Volkswagen TDI talk

[Rot Box]

Lets talk fuel delivery. The injector pump on a TDI like mine draws its own fuel from the tank which eliminates the need for a fuel 'lift' pump (kinda nice in some ways!). I've always had a steady stream of air bubbles in my clear supply hose that attaches to the injector pump. The car had an erratic-loping idle for a few seconds when stopping at a stop light or starting up after sitting. Not a huge deal as it still ran good but it was starting to get worse so I decided to find out what was going on.

I knew it was sucking in air from somewhere. I figured it was the fuel filter o-rings so I replaced them which didn't help. I started to look around for cracked lines and such. Then I stumbled upon this thread http://forums.tdiclub.com/showthread.php?t=68872 Turns out there is a troublesome check valve in the pickup tube that sits inside the tank. I believe there was enough restriction and the suction of the pump was great enough that it was pulling in air wherever it could--through an o-ring or something. I drilled out this check valve and woohoo no more air! I cannot for the life of me figure out why there's a check valve in the pickup tube but supposedly the replacement units don't have it.. Drilling it out was easy getting the spring out took a little time but not a big deal.

 

[Greg]

Nice! I had noticed those bubbles before, but they were pretty intermittent. Good find and fix!

How's the Jetta treating you otherwise?

 

[Rot Box]

How's the Jetta treating you otherwise?

I freaking love this car. Knowing what I know now I wish I would have bought one brand new in 00.

It's funny watching people run out of the gas station waving their arms at my wife 'miss---miss that's diesel you're using the wrong pump!!'

 

[Greg]

I freaking love this car. Knowing what I know now I wish I would have bought one brand new in 00.

It's funny watching people run out of the gas station waving their arms at my wife 'miss---miss that's diesel you're using the wrong pump!!'

Good to hear! It treated me well, very few issues after more than 100k miles! Sometimes I wish I would have kept it, my 2006 Jetta is nice but there are a few things that are a PITA about the car.

Funny about your wife! Neither I or my wife had that happen yet.

 

[Rot Box]

I cannot for the life of me figure out why there's a check valve in the pickup tube but supposedly the replacement units don't have it..

Now that I'm not half asleep I realize the check valve is there to keep the fuel primed. By removing it there is a chance of having fuel drain back to the tank if there's a leak upstream. I'm mostly worried about fuel filter changes..

After more reading it seems removing it is a common practice and it is also a point of blockage in very cold (like cache valley) winter weather. I'll keep everyone posted. Hopefully it works out.

 

[Unimog]

You will really notice the check valve missing if you run it out of fuel. Mine has bubbles, too, but I've never been too concerned about it.

 

[TRD270]

Well I just picked myself up another TDI Jetta, it's an 05 so it's a PD but after doing a lot of reading I'm not scared. Has a slush box behind it but after driving both I don't mind it. It's the newer triptonic slush box so maybe that helps.

 

[Greg]

Well I just picked myself up another TDI Jetta, it's an 05 so it's a PD but after doing a lot of reading I'm not scared. Has a slush box behind it but after driving both I don't mind it. It's the newer triptonic slush box so maybe that helps.

My PD has been fine so far, but they do seem to be more problematic than the older TDI's. Mine has the BRM engine, which is known for having camshaft wear issues... so I'll probably be replacing the cam before too long, out of preventative maintenance.

 

[TRD270]

From what I read it's hit or miss on the cam and only seems to be a real issue if your running the wrong oil

 

[Greg]

From what I read it's hit or miss on the cam and only seems to be a real issue if your running the wrong oil

I bought it used with 114k miles and unknown previous oil, I'll have to keep an eye on the cam.

 

[TRD270]

Mine has 143k but has carfax service maintenance at a dealerships damn near from new, one of the reasons I jumped on it

 

[Greg]

Mine has 143k but has carfax service maintenance at a dealerships damn near from new, one of the reasons I jumped on it

Nice! Always nice to buy a car that's been very well maintained.

 

[Rot Box]

My brother picked up a 03 Jetta TDI/5 speed last night. I'm super jealous because it's a wagon Sucky part is it died when he got it home and wouldn't restart... When I went over today to help investigate I noticed the supply side fuel lines were hooked up to the return side (T) of the fuel filter which explains the starving of fuel. It also might explain the need for a new injector pump (dealer installed injector pump only a few weeks old) as the fuel wasn't getting filtered. I'm really surprised it ran as long as it did I also wonder how long it's been that way. Anyway if it's anything like mine I'm sure he's going to love it.

 

[OCNORB]

Sweet. I wanted a wagon, but my love wanted a sedan...
Pretty strange that the dealer would get the lines swapped.

 

[TRD270]

My brother picked up a 03 Jetta TDI/5 speed last night. I'm super jealous because it's a wagon Sucky part is it died when he got it home and wouldn't restart... When I went over today to help investigate I noticed the supply side fuel lines were hooked up to the return side (T) of the fuel filter which explains the starving of fuel. It also might explain the need for a new injector pump (dealer installed injector pump only a few weeks old) as the fuel wasn't getting filtered. I'm really surprised it ran as long as it did I also wonder how long it's been that way. Anyway if it's anything like mine I'm sure he's going to love it.

Is it silver? Was it in Lehi? I think I test drove that one

 

[TRD270]

Just had a curiosity, wondering if one of you 5 speed guys can tell me what RPM your running at 70mph. With my slush box I'm sitting right around 2400. Also wondering what psi your running your tires. Factory recommends 33psi in the front 42 in the rear, but seemed bassackwards to me. Mine had 30psi all the way around, with the heavy motor sidewalls were bulging pretty bad, I bumped fronts to 40psi and rears to 35psi.

 

[Unimog]

My 02 5speed does 70 at 2400 also. I run my tires at about 36 front and 32 rear

 

[Spork]

I'm starting to wish my bug was another 4 inches up in the air...

 

[Greg]

I'm starting to wish my bug was another 4 inches up in the air...
View attachment 95126

Oh Noes!!! Always wondered how necessary those aftermarket skid plates were... now I know!

How'd it happen? Think there's internal damage, or just the oil pan?

 

[Spork]

Oh Noes!!! Always wondered how necessary those aftermarket skid plates were... now I know!

How'd it happen? Think there's internal damage, or just the oil pan?

My wife was driving and went to pass a semi and felt something hit underneath. I'm not sure what she hit, maybe a rock or Concrete piece. I think it's just the oil pan that's toast, she said it was still running fine when she shut it off and there was a puddle of oil when I towed her home so I'm hoping things are good.
This will be the second time I've replaced the oil pan, the first time I did it, I hit a softball sized rock and cracked the oil pan about a 1/4" hole that time. It's not too bad replacing the oil pan, nothing under it, just have to have a ball-end Allen wrench to get to all the bolts.