2012 TL has engine idle problem. When the a/c comes on the idle drops and has that feeling of almost die ing. I have 50,000 mile and think it needs throttle body cleaned. Does anyone have the service manual section for this? I know I need to buy one, was waiting and hoping they would come down in price.
Thanks

 

A service manual is available to download free since ArtUnique posted a link on this forum some time ago, but not sure if it covers your year. Many items are common across all years though. Search and you shall find. I'm not sure if or how idle speed is adjustable since it's all computerized and you have drive by wire accelerator pedal, no mechanical connection. The car is supposed to figure it out automatically. If you changed the battery it takes a few cycles for it to relearn where the idle should be.

 

It's not only the TB that needs cleaning but also the EGR bypass under the intake manifold cover, on the right side. It's a metal tube bolted inside the manifold.

Carb cleaner and a toothbrush will do it. Not good to directly spray anything in the throttle body while the engine is running. Despite what they say that sprays are catalytic safe, any misfire can ignite fuel thrown on the cat and collapse it under extreme heat. Best thing to do is remove the intake manifold and clean it manually. Dirty job but very safe for the engine.

Also try not to spray anything at the connecting points of the butterfly valve in the throttle body, it may mess up the mechanism that opens/closes the butterfly valve.

 

at 70k miles my heads look SUPER clean.



I really really doubt that at 50k miles enough carbon got stuck in your throttle body to cause idle mishaps.

your throttle body would have to be FILLED with carbon to get a funny idle.


I would be looking for vacuum leaks.

 

There is a very old TSB (service bulletin) 00-004, from 2001 concerning the 1999 3.2L EGR port clogging, which may be of interest in cleaning a later model TL's EGR.

 

Anything is possible, but I find it hard to believe that the throttle body is that dirty or that the egr valve is clogged with carbon. These cars are not that primitive. More likely is that there may be a sensor going bad. A common repair nowadays is to replace the mass air flow sensor. A faulty mass air flow sensor will make your car - any car - run like crap. In any event, if there is a real problem, there should be a code registered and a proper diagnosis will find the culprit.