# My first Diesel...Do you really need to change fuel filter every 20k?



## fritchdub (May 1, 2008)

Also, transmission fluid change every 40K? Is this really necessary?

2011 Jetta TDI

Thanks,


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## OttoSchultz (Apr 16, 2004)

If the High Pressure Fuel Pump (HPFP) grenades, it's around $8,000US after replacing all the affected parts. Fuel filter = $25-35.

New DSG = $3000-4000, parts & labor. The parts required for a DSG service are ~$120+ shipping.

You decide which you'd rather pay for.


If you want a car that you can neglect, buy a Honda or Toyota.


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## OttoSchultz (Apr 16, 2004)

But from a slightly more realistic viewpoint, a dirty fuel filter can rob you of power and fuel economy. If you live in a warm climate year-round, you could probably go 40k or 50k and never notice a problem. If you see temps of 25F or less, a dirty FF could cause some headaches. Have you educated yourself about Diesel fuel and cold weather yet?

DSG transmissions are quirky even off the showroom floor. if you went 50k or 60k between services, maybe nothing would happen. Maybe shift points would change or get harsh


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## Tinker Toy (Sep 13, 2005)

About the fuel filter....

I have wondered about the same thing too. I change my IDI fuel filter every 33,333 miles; easy to remember and the original pump is still good. The book says every 30,000 miles so I push it a little to get to the 33,333 easy to remember number.

A couple of filters back I took the old filter apart to take a look to see what was in it. It had only a little discoloration which I assumed was dirt but most of the filtration area looked clean and white. It seems that the fuel I was buying was mostly clean.

That may have been the luck of the draw and I am thinking that sometimes you might buy a dirty batch of fuel that will fill your filter with dirt. If you buy your fuel from the same few places as I am able to do and open up your old filters to see what you have in them and if they are mostly clean like mine was, asking about the need for 20,000 mile changes is indeed a good question. Unfortunately there seems to be no information on this but there should be. VW diesel fuel filters are expensive at $25 to $30 and the 20,000 mile change frequency detracts from the economy of running a diesel.

Another thing to keep in mind is that my car came with two water separators; one under the rear passenger seat and another as part of the fuel filter under the hood. Now we know that two were not needed and the one underneath is often removed as mine has been so it may be possible that VW was being conservative with the fuel filter change frequency as well.

I wonder the same thing about oil filters. I sometimes open up used oil filters and find no visible debris.

I realize that I have no answer for you but the question needs to be explored by more people and until more is learned, do it by the book is the safe answer.


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## OttoSchultz (Apr 16, 2004)

Your '86 IDI injection pump isn't producing 26,000+ PSI like in the OPs. A new/rebuilt injection pump is $500-1000 for your car, $8,000 for an '11 TDI.


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## joshzpunk (Oct 21, 2007)

you can never change your filters often enough. scrimping on a '11? I change my fuel filter every other oil change- 6k. sorry you got an auto. don't know much about them.


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## fritchdub (May 1, 2008)

Thanks everyone. I guess that was a stupid question. Why risk it? It just struck me odd, but really not a big deal. 

One more thing to ask (and maybe I need a new thread), but how easy is it to change the fuel filter. I just hate relying on mechanics. They charge you $20 for a simple part, then 1-2 hours labor at $100/hr.

Thanks again everyone!


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## burn_your_money (Oct 4, 2004)

joshzpunk said:


> you can never change your filters often enough.


I disagree. Every time you change a filter you open the system up to the possibility of contamination. Air filters are probably the most vulnerable but there is a risk with all filters.

I'm certainly not suggesting that you don't change your filters...


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## OttoSchultz (Apr 16, 2004)

fritchdub said:


> Thanks everyone. I guess that was a stupid question. Why risk it? It just struck me odd, but really not a big deal.
> 
> One more thing to ask (and maybe I need a new thread), but how easy is it to change the fuel filter. I just hate relying on mechanics. They charge you $20 for a simple part, then 1-2 hours labor at $100/hr.
> 
> Thanks again everyone!


I guess it depends on how mechanically inclined you are. For me, it's pretty simple and takes maybe 20 minutes, start to finish. For my brother it would be an all day project.

--You need a Torx bit to remove the screws from the lid (don't remember what size).
--Then the cover comes off, but it has a serious gasket so it takes some effort. The best way is to pry (gently) in one spot and work your way around. Don't get too enthusiastic though, there's Diesel right to the top so if you go too fast you can make a mess.
--The filter lifts out, but it fits in there pretty tightly so again, you may want to work your way around it, using a large flat screwdrive to pry it up. Two screwdrivers on opposite sides works best, IMO.

--Once the filter is out, I remove the canister which has 3 10mm bolts holding it in. I take it out to dump out the remaining fuel. I pour the contents into a clear glass jar to look for metal flakes, water, gunk, etc. I then dry it out with shop towls and re-install.

--Insert the new filter and carefully pour in some known clean fuel or PowerService. Then reinstall the gasket(s), and reinstall the lid.

--There's some debate as to whether "priming" is necessary, and how to do it. At 20k on my Jetta I didn't add anything to the filter housing. I cycled the key to ON about 50 times, started the engine, and it ran perfectly. At 40k, I poured in about 20oz of PowerService and cycled the key about 25 times. Again, it started and ran perfectly. Some people will argue that the lift pump doesn't run when cycling the key, but my theory is that after a certain number of "no-start key cycles" the pump does run to fill the system. If you have VCDS aka VagCom, or plan to buy it, you can use it to run the pumps and prime the system.


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## JSWTDI09 (Feb 22, 2009)

Do you really need to change the fuel filter every 20k miles. Let's just say that it is recommended. You could always just keep driving until it gets clogged and then tow you car in to replace it then. The idea of regular maintenance is to replace old parts before they fail and stop you dead in the middle of a trip. VWs respond well to regular maintenance and respond poorly to neglect. However, the choice is yours.

As for the DSG fluid change at 40k miles - the same applies (mostly). However, I have heard recently that VW is changing their recommendation to every 50k miles. I have not yet seen this in writing, but this is the current rumor.

Have Fun!

Don


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## vw tdi guy (Sep 26, 2007)

OttoSchultz said:


> If the High Pressure Fuel Pump (HPFP) grenades, it's around $8,000US after replacing all the affected parts. Fuel filter = $25-35.
> 
> New DSG = $3000-4000, parts & labor. The parts required for a DSG service are ~$120+ shipping.
> 
> ...




Vw really f u cked up on that one. No reason a pump should take out the whole damn fuel system. Bad design all around thats why I wont buy one.


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## Tinker Toy (Sep 13, 2005)

I will add that filters used longer than recommended do not suddenly begin to leak dirt. Some will even say that used filters work better than new filters. Also I have never seen an oil filter that was full of dirt. After following this site I have not heard of a plugged fuel filter except due to wax formation with #2 diesel in the cold of winter.

I have a paper cartridge filter in my shop vac; have reused it many times. It apparently works as well as it did when new as I don't see or smell it leaking dust. I clean it with compressed air as with auto air filters a time or two each.

We need more than dire warnings and fearmongering regarding filter changes but I don't know how to get more knowledge except to push the envelope a little at a time. I have 41,000 miles on my current fuel filter. I will change it soon, open it up and take a look.


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## THERAT (Mar 31, 2003)

*changing fuel filter*

I changed my fuel filter first time at 120,000 km then again at 180,000 I'm at 212,000 km now ... check YouTube for instructions and show and tell on how to change one out ...


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## Jaybles (Aug 3, 2008)

OP, I'm a VW tech, and i'll tell you from experience (along with the other people that have posted in here, im sure) that judging from some of the horror shows i've seen come in the shop at the dealership, the maintenance intervals VW has made are there for a reason and are one hell of a lot less expensive than what can happen if they arent followed :banghead: 
Honestly, the maintenance isnt that expensive or hard to do either. as said before, its something you can do at home in about a half hour or less with the right tools and a little know how (except for the DSG service. thats a little more complicated). 
I think VW actually did a pretty good job (generally) with their maintenance intervals. Not many people follow them after warranty stops covering it though  
it always amazes me that people buy a $22K + car, then dont spend the money to keep it in good running condition. 
My tdi has 140,000 miles on it and with the maintenance done at the recommended intervals it runs and feels like it just came off the factory floor. Take care of your car and it will take care of you 




vw tdi guy said:


> Vw really f u cked up on that one. No reason a pump should take out the whole damn fuel system. Bad design all around thats why I wont buy one.


 not the _whole_ system has to be replaced, but the majority of it does. 
it's more of a precaution than anything. just to make sure anything that would affect the new components gets out of the system. 
but its not only a VW that would happen to if the pump went 
any high pressure direct injection system will be at risk when metal shavings or debris gets in the system, hence the preventative maintenance. 




OttoSchultz said:


> --There's some debate as to whether "priming" is necessary, and how to do it.


 the priming isnt as necessary on the new CR diesels as it was on the PD or older styles. priming is really only used to get the air out of the lines so starting is easier after the filter has been replaced. The new diesels seem to have little trouble starting after the filter has been replaced though 
generally how I do it though is disconnect the fuel line on the outlet of the filter, then just use a $20 mighty vac hand pump until some fuel is drawn from the filter, then reconnect the line. works perfect every time 


Also OP, you might want to check out some of the forums on www.tdiclub.com. they have some really good info regarding maintenance specific to tdi's, along with a lot of other really helpful information. The people on that site really know their stuff, and will definitely help answer questions if you have any 
anyway, enjoy the car :thumbup:


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## Tinker Toy (Sep 13, 2005)

Jaybles said:


> OP, I'm a VW tech, and i'll tell you from experience (along with the other people that have posted in here, im sure) that judging from some of the horror shows i've seen come in the shop at the dealership, the maintenance intervals VW has made are there for a reason and are one hell of a lot less expensive than what can happen if they arent followed :banghead:
> Honestly, the maintenance isnt that expensive or hard to do either. as said before, its something you can do at home in about a half hour or less with the right tools and a little know how (except for the DSG service. thats a little more complicated).
> I think VW actually did a pretty good job (generally) with their maintenance intervals. Not many people follow them after warranty stops covering it though
> it always amazes me that people buy a $22K + car, then dont spend the money to keep it in good running condition.
> My tdi has 140,000 miles on it and with the maintenance done at the recommended intervals it runs and feels like it just came off the factory floor. Take care of your car and it will take care of you


 Your experience as stated has provided nothing that can be used to decide if VWs fuel filter change frequency is realistic or not. Take care of your car etc, is a nice slogan, however. 

Is it possible that VW engineers are pessimistic about the cleanliness of some of the world's diesel fuel supplies or are aware of the tendency of some people to neglect maintenance so they have overstated fuel filter change frequency to compensate? 

Can you, a VW Tech, take some used TDI fuel filters home to open up in your spare time to prepare yourself to make an informed answer regarding fuel filter change frequency?


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## Jaybles (Aug 3, 2008)

Tinker Toy said:


> Your experience as stated has provided nothing that can be used to decide if VWs fuel filter change frequency is realistic or not. Take care of your car etc, is a nice slogan, however.
> 
> Is it possible that VW engineers are pessimistic about the cleanliness of some of the world's diesel fuel supplies or are aware of the tendency of some people to neglect maintenance so they have overstated fuel filter change frequency to compensate?
> 
> Can you, a VW Tech, take some used TDI fuel filters home to open up in your spare time to prepare yourself to make an informed answer regarding fuel filter change frequency?


 
To a certain point, you are correct, the maintenance interval regarding the change of the fuel filter is not realistic because of how often it occurs. however, that would only remain true *IF, AND ONLY IF* the quality of the fuels the general public received were to an acceptable standard. Im sure you know though that the quality of diesel is not at all consistent, and, in my opinion, warrants the need for the change interval VW has provided. in all honesty, the interval in which the fuel filter needs to be changed varies from person to person because of this inconsistency in fuel. There's a thread on tdiclub regarding the quality of diesel fuel and it's lack of consistency. it's pretty interesting stuff. 
And I dont think the interval to change the filter is a reflection of peoples neglect towards their car at all. people who neglect their car are going to neglect it, regardless of what anyone says. 

The fuel filters on the CR tdi's dont need to taken apart to inspect them because what you're changing when you replace them is the filter element inside the filter housing, meaning they can be inspected upon removal. Judging by that, i'd say I can make a reasonably educated decision. 
Like i've said before, it really varies. There's no consistent interval. I've seen cars come in with 40,000 + since their last filter change and the filters look perfectly fine, almost brand new even. Then there are cars that come in with 5,000 miles on a filter that have a hard start, poor fuel economy, or other engine performance oriented complaint, and sure enough the fuel filter is in awful condition, with water and other contaminants everywhere. That is the reason why I think the interval VW has provided is a good, safe one. It may not be a reflection of the maximum mileage achievable on a filter, but there is a reason why its called *preventative* maintenance. This relates almost exactly to the whole oil change interval debate too; 
yeah, the oil you bought *can* last 25,000 miles, but you being able to reach that depends on a lot of factors: what are your driving habits, how was the engine broken in, what are your other maintenance habits, what quality fuel are you using, ect, ect. It is almost impossible to create an interval that satisfies every cars needs because they are all treated and driven so differently.


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## El Dobro (Nov 9, 2009)

You should follow the VW schedule at least until the warranty is up 'cause if there's any problems, you're going to need proof that you did what you did.


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## Tinker Toy (Sep 13, 2005)

Jaybles said:


> I've seen cars come in with 40,000 + since their last filter change and the filters look perfectly fine, almost brand new even. Then there are cars that come in with 5,000 miles on a filter that have a hard start, poor fuel economy, or other engine performance oriented complaint, and sure enough the fuel filter is in awful condition, with water and other contaminants everywhere.


 I assume that you are talking about diesel fuel filters as that has been the topic of interest on this thread and please correct me if I am wrong. 

Water in the diesel fuel filter is not a valid reason to change the fuel filter. Don't TDIs have a drain valve at the bottom of the fuel filter like my IDI filter? 

It is my understanding that gas and diesel refueling pumps at reputable stations have paper cartridge filters that filter fuel before it goes into your tank; probably not as fine as your and my diesel fuel filters but good enough to prevent a gross load of dirt. 

What, specifically were the contaminants that you mention? Were they algae or were they dirt? Were you able to ask the customer for clues about how the fuel filter could be in such awful condition when others that you had seen were not that way? 

A little additional enlightenment is needed for this topic and will be helpful to all I am sure.


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## OttoSchultz (Apr 16, 2004)

Jaybles said:


> I've seen cars come in with 40,000 + since their last filter change and the filters look perfectly fine, almost brand new even. Then there are cars that come in with 5,000 miles on a filter that have a hard start, poor fuel economy, or other engine performance oriented complaint, and sure enough the _*fuel filter *_is in awful condition, with water and other contaminants everywhere.





Tinker Toy said:


> I assume that you are talking about diesel fuel filters as that has been the topic of interest on this thread and please correct me if I am wrong.
> 
> Water in the diesel fuel filter is not a valid reason to change the fuel filter. *Don't TDIs have a drain valve at the bottom of the fuel filter like my IDI filter?*It is my understanding that gas and diesel refueling pumps at reputable stations have paper cartridge filters that filter fuel before it goes into your tank; probably not as fine as your and my diesel fuel filters but good enough to prevent a gross load of dirt.
> 
> ...


 Are you giving Jaybles a hard time because he's a tech? Unless it were sent to a lab for analysis, why would he know the "specific contaminents" in the fuel filter? 

I would say Jaybles is talking about fuel filters because that IS the topic in question in this thread. Fuel filters didn't come up randomly: *My first Diesel...Do you really need to change fuel filter every 20k?* 

Previous generation TDIs do indeed have a drain on the bottom of the fuel filter. The CR filters do *not* have a drain, so the only way to know if there's any water collected is to open the filter. Once you open it you need to replace the gaskets. 

Fuel station pumps do have inline filters, but are you really going to trust that they're getting changed at a reasonable interval? What about water buildup at the bottom of the storage tanks? If the tank goes low enough, you could get a slug of water through the pump. There was one example of that on TDIClub a while back.


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## Jaybles (Aug 3, 2008)

Tinker Toy said:


> I assume that you are talking about diesel fuel filters as that has been the topic of interest on this thread and please correct me if I am wrong.
> 
> Water in the diesel fuel filter is not a valid reason to change the fuel filter. Don't TDIs have a drain valve at the bottom of the fuel filter like my IDI filter?
> 
> ...


 
As I stated before,


Jaybles said:


> *The fuel filters on the CR tdi's *


 Yes I am talking about the fuel filters on the new diesels, IE the Common Rail diesels. 
as just previously said, no, they *do not* have a drain on the filter, so having water in the filter housing itself is a very valid concern, but you are correct, water in the filter doesnt warrant changing it, but it is a good idea to. Water in any portion of a TDI fuel system is a concern that needs to be addressed, which is why whenever I find water in the housing like that, I always take the housing out and empty and clean it. 

I really dont have any knowledge of what gas stations have for a setup, but I would imagine they would want to have some type of filter. however, I dont own a gas station, so i wouldnt know any information regarding what they use or how they maintain it. 

As stated above, it is impossible to know _exactly_ what the contaminates are without testing, but judging from the coloration, i'd say it was dirt contaminates. 
The dirt contaminates dont necessarily have to come right out of the gas station though. they can enter the tank from gathering around the filler neck, possibly when changing the filter, or if a small leak develops in the system. 
The only question we can really ask the customer is where they are buying their fuel from, and the majority of them say something along the lines of "anywhere I can get it". 
Even if they only bought fuel from one brand of station though it would be impossible to narrow it down to what fuel was causing the contamination in the filter because each station is independently owned and operated, so each station has been maintained differently. 



OttoSchultz said:


> Fuel station pumps do have inline filters, but are you really going to trust that they're getting changed at a reasonable interval? What about water buildup at the bottom of the storage tanks? If the tank goes low enough, you could get a slug of water through the pump. There was one example of that on TDIClub a while back.


 This is a perfect example of that. There are hundreds of factors that can affect quality of fuel at gas stations. You never know what can happen. It just comes down to too many variables. You can point fingers at what _may_ have caused it, but there just isnt a way to guarantee that the fuel going into your car is 100% perfectly clear of contaminates in the first place. Thats why my _*opinion*_ would be to follow the intervals as best as possible. This would almost certainly guarantee the proper operation of the vehicle for a very long time.


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## Tinker Toy (Sep 13, 2005)

Thanks for your reply Mr. Jaybles. I am surprised to hear that a common rail TDI does not have a water drain as part of the fuel filter. On the other hand, during the 30 years that we have owned three different diesel cars, the first being a 1981 Chevette diesel, I have never found water in the fuel filters nor did I find water in the under body water separator that is now removed that came with my new VW IDI in 1986. 

It might be worth mentioning that gasoline cars have a woven filter sock over the fuel intake inside the tank. It is possible that a VW diesel might have this as well which would keep larger dirt particles in the tank forever and out of the final filter under the hood. 

That makes two filters before the final fuel filter. 

Regarding needless worry about gas and diesel stations changing their filters in a timely manner, they had better do it or else fuel flow will be slowed and then customers will complain.


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## Tinker Toy (Sep 13, 2005)

OttoSchultz said:


> Are you giving Jaybles a hard time because he's a tech? Unless it were sent to a lab for analysis, why would he know the "specific contaminents" in the fuel filter


 I believe that it is important to identify the material that he has apparently seldomly found in a diesel fuel filter. If it is algae that slipped through the filter sock then that might not apply to those of us who live in cooler climates or buy fuel from reputable places with a reasonable product turnover and therefore not a valid reason to change fuel filters at 20,000 miles. If it was algae, then it is possible that Mr. Jaybles has not otherwise seen a grossly plugged fuel filter.


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## Jaybles (Aug 3, 2008)

Tinker Toy said:


> Thanks for your reply Mr. Jaybles. I am surprised to hear that a common rail TDI does not have a water drain as part of the fuel filter. On the other hand, during the 30 years that we have owned three different diesel cars, the first being a 1981 Chevette diesel, I have never found water in the fuel filters nor did I find water in the under body water separator that is now removed that came with my new VW IDI in 1986.
> 
> It might be worth mentioning that gasoline cars have a woven filter sock over the fuel intake inside the tank. It is possible that a VW diesel might have this as well which would keep larger dirt particles in the tank forever and out of the final filter under the hood.
> 
> ...


 
CR tdi's do have a water separator, however it is incorporated into the filter housing, and can be drained out when the fuel filter is serviced (the water collects in the bottom of the housing). 

I know the PD generation TDI's had an in tank fuel pump in conjunction with the high pressure pump that did have a filter similar to gas engines, but that is only designed for large particulates. 
I'm not sure the previous generations of TDI have the pickup filter, but I know they didnt have in tank pumps. 
The CR diesels have the in tank pump setup as well though. I remember seeing a filter on the pick up on a jetta wagon I had to remove it from because the owner filled up with gasoline :laugh: 
It's kind of hard to believe how many of those have come into the shop :sly: :facepalm: 




Tinker Toy said:


> I believe that it is important to identify the material that he has apparently seldomly found in a diesel fuel filter. If it is algae that slipped through the filter sock then that might not apply to those of us who live in cooler climates or buy fuel from reputable places with a reasonable product turnover and therefore not a valid reason to change fuel filters at 20,000 miles. If it was algae, then it is possible that Mr. Jaybles has not otherwise seen a grossly plugged fuel filter.


 You seem really adamant on pushing the amount of miles you can put on a filter. I would change the fuel filter well before it was "grossly clogged". If there was any kind of contaminate on my fuel filter I would change it. Regardless of the amount. I would rather spend the $10 and 20 minutes to guarantee that everything was ok. But I guess that's just me.


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## Tinker Toy (Sep 13, 2005)

Jaybles said:


> You seem really adamant on pushing the amount of miles you can put on a filter. I would rather spend the $10 and 20 minutes to guarantee that everything was ok. But I guess that's just me.



Mr. Jaybles, it's not for me but is for the OP as per his first question. VW TDI fuel filters are $25 to $35, not $10 and plus installation if you can't DIY.


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## Jaybles (Aug 3, 2008)

Tinker Toy said:


> Mr. Jaybles, it's not for me but is for the OP as per his first question. VW TDI fuel filters are $25 to $35, not $10 and plus installation if you can't DIY.


which is why I said _*I*_ would do that. The OP can make his own decision on what to do. 
also, GAP has fuel filters for $12.


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