Hi all. I'm new here. I'm fairly clueless when it comes to the inner workings of my vehicle, or any vehicle for that matter. Been pulling what's left of my hair out after the last 18 months of troubles with my bus.

2006 T5 VW Caravelle 2.5tdi 128kw (auto)
Milage ± 200 000kms

Problem started some time ago with leaking oil, losing water, and white smoke. Diagnoses was a cracked block and gasket replacement etc. Block was repaired.

Work done over the last few months:

Head was skimmed and a pressure test was done

New valves and stem seals done

New pistons, rings, and bearings done

New glow plugs

New top gasket and water pump

Compression test done (status: good)

• Turbo is still good

PROBLEM: The van still smokes excessively. Edit for clarity: Thick 'clean' clouds of white smoke. Mechanic says there's no particular smell to the smoke, and the smoke seems to disappear at a higher speeds around 100km/h but as soon as the van idles at a standstill the smoke is back.

It's been to numerous people for a diagnosis and nothing. Any ideas on what the underlying issue might be?

Colour of new smoke?

Mileage on turbo, original?

Is it smoking thick clouds or a light puff?

Black smoke on a TDI is fuel.

So either a boost leak, or injector issue

Thanks Callum, it's 'clean' thick white smoke

Turbo was replaced around 100 000 kms

Callum229 wrote: ↑Thu May 06, 2021 9:26 am Colour of new smoke?

Mileage on turbo, original?

Is it smoking thick clouds or a light puff?

White smoke is unburned fuel or coolant. I am sure coolant level hasn't dropped.

Could be a stuck injector (dangerous as could hydrolock). Or timing is off and unburnt fuel is leaking out when exhaust valve is opened(it should run poorly though).

If your exhaust still smokes after you switch off, it could be serious as that means fuel is burning on the hot exhaust.

take off glow plugs and check which cylinder is wet and get your injectors tested before serious damage occurs.

Really appreciate this feedback! I'll relay to the mechanic accordingly.

Oh also could be EGR cooler leaking coolant and water in diesel. But thick white smoke will make the van run very poorly especially if water is in the diesel.

Where are you based? If in Gauteng, @panic-mechanic could assist...

Have the same issue , turns out its a cracked sleeve and I'm burning coolant. Hardly uses coolant though... Half litre a week at most.How was the block repaired?

RobRSA wrote: ↑Wed May 05, 2021 11:55 pm Problem started some time ago with leaking oil, losing water, and white smoke. Diagnoses was a cracked block and gasket replacement etc. Block was repaired.

I missed this, what was done to the block? If these 2.5 TDi' are like the ones in the Touareg, the cylinder walls are plasma coated and cannot be redone, which limits options when needing to do repairs.

Neuk wrote: ↑Fri May 07, 2021 12:28 pm

RobRSA wrote: ↑Wed May 05, 2021 11:55 pm Problem started some time ago with leaking oil, losing water, and white smoke. Diagnoses was a cracked block and gasket replacement etc. Block was repaired.

I missed this, what was done to the block? If these 2.5 TDi' are like the ones in the Touareg, the cylinder walls are plasma coated and cannot be redone, which limits options when needing to do repairs.

Engine are basically the same between Transporter and Touareg. They are just mounted longitudinal in Touareg and transverse in the Kombis.