Injection pump sound.

Should the injection pump on a 300 tdi run silent? I've been hearing a slight ticking that increases with revs whilst driving and it's been bugging me for the last two days. Today, I did the listening with the long screwdriver thing and found it quite alarming! It's incredible how much it magnifies every sound! Anyway, when placed against the injection pump, it sounded like it was ticking/knocking in time with the engine. When I placed the screwdriver against each injector, I heard exactly the same sound. (The vacuum pump wasn't making any ticking noise). I've had it where the injection pump really rattles and buzzes due fuel starvation but this is nowhere near as noisy. Under the bonnet, without the screwdriver, this is barely audible. But it's there! Is this slight ticking from the injection pump normal, or should it run silently?

I changed the fuel filter the day before yesterday and cleaned out the gauze filter in the lift pump at the same time. Fuel side looks OK. I do suspect I'm drawing in a little bit of air somewhere and I know that my sender unit is shot. I've got it bodged up with silicon at the moment. I'm going to replace that as soon as I can and I also want to bypass the sedimentor. Can someone tell me what's the best way to do this, (The search turns up varying ideas), and what bits I need, please?

Thanks.
Steve

The injection pump buzzes when air is running through,and this buzzing increases with revs.
Cannot normally hear mine unless air ingress(sounds a bit like a lot of ball bearings being shaken in a can)

Yes, I had that racket a few weeks ago when the filter in my lift pump got clogged up. This is nowhere near as noisy. Just wondered if the injection pumps make any sound at all when theyre running properly.

I bypassed my sedimentor last week or something, anyway what I did was cut the plastic pipes just before the unions so the ends are parallel and pointing toward the passenger side then use some 5/16" / 8mm rubber fuel hose in a 'U' shape. I stuck the ends of the hose in some recently boiled water to soften them so I could slide them on a good inch or so. Hose clips on too obviously (although at that point in the system its vacuum anyway). The reason I did it that way rather than cut the pipes further along so the hose is in a straight run, was ease of access, both when doing it then and out in a field or summink, plus it would be easier to see if I though it was leaking etc rather than tucked up along the chassis. Having said that, if I did it again I'd probably come up with a completely different idea anyway :lol:

Dan_Trials said:

I bypassed my sedimentor last week or something, anyway what I did was cut the plastic pipes just before the unions so the ends are parallel and pointing toward the passenger side then use some 5/16" / 8mm rubber fuel hose in a 'U' shape. I stuck the ends of the hose in some recently boiled water to soften them so I could slide them on a good inch or so. Hose clips on too obviously (although at that point in the system its vacuum anyway). The reason I did it that way rather than cut the pipes further along so the hose is in a straight run, was ease of access, both when doing it then and out in a field or summink, plus it would be easier to see if I though it was leaking etc rather than tucked up along the chassis. Having said that, if I did it again I'd probably come up with a completely different idea anyway :lol:

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So is the fuel pipe from sedimentor to sender and sedimentor to lift pump the same diameter? I thought I read that you need a 10mm to 8mm reducer?

Steviecops said:

So is the fuel pipe from sedimentor to sender and sedimentor to lift pump the same diameter? I thought I read that you need a 10mm to 8mm reducer?

Click to expand...

On mine it is the same diameter. I did find that the pipe out of the sedimentor has a hard plastic covering, I cut it back a couple of inches.

Cheers Dan.

No bother, glad to help.