Cranking while Jumping Battery to Prime Fuel Pump

[Phyloader]

Hi Everyone,

I didn't see a general maintenance type forum anywhere so I just posted in here given my model.

If I set out to replace my fuel filter, but do not have a computer with VCDS or Vagcom that I could use to send a command to prime the pump, is there any downside to just hooking my car battery up to one of those jump boxes and cranking it until I've primed the fuel pump? What could go wrong other than my battery running out of charge ?

I once asked a auto mechanic about this and they said it would be fine; they literally said that is what they would do if I had them replace my fuel filter.

 

[oilhammer]

Slip the new element down into the housing, turn your key on, start the engine. Let it idle for 10 seconds. That whole prime the system deal isn't necessary with just a quick filter element change, unless it takes you an hour to swap it out.

 

[Phyloader]

Thanks! I'll make sure to seal the housing before I turn the ignition

When this is done, I've heard it's wise to look for bits of metal flakes in the filter housing as this can indicate if the fuel pump needs to be replaced. Any thoughts?

 

[borninabus]

certainly take a look at the top of the element and the bottom of the housing.
i even take a magnet around on any suspicious particles.
i drained the canister and cleaned it maybe 60k ago and nothing of note since.

i've done the fuel filter both with and without priming. the only time i've experienced trouble is when leaving too much air in the canister.

 

[Phyloader]

certainly take a look at the top of the element and the bottom of the housing.
i even take a magnet around on any suspicious particles.
i drained the canister and cleaned it maybe 60k ago and nothing of note since.

i've done the fuel filter both with and without priming. the only time i've experienced trouble is when leaving too much air in the canister.

If you drained and cleaned the canister how did you prime it? Did you run the priming cycle via VCDS or you just put the filter in, poured fuel into the canister, and then sealed it up?

 

[AverageAndy]

I've done both ways -filling with fuel to the top and just starting it (before having VCDS) -about 4 filter changes.
-filling with fuel to the top, then running output test to prime (after acquiring VCDS) -2 filter changes so far.

I did not notice a difference either way.

 

[Lotawood]

I took the canister out and cleaned it on the bench. On my wife's 2011 JSW.
I didn't have any diesel to pour in before buttoning it up.
No hoses removed.
3 output tests with VCDS. I could hear bubbles on the first 2 tests on an empty filter canister.

 

[borninabus]

If you drained and cleaned the canister how did you prime it? Did you run the priming cycle via VCDS or you just put the filter in, poured fuel into the canister, and then sealed it up?

i fill the canister with ATF before i seal it up.

 

[Phyloader]

i fill the canister with ATF before i seal it up.

WTH lol. You poured automatic transmission fluid into your fuel filter housing? I'm glad your engine burned through it without any problems.

 

[oilhammer]

A diesel will run on straight ATF, if it had to. New or used. Probably not the best for it, especially one with a DPF, but a swallow of it won't kill it.

 

[borninabus]

ha. its a fantastic cleaner!

not in my TDI, but i use it for engine flush in the oil too. add a quart and drive up to operating temp. freed up many-a sticky hydraulic lifter in flat 4 VWs using this technique.

agreed, maybe not the best idea in a DPF equipped car, but my ash load is something like 1/4 full with 80K on the warranty replacement DPF.

i have some diesel purge that i may fill the canister with next time if that makes you feel better