Other XC90 Problem: Excessive smoke (inconsistently)

[NMB]

Originally Posted by dingov70

NMB I would not use seafoam directly in cylinders , if the rings had stuck you would struggle to start the engine & the blowby would be very obvious . DPF & CAT's are prone to "damage " when unsuitable products are burnt in the engine . The two biggest killers of turbo's are lack of oil changes & switching off after a highspeed run with no time for turbo to slow & cool down . Your description of the smoke after a run & idleing would still make me suspect / inspect the turbo , everything hot , tolerances wider , oil thinner & leaking into hot downstream side of turbo , it's the same as getting a frying pan way too hot & the oil smokes

I’m not worried about the main rings being stuck – I’m just aware of the oil controlling is not scraping the cylinder bores which could cause the excessive smoke. I thought using the seafoam would help clean these out potentially?

[dingov70]

Very unlikely rings are stuck , leaking turbo , blocked crankcase vent system , excessive oil level are more likely causes . Start simple & delve deeper as required . With modern oils you are only likely to suffer stuck rings if the top of the engine is filled with thick & I mean thick black gunge .

But by that point you would hear a lot of mechanical noise from the top of the engine . The only real way to deal with stuck rings is to strip the engine , scrape the ring grooves clean & rebuild , anything else is a temporary ( very temporary ) solution .

Look up the end of your exhaust pipe , does it look wet / shiny ? , that would be oil burning / leaking into the exhaust . From the symptoms given I would take a long look into the exhaust side of the turbo as I feel that may well provide your answers

[dambat]

On some engines (prius is a good example, where regen braking replaces engine braking), never using engine braking lets the rings relax, and leads to steady loss of oil. Going back to engine braking expands the rings and greatly helps with oil loss problems.

Oil loss through rings is fairly steady, and maximised during engine braking, so unlikely to be your problem.

[NMB]

1) I have performed a DPF regen with VIDA and it was successful after 34 minutes - the Soot filter has cleared fro the moment and the car drives normally - DONE.
2) I have replaced the oil and filter with 0 / 40 fully synthetic oil - DONE.
3) I will be replacing the PCV and checking the breather system for any blockages - part ordered and awaiting delivery. - Done - System is fine and PVC membrane is in good condition and working - All pipes clear.
4) I will be taking apart and be cleaning the ERG/intake assembly - awaiting carb cleaner - DONE - the pipes were an absolute mess and i'd guess that the carbon buildup reduced the diameter of the piping by 30% in places. All now clean.
5) I was concerned with too much fuel in the cylinders due to faulty injectors but my VIDA reports all injectors consistent with readings of 0.3 through to -.39 - this appears to be very good and normal. DONE
6) I may consider a compression test but as the engine runs nicely and the injectors are reporting constant numbers I don't see the benefit of this immediately - Will do if I'm flummoxed. DONE - via VIDA and all compression tests are constant with no cylinder obviously low.
7) I have performed an oil engine flush with Moly Slip Engine Flush - I ran the engine for 12 minutes with the flush adative added to the oil and before i start the car with the replacement turbo i'll replace the oil. I intend to then run the car up-to temprature and perform another engine oil change with filter this time to ensure that the system has been cleaned as much as possible - In progress
8) I have started to remove the turbo - what a job! It's really nearly ready to take out but I can feel some movent in the turbine so I have reasonable hopes that this is the item at fault. I haven't yet got the induction side off but the exhaust side is not contaminated with oil. As I have been unable to find a video of the removal of the turbo I have been taking photos and will try to stitch together a short video on how to remove.

I have to say that as a home DIY mechanic the difficulty factor of turbo removal (based on my skill level) is probably an 8 or 9 out of 10. Oddly its not a complicated job but just very difficult to access as 90% is over the engine with a couple of bolts accessed from underneath.

Once I have installed the replacement turbo I'll let you know...

1) if the car starts and drives again!!!
2) if the smoke issue has been resolved.

Hope for dry weather so I can finish the turbo today.

[SwissXC90]

I've heard the turbo replacement is a pig of a job

I'm guessing with clean EGR and inlet manifold (as much as possible) and a new turbo, you will notice a huge difference.

[NMB]

Originally Posted by SwissXC90

I've heard the turbo replacement is a pig of a job

I'm guessing with clean EGR and inlet manifold (as much as possible) and a new turbo, you will notice a huge difference.

I bloody hope so!

[NMB]

So yes the turbo replacement is a pig of a job but it’s disconnected and ready to be removed.

I however need help on how to get it out as there’s not enough space. I’m considering disconnecting the prop shaft to allow the engine to tilt as there’s not enough movement with the engine mounts loose end – any suggestions?

[gmonag]

I did warn you. You have to remove the bevel gearbox.

[NMB]

Originally Posted by gmonag

I did warn you. You have to remove the bevel gearbox.

And you get it out the bottom or the top?

[gmonag]

Out of the bottom