Replaced fuel filter, I am an idiot

Lange17

Member
Joined
Jun 6, 2022
Location
North Carolina
TDI
2014 Passat SEL
I just recently (yesterday) replaced the timing belt and water pump due to a coolant leak. I figured while I was in there I should replace the fuel filter since it hasn’t been done since I’ve owned the car (currently at 80k). However, I didn’t read how to replace the fuel filter and since I’ve never owned a diesel before I did it wrong. I removed the old filter, the whole housing actually, and cleaned out all the sediments. Once the priority service (t-belt/water pump) was done I threw a new filter in and bolted everything back up. An important note is that I did not put any fuel or any liquid in the canister at all. It was completely dry. I then primed the fuel system for a few minutes but turning the car on without starting the engine. Once I tried to start the engine, it was run for a second and immediately die. I then repeated the previous step for a few more minutes and same thing. After a few attempts at this spanning 20 minutes or so the engine finally started. No engine lights or warning indicators at all. In fact, I let it run for about 30 minutes while I made sure the coolant level was correct. After I shut the engine off to put some trim back on, I tried to start the car to move it out of the spot. Same thing as before. After I got it running (a few minutes later) I drove about 30 minutes with no issues at all. Now I parked the car and tried to start it and the same thing happened again! I figured the system has to be primed at this point since it has over an hour of run time.
What is going on? Is it somehow losing its prime over time? Maybe an air pocket?
What can I do to fix this issue? Rest assured, next fuel filter replacement will come with more care and attention.
 

pedroYUL

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Sep 8, 2011
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MI, USA
TDI
2004 wagon BEW; 2015 Passat CVCA; 2015 GSW CRUA
You need VCDS or OBDeleven to really prime the fuel system
 

pedroYUL

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Sep 8, 2011
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MI, USA
TDI
2004 wagon BEW; 2015 Passat CVCA; 2015 GSW CRUA
No idea on that scanner, but it needs to be able to command the electric fuel pump. You need todo that some 10min or so, to eliminate air in the system
 

Lange17

Member
Joined
Jun 6, 2022
Location
North Carolina
TDI
2014 Passat SEL
Okay. I’ll bring it tomorrow and take a look. That’s all it’ll take to stop this from happening every morning?
 

gforce1108

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Aug 2, 2006
Location
Newburgh, NY
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04 Jetta GLS BEW, 14 Audi A7 V6 TDI
Air though the hpfp is very bad. Stop running it until you have it sorted. Recheck that you have the filter and hoses installed properly. Once primed, regardless of how it was done (key cycle does not cycle the pumps), it should stay primed.
 

turbobrick240

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Nov 18, 2014
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maine
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2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
Sounds like you're losing prime. I'd check all of the hose connections to make sure they're right and tight. You could also check and top off the canister if needed.
 

IndigoBlueWagon

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It's common to over-tighten the bolts that hold the top on the canister. Beware of doing that. If you do you can stip out the bolts or the threads in the canister and you'll lose prime.
 

pedroYUL

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TDI
2004 wagon BEW; 2015 Passat CVCA; 2015 GSW CRUA
You know how many times you have to cycle the key to fill the whole filter canister from dry?...many many many times. I bet money there are still air pockets there
 

Lange17

Member
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Jun 6, 2022
Location
North Carolina
TDI
2014 Passat SEL
I just checked all the hoses and everything is connected just as they were from factory. I couldn’t check the canister bolts right now but every thing else looks good. I don’t think I’ve over tightened the canister but I can’t tell right now. I just tried to start it and same thing, starts and immediately dies. Once I get my torx I’ll take a look at the canister
 

Tom in PT

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2005 Passat sedan - SOLD; 2013 Passat DSG; both purchased new
Suggestion: remove the top of the cannister and slowly fill the canister completely to the brim with fresh clean fuel. Replace lid. Cycle the key four or five times. Then start the engine.

I have changed fuel filters this way on my '05, and '13 VWs and many other diesels and never had an issue with air. Did not use VCDS either. Undoubtedly you still have some air in the system.
 

Mongler98

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COLORADO (SE of Denver)
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98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Suggestion: remove the top of the cannister and slowly fill the canister completely to the brim with fresh clean fuel. Replace lid. Cycle the key four or five times. Then start the engine.

I have changed fuel filters this way on my '05, and '13 VWs and many other diesels and never had an issue with air. Did not use VCDS either. Undoubtedly you still have some air in the system.
DO NOT DO THAT.
never ever fill a filter with anything other than fuel from the tank via a vacuum though the filter.
Same goes for oil filters too. install them dry.
never take advice that goes against procedures
 

Lange17

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Jun 6, 2022
Location
North Carolina
TDI
2014 Passat SEL
I put everything back together and primed the system for about 10 minutes just turning the ignition on over and over again and got it to start. Then when I shut the engine off and does the same thing. Starts and immediately dies. Also, probably unrelated, but the passenger drl goes out when this happens and comes back when the engine starts running.
 

Lightflyer1

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2015 Beetle tdi dsg
If you are going to work on the car you should get the manuals for it. Nothing like having the instructions!


Buy a one day subscription and you can download everything they have for 24 hours. Read up here about it as it can be a little overwhelming and you want to get and organize everything. Not to mention getting the VCDS tool as well. You can't beat this tool for showing the codes for your VW and performing maintenance tasks that this kind of tool is needed.

 

Lange17

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Jun 6, 2022
Location
North Carolina
TDI
2014 Passat SEL
Update:
I scanned the car and found a P001600 code present.
After a bit of research, it looks like it may be timing after all. Possibly fuel pump out of time.
 

Lightflyer1

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2015 Beetle tdi dsg
Did you use the proper tools, parts and procedure when you did the timing belt? Sounds like you didn't if it is out of time. You now need to check and make sure the pistons didn't hit the valves and damage them. You will also need VCDS to check and set timing.
 

Lange17

Member
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Jun 6, 2022
Location
North Carolina
TDI
2014 Passat SEL
Did you use the proper tools, parts and procedure when you did the timing belt? Sounds like you didn't if it is out of time. You now need to check and make sure the pistons didn't hit the valves and damage them. You will also need VCDS to check and set timing.
I made sure the cam and crank were in sync but I didn’t think about the fuel pump. This is my first diesel and I wasn’t prepared to say the least. I don’t think the engine suffered any damage since it runs great once it actually starts.
 

Lightflyer1

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2015 Beetle tdi dsg
Some do with slight valve damage. Then at some point down the road it drops a valve. It is worth checking before running it any more. These engines don't take kindly to out of time events. There are pictures of events like this on this site.
 

turbobrick240

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maine
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2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
Sounds like your hpfp got misaligned. Not a big deal like on the earlier diesels, but you should probably open it back up and check/realign the pump. Locking everything down.
 

pedroYUL

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Sep 8, 2011
Location
MI, USA
TDI
2004 wagon BEW; 2015 Passat CVCA; 2015 GSW CRUA
Update:
I scanned the car and found a P001600 code present.
After a bit of research, it looks like it may be timing after all. Possibly fuel pump out of time.
It is out of timing for sure. Same thing happened to me, just lock everything again, HPFP is allowed to move a little, then loosen the belt.

Use a wood clamp, one with soft plastic feet to just gently keep the belt by the crank, then work from the right keeping the belt tight all the way until you end with all the slack by the tensioner. Tension the belt and it should be 100% now.

Not sure if on all CR engines, but in these 2015 CVCA and CRUA, if valves and pistons meet, the rockers get obliterated and you will know for sure.
 

jetta 97

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Dallas (McKinney) ,TX ,USA
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Some do with slight valve damage. Then at some point down the road it drops a valve. It is worth checking before running it any more. These engines don't take kindly to out of time events. There are pictures of events like this on this site.
If he align Cam and Crank with tool he will be fine.
One Question comes in mine mind , did he replace Bolts at HPFP and other bolts what needs to be replaced with T/Belt job.
 

Lange17

Member
Joined
Jun 6, 2022
Location
North Carolina
TDI
2014 Passat SEL
Last update:
Thank you everyone for your help! This is a friendly and helpful forum, I will be sure to continue using.

I was able to get in and re-time everything. The hpfp was to blame I believe. About a tooth out from everything else. I have gotten pretty good at taking apart the front of the engine. I can get to the belt (including the motor mount) in about an hour now. Once I got everything timed correctly, it started without hesitation.

Like everyone and everything says. Take your time and use the proper equipment. You’ll only have to do it once.
 

DivineChaos

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Jul 27, 2019
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Minnesota
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mk6 jetta sportwagen tdi
Last update:
Thank you everyone for your help! This is a friendly and helpful forum, I will be sure to continue using.

I was able to get in and re-time everything. The hpfp was to blame I believe. About a tooth out from everything else. I have gotten pretty good at taking apart the front of the engine. I can get to the belt (including the motor mount) in about an hour now. Once I got everything timed correctly, it started without hesitation.

Like everyone and everything says. Take your time and use the proper equipment. You’ll only have to do it once.
yep i know that one. when my cp3 grenaded (pump wasnt put together properly and had a pebble in it) i had the pump out in about 2 hours. i was livid when it blew, stranding me 80 miles from home.
 

x1800MODMY360x

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Jun 27, 2021
Location
AZ, USA
TDI
2013 Passat TDI SEL
I'm dropping my engine/dsg to do the TB & DMF & exhaust all at the same time!

I got access to a car lift for a weekend.
 

Lange17

Member
Joined
Jun 6, 2022
Location
North Carolina
TDI
2014 Passat SEL
I'm dropping my engine/dsg to do the TB & DMF & exhaust all at the same time!

I got access to a car lift for a weekend.
I am still learning some lingo, DMF meaning dual mass flywheel? And TB being the throttle body?
Are they bad or upgrading?
Either way, good luck!
 

x1800MODMY360x

Veteran Member
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Jun 27, 2021
Location
AZ, USA
TDI
2013 Passat TDI SEL
I am still learning some lingo, DMF meaning dual mass flywheel? And TB being the throttle body?
Are they bad or upgrading?
Either way, good luck!
DMF = Dual Mass Flywheel, correct.
TB = Timing Belt.

Since i got to drop the DSG for the DMF, do the timing belt as well.
 
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