump part number since the assembly twice as much. Also, i have the 8.1GXi, and all the pumps on ebay say they're only good up to 5.7Gxi but the look the same at a glance. Can someone confirm this will work? 5.7 P/N is 21608511 and VP says the one for mine is 21608512. Instinct says they're different but I've known VP to do some random stuff and it couldn't be a simple as a fitting thats different that i can take off the removed unit. just can't spot the difference and $649 vs $1049 is worth investigating.

 

[Brian 26]

I believe I have solved my issue - loose fuel filter. Please let me know your thoughts.

I hooked the outdrive to the garden house, low pressure side to a gauge and cycled the key a few times to prime the system. On turning the key to start it started immediately (like it usually does). The gauge read 6psi (keep in mind this is a cheap gauge). At this point I remembered I was going to check to see how tight the fuel filter was as I recently changed it and did not twist the new one down tight - I only recently read that this has to be very tight to prevent air leaks. I was able to get another 1/4 turn on it just using my hand. Fired it up again and the gauge read 6 then drifted to 5. I started and stopped it a few times always reading 5. High pressure side show 80-90 (the gauge bounces vigorously between those two marks).

I also pulled the fuel regulator and found minimal gray particles in the screen which I cleaned out.

My plan is to tighten it up further with a wrench and then take the boat to the lake on Friday for a water test.

Thanks again for the advice to buy a gauge and not just throw parts at it like I had planned.

 

[tgell001]

I pulled mine apart and the screens were clean(ish) but the bowl was FULL of bubbling paint and white scale. it did not come apart easily (i used a hammer). I used a wire brush and a pressure washer to removed any loosely adhered paint. Reassembled, and ran it on muffs in the yard and all seems well. I'm just assuming this will be an issue again and am prepared to throw a new one in. I'm actually just excited that I have the issue pinpointed and not just scratching my head spending money and time wrenching on it every day after work, not to mention multiple tow in's.

Strangely enough, the fuel cell i have is consistent with the ones in the 5.0 and 5.7 and not the part number for the 8.1's. So its cheaper and that makes me happy too

 

[Brian 26]

Unfortunately my saga still continues. I thought I had found the issue with the "loose" fuel filter but the buzzing noise came back after a few hours on the lake. I tested the low pressure side while out at sea under all load ranges and its very steady at 4psi.

My plan now is to rip the fuel pump assembly apart and look for debris and paint.

 

[Brian 26]

I think I finally have solved my issue (I know, I know, I've said that before...). NoExcuses nailed this right off the bat.

I ripped about the fuel assembly last night and was happy to find that the screen before the low pressure pump was approximately 75% filled with black paint flecks. I spent about 30 minutes with dental type tools, a pipe cleaner and carb cleaner removing all the paint I could get at. While the whole assembly is painted and does have some bubbling the real problem is the small passage way where the fuel leaves the spin off filter and goes in to the low pressure pump. And I have to think that the inside of the passage is not painted, only the inlet and outlet.

So with all of that clean I will be going to lake this weekend to test, I'm confident that I'll have better pressure, however more paint may come about and clog the screen again. In which case I may clean it again or just call it quits and order the new assembly. I will be adding a fuel pressure check to my list of yearly spring checks I run.

The fortunate thing is that I get a lot of warning through the high pressure pump making noise. In my driveway at 5 and 6 psi the pump is quiet, when I was on the lake and it started making noise I immediately tested it and found 4psi. So I think it's reasonable to assume at 4psi you'll start to starve the HP pump and it will let you know.

 

[Thalasso]

Have you checked for debris farther down the line? Like the regulator in the fuel rail?

 

[Brian 26]

Yes. The high pressure pump screen was clean, the regulator way over on the injector rail had some white particles that I brushed off with a rag.

Also it's worth mentioning, throughout my testing I never noticed a drop in performance, only the noise and longer cranking to get the motor started.

 

[Brian 26]

I'm happy to report I was out all day Saturday and half of Friday and did not have any issues.