2015 Passat 2.0 Tdi CRL Chuffing and ticking noise

[Jon44w]

Any help offered thanks in advance.....

I have a 2015 2.0 Tdi Passat with a CRL Engine. The car has done 115,000 miles and had the belt done at 110,000 miles.

Recently the car has developed a chuffing noise on idle and a ticking noise when revved.

VCDS shows injector 3 reading around 1.2 when started from cold. (All other injectors good) but if i take it for a small drive (during which the injectors all read good) then the bad reading switches to injector 1 which goes to 1.26, inj 2 is -0.7, inj 3 is 0.51 and inj 4 is -1.07

When injector 1 is bad the chuffing noise at idle disappears but the ticking still stays when revved.

A compression test shows

cylinder 1 - 320
cylinder 2 - 160
cylinder 3 - 360
cylinder 4 - 350

The owner is complaining that the car is using 1 litre of oil every 2 weeks but theres no leaks or smoke from the exhaust. The car drives fine with no loss of power. Any suggestions or ideas would be much appreciated thanks.

[Crasher]

Do you known if injector 2 has been replaced? The bolt MUST NOT be reused but people do and this causes leaks or even the injector pair to blow out. If it isn't a compression leak past the injector, your customer has a serious bill looming.

[Jon44w]

Thanks crasher. It doesn’t look like any injectors have been replaced. I fear bad news too but the noise sounds similar to how the old pd engines camshafts lobes used to wear. The chuffing is back through the inlet manifold. I forgot to say when you take the oil filter cap off there’s a little bit of blow back there too. No engine faults logged.

[Crasher]

Those have roller cams and I haven't had any fail, that low compression is concerning.

[Jon44w]

Second hand engine is on the way with a lot less miles. I think it’s the best option with the low compression. Interestingly there are a lot of these selling and a big demand which isn’t good.

[Crasher]

I have given up on used engines, boxes and electronics, the grief they have caused me over the years is depressing.