Im going to give this a go and replace my fifth injector as I reckon its leaking. Usual story with my IS220d. White smoke at warm up (lots of it). Usually on a hill near my house and when waiting at lights, just as the engine heats up - its like clockwork. Then its white smoke intermittently there afterwards, some days its bad other days not so bad. MPG low 20s on urban driving.
Here is what I have done.
1. EGR cleaned within an inch of its life
2. Inlet manifold off and cleaned - about a kg of black gunk came out. Long job took 2 days. Followed advice on this site - thanks Monocle!!! Drives way better now, still smokes
3. DPF off and professionally cleaned. Still smokes
4. MAF sensor changed. Still smoked. MAF values are high though and this is puzzling me. They are way out of spec at idle and hence why I changed the MAF. High at idle - 14 - 17 gm/s???
5. MAP sensor cleaned. Still smokes
6. EGR valve blanked off and mapped out. Mapper guy can reverse for me, I may do this yet.
7. DPF sensor disconnected and tested - still smokes Tried wiggle test with techstream connected up as per Smutts advice on this site - produces no results, suspect wiring is OK.
8. Dont think its HG, not losing coolant or gas.
Spoke to a few people, they think its a weeping 5th injector. Its an awkward spot, but I can see I can get at it if I remove a few bits and bobs. Ill do a write up on how I replaced it once I do, give me a couple of weeks. Covid lockdown has me wanting to get the bottom of this, and I now have the time.
My car is 2009 model BTW.
