Easy Lubro Moly Diesel Purge How-To - with pics!!

silicone vacuum lines, FTW

Did this today, also changed the fuel filter. I did it a bit differently though, I didn't buy the fuel filter and vacuum fittings. Instead, for roughly the same price, I bought a second bottle of diesel purge and used that as a temporary fuel tank like so (after dumping the first bottle in the filter) :




image from http://flickr.com


Basically I filled the filter with diesel purge, disconnected the lines to the tank, attached tubing to those connections on the filter and ran them into a second bottle of diesel purge so it would be full strength (at least until that second bottle got sucked dry). Then hooked everything back up and drove it hard with the remaining diesel purge still in the filter.
Car runs much better, but honestly I think it was the filter (possibly long overdue). It ran smoothly before but now has more power.

I always find that the car runs so much better after a filter change.

But isn't the filter in backwards? Or is it on purpose?

My inline filter shows a flow direction such that the incoming flow encounters the outside of the enclosed filter media, where you can see any crud and where there is more room for it. This setup has the direction reversed.
Or have you done this on purpose because you expect any crud showing up to come after it's gone back to the bottle and and when it goes back again?

It is possible to do this with just pouring the diesel purge directly into the new fuel filter, and then leaving the engine to idle for 10-20 minutes?

jlav0330 said:

It is possible to do this with just pouring the diesel purge directly into the new fuel filter, and then leaving the engine to idle for 10-20 minutes?

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It will immediately get diluted by fuel.

OlyTDI said:

It will immediately get diluted by fuel.

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Really? And this is a process that you want for there to be no dilution and you consume as much of the diesel purge as possible?

When I change fuel filters in my rotary pump cars I prefill the filter with diesel purge. Although it does get diluted, it also gives the pump and injectors a shot of cleaner before that happens. I also try to do it with the fuel tank as low as possible. Although not as good as running the car directly on it for the entire can, it does help.

That's just good practice, I do the same. But to get the full benefit from Diesel Purge you must run it straight, allowing the unused portion to return to the container.

Agree completely.

And just to post more, if you fill that filter every 20k with DP it's unlikely you'll every need the DP service. If you have a really old or neglected vehicle it could help.

BobnOH said:

And just to post more, if you fill that filter every 20k with DP it's unlikely you'll every need the DP service. If you have a really old or neglected vehicle it could help.

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Just bought the car beginning of the year, 194k and not only do I not think the previous owner never did the diesel purge, I don't think the fuel filter's been changed for a while. Never mentioned it. He did, however, keep good care of the car and wrote down everything he did. Original owner too.

jlav0330 said:

Just bought the car beginning of the year, 194k and not only do I not think the previous owner never did the diesel purge, I don't think the fuel filter's been changed for a while. Never mentioned it. He did, however, keep good care of the car and wrote down everything he did. Original owner too.

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Did you get the timing belt history?
VERY important.
If it's not mentioned I would assume it never was and do it immediately!

If all the rollers, tensioner, and water pump are not documented those are likely to cause the belt to jump.

wonneber said:

Did you get the timing belt history?
VERY important.
If it's not mentioned I would assume it never was and do it immediately!
If all the rollers, tensioner, and water pump are not documented those are likely to cause the belt to jump.

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Yes it was all done at 150k, I'll make sure to have it done at 210k, y'all scare me with the horror stories of when this breaks (aka RIP TDI).

Yes, many cars have interference engines, bad news if belt fails. Plus on our TDIs we see a lot of previous jobs done partially or incorrectly.