Hummmmmmmmmm

[jlames]

Our 2006 625i Gator has been trouble-free which explains why our small ranch is all-green. Today, I went out to start it, I turned the key on and got a buzz or electrical humm that sounded like a fuel pump kicking on pre-start. It lasted for a couple of seconds and then stopped. BUT it came back on and stayed on when I started the engine. I looked through the service manual and can't find anything on it. NO wires are loose and the service manual I down loaded fro the Internet isn't very thorough. Any idea what it is? It'll go in to JD if I can't figure it out but we just got the tractor out and life's a little expensive right now for 2 JD visits in the same month!

[Dane]

I would suspect a master or starting solenoid. It's hard to imagine anything else that can make a click or buzz loud enough to be heard.

[GATORDONE]

The fuel pump is on a delay when turning the key on and pressure is met. The noise you are hearing on the pump will get noisier when the fuel filter starts to get plugged up because of starvation of fuel. Change the filters and that might cure your problem :Thmup:

[jlames]

Thanks, Dane. I went through that last night in the barn but no go. It was all good. Then, Gaterdone, I went inside and was looking for others on the web with the same problem and found a mountain of them, all pointing to what you said. So that's exactly what I'm going to try today. Logic told me then and you confirm today that starvation might be the problem so I'll let you all know how it comes out.

[jlames]

Officially the most difficult to work on vehicle I've ever had. Nothing like burying everything under and behind seats, plastic panels, metal bars and screwing things so close to the corners and edges the bolts and nuts are impossible to reach. Had a Big Block shoehorned into a little '64 Malibu that wasn't this tight.

[Dane]

Much of my 550 is covered in plastic panels. It's nice that JD used all #25 Torx screws so much can be done with just one tool until you get to one key panel where they threw in two #40 Torx just to make you curse, throw a wrench across the room and go digging through the tool box. The panel is not load bearing and there are other #25 screws close by so why they felt the need for those big screws in a plastic panel is beyond me.

[jlames]

Well, that didn't work. Talking to my local JDD mechanic who services both our 3520 and Gator, and looking at the exploded views, there's no in-tank filter; just the one bolted to the frame rail. Ordered one of those $19 replacements (AM117584) from JD but then found a cross reference one from Fram for $12 at Auto Zone. They'll cross reference the part no. on chat on the Auto Zone website but I'll post the part number tomorrow. The box is out in the barn. So the filter fit but not until after taking the little, white, plastic collars off. Lift the tabs up on the collars' sides and they slip right off. (No, not the red, plastic tip covers that keep it clean untill installed. Take them off too!) So next is the pressure regulator or fuel pump; depends on which is cheaper!

[GATORDONE]

You said this is a 2006 625i. In 2006 it will be a 620i, or 2011 on 625i, It makes a difference on the system.

[jlames]

Sorry. I misspoke. It is a 620i.

[Dane]

I see in one of your other posts you mention that your fuel pump is not shutting off? So, are you hearing it clicking away even when the engine is off and the key is in the off position?

[jlames]

Actually its clicking on with the key, runs for 5 seconds and shuts off. Then, when I start the engine, the fuel pump starts up again and stays running. Before this, I'd never heard it before which led me to believe the fuel filter was clogged and the injection system wasn't getting enough back pressure to click it off. Changing the filter didn't help. It still runs with the motor. I believe its an on-demand system that pumps until a certain pressure is reached and then stops until the pressure falls below a certain psi when it turns on again but I don't really know and I can't find any information on it.

[jlames]

No, it runs constantly after the engine starts. It comes on when the key in moved to its first position and then stops as if to say, "OK, I've reached pressure so I'll shut off". Then when I start the engine, it clicks back on again and stays running along with the engine.

[Dane]

So, have you confirmed that it is in fact the fuel pump making the hummmmmm? You say you hear the fuel pump clicking before starting the engine. A soft sounding tick, tick, tick is a normal type sound for a solenoid fuel pump. Does it get worse after starting?

[jlames]

Yes, it's the pump. It vibrates on the pre-start prime, stops then starts again with the engine. I suppose my only shot is to spent the $180 for another pump and hope that's it.I can't see any point in tearing the seats and paneling out when the diagram doesn't show a small filter in the tank.

[Skillet23]

Just cause it is easy to see on the 825i, is the fuel tank vent filter in good shape? Maybe the pump problem is pressure related do to the tank vent filter being plugged? Just a thought - I'm not even a decent shade tree mechanic, so I could be totally off...

David in TX

[jlames]

Yeah but you're trying and I really appreciate that. I'm pulling everything topside, seats, covers, everything and looking and both sides; pressure and delivery. If there's another filter in there, I'll find it; if not, I'll just replace the fuel pump and if that doesn't work, the pressure regulator. Ironically, that's exactly what my JD dealer mechanic would have to do so at least I'm not paying $65 an hour for the elbow grease!!!

[GATORDONE]

On later model 620i there is another small filter that could be in line before the fuel pump and is next to the seat frame.Yours might not have this. There also could be a callapsed fuel line from tank to pump, Also I have found pieces of rubber in the inlet of the fuel pump, you will have to take off to check out. Before spending the money for a fuel pump that your married to when you install it, Take a plastic pop bottle and put fuel in it and take a hose from it to fuel pump and see if the pump is quieter, This will let you know if it is in the Fuel lines or actually the pump.

[Destiny creek]

Yeah but you're trying and I really appreciate that. I'm pulling everything topside, seats, covers, everything and looking and both sides; pressure and delivery. If there's another filter in there, I'll find it; if not, I'll just replace the fuel pump and if that doesn't work, the pressure regulator. Ironically, that's exactly what my JD dealer mechanic would have to do so at least I'm not paying $65 an hour for the elbow grease!!!
I wish we could get work done at the dealer for $65 a hour up here its more like $125 plus 5% sales tax

[catalyst]

first let me say that i have an 855d ,not much in common with a 620i.
but just the same it doesn't cost anything to look.

Gator Offroad.com
click on Mod. Tips
areas requiring attn.
gas tank vent line fix.

good luck
Catalyst

[Dane]

Yea, the shop rate at my JD dealer is considerably than the aircraft mechanics at the airport. Go figure.

[jlames]

Me too!!!!!!!!!!!!!! My 172's A&P is nothing compared to my JD mechanic!!!!!!!!!!!!! As to the pop bottle... Great Idea. I'll try it tomorrow!

[jlames]

I'm sorry. I just have to thanks you again. I'm usually pretty smart thinking of things like that but not this time. Bypass the suspected filter to verify. Good thinking. It's great to have a resource like this forum with smart, logical people who care enough to help.