Thanks Tom, here is my theory now we have eliminated the oil control ring for quite obvious reasons.

 

As the Mongrel did a track day at Castle Coombe after a remap, I would guess the combustion temperature has been very high and damaged the injector nozzles, white smoke is usually akin to cylinder temp being too low and not burning the fuel efficiently.

 

 Conclusion, check the injectors and replace if necessary, also have the map tweaked.

I believe he's already remove all four injectors and sent them off to be tested, all four have been given a fine bill of health and had new seals for refitting.

Camshaft, rockets and buckets etc have been checked when refitting the injectors.

Injectors have been tested. All Ok

Bad white smoke for a few seconds as cold and is a bit more reluctant to fire.

Smoke worse at lower revs than higher revs for some reason

Engine has always used a bit of oil but has been more dramatic up to combe, at combe and since combe.

Oil Temps at combe got to 130 degrees at combe, usually never got above 110. I am hoping hot oil is a clue. I don't know what can cause this.

I'm getting the car in a few hours, will report back. Something valve related is quite possible.

The other thing that has just sprung to mind, as the injectors have been in and out a few times, are you absolutely sure the injector lash clearance has been set correctly?

Not aware of what lash clearance even is, but they have always been refitted to factory spec.  Handy having the manuals in PDF.

Drove it today - about a mile....  Smoking the same, so left with my mate and he will drive it back to the garage for more tests Weds am.  He is thinking of doing some injector unplugging to rule them out entirely. but also he has said it could be a cracked head....  not like the car has had no abuse eh?  155,000 miles and been @ 220bhp since about 8,500 miles, and has only gone higher as mileage accrued.  Could be new head time.

Been on here five years and never seen a cracked head yet. At least not from antifreeze abuse!

To be honest. I have never seen these symptoms before at all - for anyone.

All my mate can say is something is letting fuel / oil in to the combustion chamber and once you have ruled out the injectors themselves, its likely to be the next line of track.

Nah, it's incomplete combustion, I've seen it recently with an engine that was down on compression on all cylinders.

Compression test has been done though.

Like i said, check the lash clearances on the injector rockers, they might be a little hit too tight.

Compression test has been done though.

 

Have you got the individual cylinder values to hand?

Have you got the individual cylinder values to hand?

 

I entrusted my mechanic to do it for me  I hope he knows what he is doing, haha!

 

I will need to look in to the lash clearances as never heard that term before.  What is it in laymans terms?

Its when you turn the cam till the rocker is at its lowest point, wind in the adjuster till the plunger bottoms out, then slacken it off, on oem injectors its 180 degrees slack off, but it might be different on aftermarket injectors. to do it properly you need a dti guage but it can be done by eye if you are hard core. There is a specific torque setting for the adjuster locking nut too buf i cant remember it off hand.

edit: make sure you purge the injector of fuel first, the slack ofv angle is 225 degrees on pd150 injectors i believe.

I entrusted my mechanic to do it for me  I hope he knows what he is doing, haha!

 

I will need to look in to the lash clearances as never heard that term before.  What is it in laymans terms?

 

Check with him that all four cylinders were >25 bar, it's an awful lot higher than your typical petrol turbo engine, it's nagging at me because you have three symptoms; mystery oil use, abnormal oil temperatures and incomplete combustion. I'm happy for you if I'm wrong, Ok?

cracked piston maybe I had that problem took the head off no4 was split right the way through only the sides were holding it together

Bite the bullet and whip the head off the thing.... Unless someone's got a fancy endoscope gadget you can compare cylinders through.

 

Discussion of cracked heads is interesting though. As I've head of heads (not TDI) cracking where the wall thickness was reduced.

 

If you're not losing oil or coolant though, it suggests something combustion related.

 

J.

Injector lash clearance settings http://www.audi-sport.net/xf/threads/how-to-guide-pd-tdi-injector-adjustment-clearance-lash.183040/

 

DB

Thanks. I was aware of the tdc tightening and slacking off routine.

lots of things can cause this:

• very common for PD heads to crack around the injector ports and then crack further up the stem and into the where the copper washer sits, causes pressurised fuel to leak into the cylinder on the down stroke and then blown out on the exhaust cycle (and as you are running around off boost and low rpm its shows up worse)
• bad timing or mapping can cause this (as Faboka pointed out it took us some time to get the DSSR in my polo to stop ploughing white smoke)
• cracking off the cylinder head around the valve seats to the injector ports

 

If i was me i'd load a stock pd130 map on the car and go for a drive (it will be fine with the DSSR injectors it just might smoke a lot of black just keep off the boost)

 

i'd be taping a fuel pressure gauge onto you tandem pump and monitoring the values while driving to make sure its not dropping pressure if it is then you could be looking at cracked fuel lines in the head

 

i would also drain the fuel off in your fuel filter and check its all clean and signs of black or discoloured diesels will point to contamination somewhere, culprit could be tandem pump or cracked cylinder head fuel lines

 

 

Just to add the cracked cylinder head in the injector port was what i feel was the cause of me killing my polo engine, fuel leaked into the bore and basically couldn't compress it and hay presto cracked piston

Its when you turn the cam till the rocker is at its lowest point, wind in the adjuster till the plunger bottoms out, then slacken it off, on oem injectors its 180 degrees slack off, but it might be different on aftermarket injectors. to do it properly you need a dti guage but it can be done by eye if you are hard core. There is a specific torque setting for the adjuster locking nut too buf i cant remember it off hand.

edit: make sure you purge the injector of fuel first, the slack ofv angle is 225 degrees on pd150 injectors i believe.

 

can be done by eye no need for a dial gauge and aftermarket injectors are dialed in to factory spec, so inlet lobe at its highest point per injector loosen lock nut wind down until resistance is felt then back off 180deg re-tighten lock nut

180° or 225° ?

People argue for both but I don't think it matters

202.5° it is.

A DTI gauge makes life easier for setting backlash but isn't essential due to the duration period on the lobe when it's fully open it makes it fairly easy to see.

I know this maybe a silly question but have you recently had an oil change carried out on the car? Could of maybe had too thin oil used.

Unsure regarding the PD engines but is there any other breathers on the engine other than the rocker cover one?

I had a blocked breather on a classic mini which cause positive crank pressure and resulted in blow by the rings resulting in oil usage.

Also on petrol engines, you could petrol wash the bores resulting in a reduced seal created by the piston rings, the compression results would be similar across them all but have an overall reduced reading that was was normal would be shown, but as I say unsure whether this would also apply to diesels.