The check engine light had come on my '09 XF Supercharged, couple of days ago. After that, i felt that the engine has not been responding to me while accelerating, even in dynamic mode. i took the car to the dealer and code showed up as P0128 and they replaced the thermostat and thermostat seal, along with with antifreeze. However after picking up the car and driving for 30 miles, that light came back on. Last night when i started the car after dinner, a thick cloud of white smoke came out and then it was fine. Same thing this morning. I am not sure if it is some sort of leak and the engine is burning more fuel??

Any experts could chime in, it would be of great help. I am taking it back to the dealer today...

 

There is a common problem with 2009 SC engines developing an air leak under the supercharger. They were all supposed to be fixed under warranty as this is an expensive repair of a simple failed part. Others with '09 SC cars should be able to post details.

 

When a have a CEL, you are supposed to be more considerate to the car. Beating on the car you will cause more damage.

Good luck and hopefully it's covered under warranty. Keep us posted!

 

@jagular Thanks for your insight. The reason I am not sure is because it did not spit out any code that indicated lean condition

@executive I did not beat up on the car. I usually drive with dynamic mode but i felt a lag in that mode too... will keep you guys posted

 

I am not sure the fault leads to a lean condition even though it involves an air leak. The leak may push measured and supercharged air out rather than drawing unmeasured air in. The former will cause the ECU to put excessive fuel in as it measures air taken in, calculates correct fuel amount but not all the air gets to the cylinders to be mixed with fuel, you then get excessive enrichment in the cylinders from correct fuel amounts. Boosted engines can produce odd results when air leaks out. Naturally aspirated engines always leak extra air in so produce lean effects.

BTW white smoke could be coolant burning. Isn't the SC intercooler water cooled?

 

Got the car back - it is fine now. The breather hose had loose connection and it was resecured. They also replaced the air filters due to airflow imbalance.

 

There you go, boosted air was being blown out, making the mixture too rich.

Not sure how the air filters would be involved. Mine has only one, does the SC have two?

 

Check engine light on a 2002 toyota highlander 4 cy?
I changed my air filter a few days ago. I noticed my check engine light come on today. Could i have done something wrong putting a new air filter in ? thanks

 

Air leaks downstream of the AMM will throw a CEL. Cheap code reader OBD II will get you the codes. That helps track down the issue.