2.5 TDI Transporter BPC 2009 info thread

[Greg Roles]

Jesus H Christ I'm a loser. Spent the weekend trying to prime the fuel rail and injectors, diesel all over me, the car, and half the suburb. No start. A spray of "Start Ya Bastard" with the glowplug unplugged, and she gives a rev. Been pondering this half of today, spent hours re-reading forums, watching YouTube, then finally re-read both the manuals and guess what, the penny dropped, I skipped a step in the timing process in this weekends last cam install check. The small round crank turning tool does indeed have a TDC mark, but as the crank spins TWICE as fast as the cam, you have to THEN check that TDC with the big crank and pin into head tool, if the pin does not fit in the engine mount bolt hole, you have to turn the crank another revolution!!!! I've not thought that through, been skipping the second big tool and pin check, and I bet my left testicle I have the engine to cam exactly 180 degrees out. It's not hitting valves as I'm indeed using TDC on the crank turning tool, but the injectors will probably be firing at bottom of the stroke! Don't skip steps people, nor think you are smarter than the laborious timing process and tools.

To be fair there's quite a debate up on the UK T4 forums about this, and two guys who obviously know the engine well go back and forth as to if you can indeed get the cam 180 out, and I can see both sides to that argument, plus this whole post is just my conclusion why it won't start, could be wrong....but need to recheck the timing!

SO, more late nights pulling it apart yet again because I'm dumb, and thought I was smart.....wish me luck.

[Greg Roles]

Ok got it half done yesterday, damn work always gets in the way of things!

I pulled my fuel rail pressure relief valve while in there, and it is hard to blow through, so need to investigate that. The videos from PT Precision I posted earlier go into this, but I can't work out the answer, so have asked Phil for help there. Anyone down his way with a 2.5, well he'd be the guy to use as a service centre, IF he's prepared to touch a 5 cylinder ever again!

So far my timing seems spot on, but need to turn it over 4 cycles and keep checking, happening around work today.....I'll run a lap of the industrial complex naked if she up and runs just because I timed it wrong.....stay tuned.

[Greg Roles]

OK I'm back into it this arvo, and have found the problem with the cheaper Ebay timing tools. Here is a pic of the two tools in question, simpler to show them than to talk codes, which are shown in the timing diagram above. I'm calling them the silver crank tool, and the black pin into head tool. You remove one bolt from the side engine mount, the black arm and pin goes into this, again, as shown in the diagram above.




The crank spins twice as fast as the cam, so you effectively have two crank TDC for every full cam turn. You are supposed to use the silver tool to locate TDC on the crank, then check you have the "correct" TDC with the black arm tool and pin. EDIT: This is keyed but very very shallow pins make it easy to get wrong. If you look at the below pic of the backside, you will see the pins have different distances to the centre. The black arm tool will only bolt in with the much smaller recessed bolt when you have it correct. This tool gives you the compression stroke TDC. How this can be different to any other cylinder 1 TDC is beyond me, but I'm taking the designers word for it. Plenty of threads online where people are confused what "cylinder 1 " actually is, but it is as you would expect, the furthest cylinder from the gearbox, so right over the drivers side on our RHD cars. Front cylinder on the Toureg R5.



I did read on a UK thread about the "cheaper" tools fitting "both ways" but this was in reference to the upper, cam location tool T10193. EDIT: It sure can. What this means is the genuine, Snap off tool is a tight fit, and only lets you put the cam in the correct orientation. The China tool I have is loose enough that you can get it wrong, and I can't help but think this has been my problem in getting her to fire. Here is a great YouTube video on the differences, in German, but easy to follow. I'm hunting for a genuine tool that's not going to cost me $700......



Given the China tool seems quite loose, and short from the measurements in the video above, I looked at mine, and you can see it's rounded off on the lower edges of the keys, shows it allows the cam to be a bit out, even when locked. I've been watching my Torsion values on VCDS ( the relation of cam to crank ) and it's not gone over 3-ish on cranking, but apparently at some magic number beyond 3 it simply won't start ( so I have read ). It certainly doesn't have to be zero, but lower seems better, be that positive or negative. Seems as the timing gear bushes wear, this throws the relationship out and the torsion value grows. The bit I cut out of my cam tool is to clear the much prouder small welsh plug in the AMC head, and I can't get it loose, it's hella tight.



So for anyone pondering tool purchases, it might be smarter to hire a decent set, I know there are options to hire some of the expensive tool sets at some of the tool shops, so that might be a smarter option, but I then found a Russian video where ol' mate does this, so I might even try that too! Yep piece of steel holding it dead level, his car starts right up when he gets it back together.....

[Greg Roles]

EDIT: I've edited these posts as I have spent a fortnight going around in circles, and it does seem to be down to cam timing and the issues I have with the China cam locking tool as outlined above.

You most certainly can get the cam 180 degrees out, and as a last resort I simply flipped the cam 180, and also flipped the cam gear to suit the injector lobes. There are 7 notches cut out in the cam gear front plate, these trigger the cam sensor to inject and the correct orientation of the gear is with these lining up with the injector lobes on the cam. Obviously two notches won't align with anything, no doubt these are keys for the ECU to know the cam orientation or something. Anyway if you have the cam to cam gear out of correct orientation these notches don't line up at all. Just something to keep in mind.

Also for reference the "other" cam tool in the timing kit is used on the V10 5.0 TDI, in the right hand side head, with the "normal" T5 transporter tool used in the left hand head. It's useless on the 2.5. V10 pics below:

[Greg Roles]

With regard fuel priming it seems the transfer "lifter" pump out of the fuel tank should run about 7psi, but the built in filter can get clogged over time and the flow can be down, was one of the problems Phil had from the PT precision videos mentioned earlier, correct pressure but poor flow. The tandem pump then raises it up for the injector rail, and the rail relief valve holds it at 1 bar or about 14psi according to the Erwin VW engine overview. So it makes me wonder how a transfer pump that only manages 7psi can prime a dry head and rail designed to hold 14psi through that valve, will crack it today and see if any bubbles etc comes out......just a FYI. I read endless threads of people spending ages trying to get an engine going again after pulling injectors and introducing air to PD fuel systems. So glad the Yeti is common rail, so much easier when it's all external. Just imagine having to prime a V10 Toureg!!

That pressure relief valve seems impossible to buy too, so glad mine seems to be hard to blow through and thus seems OK. If there is no restriction in this valve, it's had it and you are going to have to get a whole rail from a wrecker.

[Greg Roles]

Lifter pump out of the tank isn't registering any pressure, and has a flow, but very, very poor one. I also note the clip on connectors on top of the fuel filter are leaking a bit, so that will both drop some pressure and possibly add air to the lines. The VF line from the fuel tank is a 6.3 connector, and the VM out to the tandem pump is a 7.89 sized connector, all available cheaply off eBay under "fuel line quick connect", took me a while to work out what to call them. My BPC only has the two connections unlike earlier ones with 4.

Some start ya bastard fluid gave her a rev, so it's down to fuel and has to be cam timing as I've primed the be-Jesus out of it in both cam orientations with no fire.

[gregned]

Thanks for the update Greg
Really appreciate you taking the time to write up your progress, findings and offer helpful tips along the way

[Greg Roles]

Welcome. If I could have found a comprehensive set of answers on the 2.5 engine 4 months ago, I'd have saved a ton of time and money, and be driving the van by now instead of still butting heads with it. I hope it saves someone else.

[Syncrotek]

Hi Greg,
When the tank is down is a good time to add a fuel line to the pump for an auxiliary heater, either coolant or parking, for you or the next owner. I have done that job, its fairly easy.
One other thing - did you notice if the glow plugs are ceramic or metal type ?
All the best.

[Greg Roles]

Good idea, easy enough to do, but not a lot of call for heaters here in QLD. Air conditioner more like it!!

I took out metallic and put back in metallic. Ceramic sounds too breakable!