Leaking Injection Pump (2001 Jetta)

CrazySwede

New member
Joined
Nov 2, 2024
Location
Boise, ID
TDI
2001 Jetta TDI
First time poster so please bear with me...

I have a 2001 Jetta TDI (~250k mikes) and the injector pump has recently started leaking from a number different seals. Initially I thought it was just some bad seals , which is may very well be, so I bought the DieselGeek replacement kit with the intention of having a go at it. That said, the more I look into it, I suspect there might be something else going on. When I start the engine, diesel appears to be leaking out of nearly all the gaskets and there is a steady flow of diesel dripping off the bottom of the pump.

Other than the fuel leak, the engine seems to start and run fine. Additionally, I vacuum tested the pump per the DieselGeek video where they vacuum at the diesel return barb it it appears to hold a vacuum. (20 PSI). I am not sure if that implies anything about the seals.

All that said, the sudden onset and the extent of the leaks has me thinking that this may not be a simple seal issue. Perhaps the pressure is too high within the pump or some checkvalve might be stuck? (I was able to push air back up the return line through the filter (and pull fuel through it too) so I don't think the issue is with the return lines. An if I start the car with the return line removed (IP to filter), there is significant flow of fuel. (I am not sure if that is expected.)

Before I start replacing all the seals, does anyone have any thoughts if something else might be going on which I should look into?

Thanks!
 

The Cream Dolphin

Veteran Member
Joined
Feb 22, 2021
Location
Fernie, B.C. originally Dwight, ON
TDI
02 VW Golf TDI ALH 245k
If the seals are leaking, I would go ahead and replace them. There is a "pressure relief valve" that sometimes has its innards back out and it loses its function that you could also check on, I will find the how to. The return line is definitely normal to flow lots, it always sends more fuel than needed just to be sure it is never starved of fuel.
 

Prairieview

Veteran Member
Joined
Jul 9, 2017
Location
Too close to Sturgis 'ithole
TDI
Two 2000 Beetles, 2002 Jetta, 2002 gas avh Jetta, fleet of older 1.6 turbo and non's
Resealing is probably what you need. I never do it on the car. I perform a reseal on every car I acquire including the old 1.6 idi's and the alh's.

For over 25 years, I have run several ounces of hydraulic fluid per every 6 or so gallons (nothing scientific here....don't have Aspergers or something) of diesel fuel (a bit more when running some #1 in the winter). I believe that it helps to lubricate the pump and cushion the mechanical parts in pump and injectors. Hyd. fluid is also an effective detergent. I buy John Deere 303 compatible fluid in 5 gallon buckets and carry a non-leaking refuse oil bottle in the car or where I add fuel. I NEVER have any problems. Farm stores generally have the 5 gallon buckets on sale between Thanksgiving and New Years.

I have taken apart engines I have religiously run the fluid in and there is NO ash....just an extremely light gray that can be wiped off pistons and comb. chambers with a clean piece of cotton cloth. No, my engines don't smoke or stink. They just run and run. And, run hard.
 

CrazySwede

New member
Joined
Nov 2, 2024
Location
Boise, ID
TDI
2001 Jetta TDI
Quick update... I replaced all the seals and that did the trick. No more leaking. Thanks for the help on this!
 

Sting

Veteran Member
Joined
Jan 20, 2004
I did mine last year. My leaky one was the big round one in the head, but I did all four from the DieselGeek pack, since I was already in there and the car is 20 years old. Pretty straightforward job. You've taken your first step into a larger world. :D
 
Top