I have a 2004 (54) T5, which I bought recently with a damaged engine.

The van was a non runner when I bought it, and some of you may remember me asking about scored cylinders etc...

Well basically, the van went off to a company in Essex to have a rebuild. they ended up replacing the bottom end and renewing camshaft bearings puls a few other bits...

Now the problem is, the van will not start. It has been rebuilt properly, and will run if fuel is induced into it, but cannot start or run on its own.

The guys at the garage are at a loss, as they are engineers rather than electronics specialists; and have had the van VAG COM'ed (or checked by a bosch engineer apparently)

The faults being read are something along the lines of "camshaft sensor error" but the timing cannot be wrong otherwise the van wouldn't run with fuel induced, would it?

They seem to think the ECU is at fault, and are due to send it off for a diagnostic check from a tuning specialist soon.

Can anyone here (read anyone who has read this far!) suggest what the problem might be?

Alternatively, does anyone know of a reasonably priced (but good) ECU specialist in the Lakeside area that might be able to have a look at it for me?

I'm beginning to wish I'd never bought it...

If you're getting a camshaft position sensor fault then that would explain why it doesn't start.

Agreed - camshaft position sensors are only a few quid and if it's sending bad signals, the car won't start. Had it on a previous car

Chris

We had a bloke in the shop with a similar problem on his Mk1 Octy Diesel, would only run with the help of easy start. Turns out following an injection pump rebuild it had been timed up 180 degrees out :eek:. Might be worth getting the timing double checked.

Gray

Could give AMD a shout, very near Lakeside.

Contact AmD Technik

We had a bloke in the shop with a similar problem on his Mk1 Octy Diesel, would only run with the help of easy start. Turns out following an injection pump rebuild it had been timed up 180 degrees out :eek:. Might be worth getting the timing double checked.

Gray

That's easy to do so get that checked.

That's easy to do so get that checked.

Could it run on easy start with the timing 180 degrees out? :eek:

It's scary how little I know about diesels...

I'll suggest both the timing issue and the camshaft sensor, and report back.

Thanks for the suggestions so far...

Hang about.

Diesels are started by glow-plugs, which are always on during start-up and then switched-off when the engine is running. Being always on means that ignition timing of the type used in petrol fuelled vehicles is unnecessary. During normal running, the momentum of the pistons in high compression diesels is sufficient to ignite the cetane based fuel without the introduction of an external electrically generated spark.

So saying that the timing is out is not relevant to diesels unless your're referring to the relative position of the rotating mechanical bits i.e. camshaft and crankshaft. In those circumstances, wrong timing means that moving parts collide in the cylinders. If its an interference design engine, where the valves and pistons take turns occupying the same space in the cylinders then off-timing must means a mechanical collision of parts ?

So if the diesel engine won't start and is showing a "timing error", then, I would suggest that the ECU is doing its job by preventing an expensive mechanical collision of parts. Somebody's rebuilt the engine incorrectly.

Presumably the engine will not turn over at all ?

Nick

Edited 24 October, 200916 yr by Clunkclick

Presumably the engine will not turn over at all ?

Nick

Hi Nick,

the engine will run fine if fuel is induced (they apparently use a light ether based fuel to test if starting is problematic); but the engine will not fuel itself.

Because of this they are saying that the timing must be correct otherwise the engine wouldn't run with induced fuel.

I don't understand enough about diesels to comment on this fact, but Gray (above) suggested that a customer of theirs had a similar problem with an Octy diesel that was 180degrees out on the timing.

I don't know if they have replaced the camshaft sensor (he said when tested by the Bosch diagnostics guy that "Camshaft error" was coming up sometimes)

I'm really at a loss here (and tbh the engine rebuilders seem to be too) and can't afford to chuck much more money at this van - I also really can't afford to be without it for much longer!!

Any suggestions (sensible ones) on what to try next would be great...

As an aside, would it be worth whipping the ECU out and sending it off to someone (like Shark90?) to be checked, or are there other things I should get them to look at first?

John:(

It definitely could run with the timing set incorrectly, I've seen it before. A good way to check it would be to log the injected quanitites with VCDS when it's running. Going back to the camshaft position sensor, if the ECU can't properly determine the timing, it won't fire. I'd still be looking at the sensor or the timing really.

I very much doubt it's the ECU itself.

If the timing is out the injector timing is out = wont run. If the cam sensor is goosed it wont run as the ECU cannot get timing for the injectors.

If the timing is out the injector timing is out = wont run. If the cam sensor is goosed it wont run as the ECU cannot get timing for the injectors.

its a commonrail diesel - doesn't that mean the injectors are pulsed individually from the ECU rather than from a mechanical pump?

Suggested the timing mistake to the garage and they agreed it was a possibility; although they said with fuel being induced it runs very smoothly, whereas if there was a timing issue (180degrees out) they would have expected it to run quite rough.

They also said they are holding off on the cam position sensor as it is £120 for a new one, whereas having the ECU checked is about £70.

If that turns out to be fine, then they have said they may well whip the engine out again and reverse the timing. (The problem is, they didn't strip the engine down, a VW garage did that before I bought it, so no one knows if the engine was turned at all with the head off...)

I wouldn't expect a camshaft sensor to cost that much!

its a commonrail diesel - doesn't that mean the injectors are pulsed individually from the ECU rather than from a mechanical pump?

Suggested the timing mistake to the garage and they agreed it was a possibility; although they said with fuel being induced it runs very smoothly, whereas if there was a timing issue (180degrees out) they would have expected it to run quite rough.

They also said they are holding off on the cam position sensor as it is £120 for a new one, whereas having the ECU checked is about £70.

If that turns out to be fine, then they have said they may well whip the engine out again and reverse the timing. (The problem is, they didn't strip the engine down, a VW garage did that before I bought it, so no one knows if the engine was turned at all with the head off...)

Mate it's a PD diesel like the 1.9 and the 2.0.

If the timing is out then the ECU will try it's damnest to make the engine run smoothly, which is why I suggested checking the injected quanitities per cylinder in the measuring blocks, but you need it to be running for that.

And it shouldn't matter whether the engine's been turned or not, if they timed it up properly using pins and markings then it should be fine. It really sounds to me like they might have timed it incorrectly if that comment came from them..

WikiP says that 2003- 09 T5 has a TDI Engine

Volkswagen Transporter (T5) - Wikipedia, the free encyclopedia

And another wiki page says that only the larger TDI engines and the 2.0L fitted to the Tiguan are common rail

Common rail - Wikipedia, the free encyclopedia

So the engine in question is most probably based on PD technology

Unit Injector - Wikipedia, the free encyclopedia - see VW technical PDF at reference 5, which confirms that the 1.9 TDI is a hybrid - no fuel distributor but common rail instead with mechanically actuated injection and an electrically controlled, via the J248 unit, fuel supply to each injector.

The manual says that there are two timing reference points on the cam shaft (presumably 180 degrees apart), so that only 2 cylinders need to cycle before the EMU electronics are synchronised.

Bet the issue's electrical because of huge number of sensor inputs to the J248 unit, including sensors on the clutch and brake pedal - see P. 39

Have you checked the glow-plug operation which is needed for starting when air temp goes below 9C ?

As the previous poster said if mechanical timing was out running would be roughhhhhhh or mechnically crunchy ! But if somethings inhibiting the electrical signals to the solenoids then they may not be releasing any fuel to the injectors or doing so at the wrong time and you would have difficulty starting but once running there would be sufficient unburnt fuel lingering in the system to keep it running. Exhaust would be a bit dirty.

Nick

Edited 25 October, 200916 yr by Clunkclick

Nick, I'm really sorry mate, but I didn't understand your last post.

Mine is the 2.5L 5 cylinder 130bhp engine (or thereabouts) - I did hear one of the many garages that phoned me touting for business mentioning mine being a PD engine, but he called it a "pumper diesel" (said with a broad and totally untrustworthy brummie accent) so I really don't know.

The garage are sending the ECU off to be checked on Monday, so I guess I'll have more info early next week.

Be interesting to see who's right (I hope it's the timing that's out, because then I won't have to fork out loads more money for a new ecu...)

Edited 30 October, 200916 yr by jonnycatbiscuit

"Pumper diesel"

Pumpe Düse I think he meant. Which means "Unit Injector".

I still reckon it's the timing from what you've posted above.

Looking at the VW technical training doc in my last post it looks like all the TDI engines irrespective of size are common rail, i.e. there is in effect a high-pressure fuel reservoir which connects to all the injectors, so the Wiki comment about a distinction is not correct.

The diagrams in the technical doc seem to indicate that the timing of the injection of fuel is controlled by a mechanically actuated piston inside each injector and that this is driven by the inlet camshaft . Further, it appears that this is independent of the exhaust side -presume that your engine is DOHC ? So you could have the situiation where the inlet camshaft is out-of-position but not causing any mechanical collisions in the cylinder.

Also, it appears that the fuel inlet solenoids attached to each injector and which permit fuel to be admitted to the injector act simply to isolate the injector from the common rail high-pressure reservoir at the moment of injection i.e. the power to the solenoid goes off and the spring in the solenoid closes the inlet to the injector - thus preventing a surge of fuel entering the cylinder as would occur if the both the injector nozzle and access to the common rail were simultaneosly open.

So I think there's a possibility of two kinds of "Timing" error relating to the injection of fuel:-

1). The inlet camshaft is out of position causing the injector orifice to open at an inappropriate position in relation to the piston. If all else was well this could cause merely rough running - this could be reasonably likely given your rebuild.

2)The solenoids are not working or synchronising with the inlet camshaft. This could be caused by a fault in the solenoid, a faulty J248 unit, faulty wiring and connections or a faulty hall effect sensor for the Camshaft position.

Of course, you could find that both these faults are occuring together.

I think engines from 2009 onwards dispense with mechanical actuation of the injector and reliy on a purely electrical means to open and close the injector orifice (Piezo - electric), so error two, if it occurs, becomes an electrical issue.

Incidentally, you refer to scoring of the cylinders being the reason for the re-build, do you know what caused that ?

The literature indicates that modern diesels seem to be very sensitive to fuel constituents.

Nick

being a 5 pot it's doesn't matter if the crank has been turned or not, you dont have 2 cylinders rising and falling together, so when piston 1 is at the top that is TDC. if the timing were out i would say that it wouldn't run at all.

just looked it up and it appears the 2.5 is a unit injector engine (PD) which is new to me, i didn't even know they made a 5 cyl PD

as a matter of interest was the van a runner before the engine blew up?? i suppose they have checked the most basic of things like the fuel pump relay and fuse? iirc you can do a test on vag-com to check the fuel pump relay.. it might sound daft but if the thing runs on easy-start then clearly it is not a mechanical fault and it is a fuel supply problem..

if my memory serves me right from fiddling with my old polo, on the pd engines you do not need the camshaft sensor plugged in for the engine to run, it should be able to run solely off the crank sensor and vice versa, but obviously it will show an error/check light

If you disconnect the camshaft sensor it will run on the 4pots, but as above it shows an engine check light and might not be so smooth.

Hi Nick,

can you come and fix it for me please?

Thanks

John

Having just spoken to my helpful engineer/boss-man chap at the garage; they have informed me that the camshaft has been taken out and turned 180 degrees, and after that the engine would not run at all (I forgot to ask if not having the ecu would make a difference here); so they are convinced the timing was spot on when the engine was re assembled.

So at the moment it is all pointing towards an electrical problem and quite possibly the ecu.

I know some of you think this is unlikely; but having spoken also to a friend who works for JCB and is quite clever when it comes to diesel engines; he informed me that one of their work vans (a VW Crafter) engines went into meltdown after the ecu failed and caused an overfuelling issue.

I'm hoping for a report on what actually caused the breakdown in the first place; when I get it I'll summarise it on here in case it suggests another course of action to one of you guys. Until then, any further suggestions are more than welcome!

Im siding with Shark here and not Nick..

Nick's pointing you in the direction of a Dual Over-head cam common rail which it definitely isn't!

The 2.5PD are an 8v, single cam head,with seperate lobes for the unit injectors.. The injectors are fed by a lower pressure pump and then the unit injectors use the lobe to pump its conents up to pressure, the ecu then decides when to inject during this "pumped up" period with a solenoid.

Kev

The 2.5PD are an 8v, single cam head,with seperate lobes for the unit injectors.. The injectors are fed by a lower pressure pump and then the unit injectors use the lobe to pump its conents up to pressure, the ecu then decides when to inject during this "pumped up" period with a solenoid.

Kev

i'm sure you mean 10 valve

This is what the block looked like when I got it...

...if that helps anyone...