2009 VW Transporter 1.9 TDI – Crank Sensor / No Start Issue

[bradley99]

Hi all,


I recently picked up a 2009 VW Transporter 1.9 TDI as a non-runner project, and I'm having trouble getting it to start. I was told it wasn’t starting when I bought it, so this wasn’t a surprise, but I’m hoping someone can help point me in the right direction.

Here's what’s happening:​

• The van will not start at all with the crankshaft position sensor plugged in – it just cranks over and does nothing.
• If I unplug the crankshaft position sensor, the van will eventually start (after a fair bit of cranking), but obviously doesn’t run perfectly without the sensor.
• A garage has already checked the timing, and they’ve confirmed it’s all correct.
• The crankshaft sensor has been replaced with a new one, but this brought me back to the original issue of it not starting at all (just cranking).
• I've noticed the engine oil is very thin, but I’m not sure if that’s connected or a separate issue.

My questions:​

• Has anyone had a similar issue where unplugging the crank sensor allowed the van to start?
• Could this be an issue with the ECU, wiring, cam sensor, or something else entirely?
• Would the thin oil possibly point to diesel dilution or something that could affect compression?

Any thoughts, tests I can run, or common faults on these 1.9 TDI engines that could help narrow this down would be greatly appreciated!


Thanks in advance!

 

[DXX]

If you provide a full diagnostics scan then I’m sure there will be some advice provided by the Forum.

Most importantly if you suspect the oil quality is sub-standard don’t run the engine before carrying out an oil / filter change. If you know the oil grade, oil mileage and consumption rate then I’d consider an oil analysis. If you don’t have that data then the value of the analysis is limited as ‘garbage in / garbage out’ results are just guesswork.

 

[bradley99]

If you provide a full diagnostics scan then I’m sure there will be some advice provided by the Forum.

Most importantly if you suspect the oil quality is sub-standard don’t run the engine before carrying out an oil / filter change. If you know the oil grade, oil mileage and consumption rate then I’d consider an oil analysis. If you don’t have that data then the value of the analysis is limited as ‘garbage in / garbage out’ results are just guesswork.

the problem is nothing is showing up on ther scanner if the crankshaft position sensor plugged in. erros come up when its unplugged but thats due to it being unplugged? but thats the only way to get it to start

 

[DXX]

If you provide a full scan posted on the Forum there maybe something found that the garage has missed.