Water prevention in today’s diesel

mStrad

Member
Joined
Jul 16, 2021
Location
GA
TDI
1.9L TDI AHU
Hello. I would like to get everyone’s opinion if I should treat my fuel tank with a diesel fuel stabilizer that prevents water and slime accumulation in today’s ultra low sulfur diesel fuel. I have a 97 passat 1.9TDi that I usually only drive once a week so the fuel stays in the tank for quite a while. I’m already treating it with power service diesel kleen so I don’t want to over do anything. I’ve been reading about what ultra low sulfer diesel refinement has done to our diesel fuel today and I’m trying to combat these negative effects. Last thing I want is water and slime in my fuel system.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
I think you're doing enough. I also have a '97 Passat that I drive infrequently, and have never had a fuel issue.
 

n1das

TDIClub Enthusiast, Veteran Member
Joined
Jun 11, 2002
Location
Nashua, NH, USA
TDI
2014 BMW 535xd ///M-Sport, 2012 BMW X5 Xdrive35d, former 3x TDI owner
PS Diesel Kleen (silver bottle) doesn't do anything for water. PS DIesel Kleen is a summer only formula. That's why I absolutely will not use it.

What would be better to use is PowerService Diesel Fuel Supplement (white bottle) and use it year round. The white bottle stuff contains a solubilizer to help keep water completely dissolved so that it can pass harmlessly through the system. All diesel fuel contains a few ppm of dissolved water and this normally doesn't do any harm. It's when the ppm count gets high enough where dissolved water drops out of the fuel and coalesces into slugs of free water that's bad and absolutely must be avoided at ALL costs.

Free water in diesel fuel appears to be what's killing the HPFP in the CR TDIs instead of poor lubricity. The HPFP in CR diesels are much more susceptible to damage from water ingestion compared to older rotary injector pump diesels and the PD TDIs. Slugs of free water ingested by the HPFP will destroy it in no time at all. People often cite poor lubricity as the cause of failed HPFPs but overlook the importance of avoiding water in diesel fuel. Teardowns of failed HPFPs from CR TDIs have shown rust and corrosion inside which would be evidence of water ingestion had been occurring for some time. The same crap fuel will eventually destroy a rotary injector pump too.

I recommend keeping the tank FULL and topped off to prevent condensation from moisture in the air in the tank. Diesel fuel is hygroscopic like brake fluid is and will soak up moisture over time from air in the tank. Hot/cold temperature cycles will condense moisture from air in the tank on the walls in the air space above the fuel. It's best to keep the wall surface inside the tank buried in fuel instead of exposed to (moist) air. Whenever one of my cars won't be driven for a while, I always park the car with the tank totally full and topped off and with additive in the tank to prevent any possibility of soaking up water from condensation over time.

I recommend stop using PS Diesel Kleen (silver bottle) since it doesn't do anything for water and use only PS Diesel Fuel Supplement (white bottle) year round.
 
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mStrad

Member
Joined
Jul 16, 2021
Location
GA
TDI
1.9L TDI AHU
Thanks, but is it really necessary to do a water prevention treatment on every fill up? On PS website they recommended the fuel cleaning treatment ( white bottle) be done quarterly. Maybe I should just try Hotshots secret everyday diesel treatment?
 

n1das

TDIClub Enthusiast, Veteran Member
Joined
Jun 11, 2002
Location
Nashua, NH, USA
TDI
2014 BMW 535xd ///M-Sport, 2012 BMW X5 Xdrive35d, former 3x TDI owner
I'm not familiar with Hotshots at all.

How lucky do you feel? Play it safe by treating EVERY tankful with the PS Diesel Fuel Supplement (white bottle). Avoiding water is particularly important during winter months in cold areas due to condensation being more of a problem in winter. My priorities for an additive are to take care of any water I can't avoid getting and to increase lubricity. Providing anti-gel for winter use and increasing Cetane levels are of secondary concern.

Diesel owners often report gelling problems during the winter months in cold areas. And this is with properly winterized fuel too. People often mistake icing for gelling. They think they have gelling but actually have icing due to water from condensation. Properly winterized fuel won't gel at the coldest temps expected in a given region but icing due to water from condensation can cause problems long before that. Problems due to icing show up at temps cold enough for icing but still too warm for gelling. Avoiding water in diesel fuel will prevent these problems.

I fuel up ONLY at high diesel turnover stations along major routes that get a lot of heavy truck traffic to avoid getting water contaminated fuel. I go where the big rigs go to fuel up. Diesel fuel turnover is highest at these stations and is constantly being replaced, often daily, and will be the least likely to be contaminated with water from condensation and microbial growth due to water. I specifically avoid fueling up at stations that rarely get any diesel business. A single tank of water contaminated fuel from a low turnover station that rarely gets any truck traffic is all it takes to do a lot of damage in a very short time. Not worth the risk IMHO. I fuel up alongside the big rigs at truck stops and busy gas stations along major routes to avoid getting water contaminated fuel.

Water in diesel fuel absolutely must be avoided at ALL costs! :eek:
 
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Thunder Chicken

Veteran Member
Joined
Jul 19, 2012
Location
Sioux Lookout, Ontario
TDI
2012 Golf Wagon
I’ve been using the PS white bottle stuff year round, for years on all my diesels. Only once did I have gelling/icing issues and it was likely the odd time I’d forgot to have the bottle in the car with me. I never measure it, just give it a good glug or 2.
Funny, just recently had an issue with my tractor (also a hpfp common rail), thought I had ‘stuff’ growing in the fuel (low usage) and didn’t see mention of the additive being a biocide. So I drained the tank, replaced the fuel lines, found some slime in the water separator…. But what I really found in the tank was a piece of foil from the additive bottle’s lid. Was likely blocking the fuel intake line in the tank… oops!
Ill vouch for using the additive year round but keeping the foil out of the fuel :)
 
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