I've been reading on this forum and a couple of others for a day now trying to get the handle on what I am now experiencing. Decided on starting a new thread to lay out my issues and see if anyone can put it together for me in logical sequence of troubleshooting.

My 2008 LR3 HSE 4.4 V8 has 194,000 miles on it.
We bought it at 142,000 and have done maintenance as it comes up ourselves. Mostly oil changes, seals when leaking and air compressor system failures.( I have NOT done spark plugs)
I live in Mn where temps yesterday were -9 degrees F
On a 30 mile journey I noticed no issue until I left my first stop light and I left a haze of white smoke with a tinge of blue behind me. Thinking I may have an injector clogging I stepped on the accelerator to try and clear it. That mad the issue present again and the engine lose most all power. I could drive normal with a gentle pedal but could NOT get into it heavy at all or lose power. After each stop light I created that huge billow of smoke for my fellow drivers. I can smell a hint of oil in that smog left in the air.
I own the iLand diagnostic tool from Atlantic British and pulled codes on the side of the road. Threw random misfire code P0300 and also misfire on cylinders 2,4 and 6. I cleared codes and finished my few miles to destination to think this through. As it presented I figured I had head gasket issues but it was only blowing after idle....so I was not surprised to not have antifreeze in oil nor low antifreeze issues. That being the case I ended up driving the vehicle back home being cautious to keep rpm up at stop lights which helped the fog bank issue.

Reading these forums I started with replacing the PCV valve but that did not solve my issues. It is still pretty cold here today and my next planned move is to pull coils and plugs but I am writing this out while the vehicle warms up in a heated garage so I have the best chance at NOT breaking plastic lock tabs in removing things. My hope in writing this thread is that someone has dealt with this very issue and can help direct me to the issue so I don't just keep throwing money at this in new parts I may or may not need.

Another factor that I am unsure of is the possibility of bad fuel? My wife put 200 miles on the previous day with no issues and filled at a Sam's Club on the way home. Do my symptoms sound like a possible bad fuel situation? I had changed the oil a week before and my oil is now 1 quart low after a max of 400 miles.

After the PCV was replaced I still have issues with lack of power and smoking upon acceleration. Idling in the driveway seems just fine at various RPMs but under load this issue kicks in.

Any ideas for me???

Thank you in advance.

 

It sounds to me like you might want to do a compression test to rule out mechanical problems first.

 

I have my coils off and plugs out. I am getting all new this afternoon and that should tell me if I have bigger issues but I did find some fouled plugs. I think I am on the right track but will update this thread if it does or doesn’t solve the issue.

 

Could be the cold too. Extreme low incoming air temp plus potentially slushy gas (or higher water content from the temps) could've caused the computer to struggle to compensate.

That and rubber gaskets are vulnerable at those temperatures

 

Well I picked up the new coils and installed them along with the new plugs. I managed to break my PCV to manifold tube when I tried to get it out of my way. That baby is brittle! So....I did a temp fix for that so it would allow me to test the vehicle and with the exception of installing my new PCV/manifold tube on Monday I think this issue has been resolved. I still plan on running the fuel down a bit and filling with higher octane fuel. The LR3 is running great now and after a few miles quit blowing white smoke on acceleration.

I'll bounce back in here and update if something else develops with this but it seems to be just fine now and has not thrown any codes in 15 miles of test driving. Man.....I was about to go Toyota shopping! LOL

 

My first thought is running a compression test as well. It sounds like you are burning oil, and perhaps the oil getting into the combustion chamber is fouling your spark plugs, causing
the misfire. Replacing the plugs might fix the misfire in the short term, but they will foul again over time, then the misfire will return. Definitely keep a close eye on your oil level.

Give the PCV a good check again, not just the valve but also the hose and connections to manifold. A clog anywhere in there will cause oil burning.

 

I'm going through the exact same issue, I had no choice but to put 87 oct walmart gas in it one time on the way home from Moab, it seemed to run fine but then that first cloud of smoke was horrendous, I did PCV, no better, full tank of 93 seemed better but reoccurred, I got a flashing check engine light yesterday, I have all the P0300 codes for cylinders 2,4,6 and 8, anyway thanks so much for posting this helps a lot, I'll be getting coils I suppose, I was about to park it and shop for toyotas myself,

 

though mine seems to happen on left turns with a rattle from the engine somewhere and then plumes of whitish smoke

 

My issue that I had originally posted this thread for has not come back in many hundred of miles of driving now so I think I have that issue sorted!

Next is getting my suspension dialed in again and the air system working as intended once again! I don’t want to switch to coil suspension as I enjoy my Landy as built(when it works as built)!