Cadillac CTS Engine Power Loss & Smoke: PCV Alert

Had a very similar issue with my 2008 Cadillac STS with the 3.6L engine. I have some experience working on these engines and immediately recognized these symptoms. The crankcase ventilation system malfunction was causing similar problems, smoke, power loss, and check engine light. The PCV valve was completely clogged, creating excessive pressure in the crankcase. This maintenance job required replacing not just the valve but also checking connected hoses and seals. The complete repair, including parts and labor, came to 360€. The workshop found that the valve failure had also affected other components in the ventilation system. The symptoms cleared up right after the repair, no more smoke, proper power delivery, and the check engine light stayed off. What engine variant does your CTS have? Also, are you noticing any oil consumption or rough idle? These details would help determine if your issue matches what I experienced. The repair complexity can vary based on engine configuration and how long the problem has been present. Worth noting that leaving a faulty PCV system unaddressed can lead to more serious engine problems and failed emissions tests. Regular maintenance checks help catch these issues early.

Last service was at 132000 KM. After checking my maintenance records, I can confirm similar symptoms started showing up around idle speed about 3 weeks ago. The crankcase pressure seems excessive, and the smoke gets worse when the engine is warm. The engine is a 3.6L V6. Oil consumption has increased lately, roughly 1L every 1000 KM. The idle is definitely rough, especially after the engine reaches operating temperature. The malfunction seems most noticeable during cold starts and when accelerating from a stop. The valve issue seems to match what you described. Will schedule a maintenance check to have the PCV system inspected based on your experience.

Thanks for the follow-up info. Your symptoms match my experience exactly with the 3.6L, especially the oil consumption rate and rough idle pattern you described. The timing also aligns, as these ventilation issues often show up between 130000-150000 KM. The increased oil consumption along with smoke during acceleration is a classic sign of crankcase pressure issues. In my case, the PCV valve was not just clogged but had actually started deteriorating, allowing oil to get pulled into the intake. When my repair was done, they found that the excessive pressure had also caused some seals to leak. The total job ended up including: New PCV valve, Fresh valve cover gaskets, Intake manifold cleaning, Oil change with filter Would strongly suggest getting it checked soon, as the oil consumption you mentioned is quite high. The complete repair resolved all symptoms, the rough idle disappeared, power returned to normal, and oil consumption went back to minimal levels. The 3.6L is generally reliable, but the ventilation system is a common malfunction point that needs attention around your mileage. Regular maintenance helps prevent these issues from causing more extensive engine damage.

Appreciate the detailed feedback and repair breakdown, this really helps confirm my suspicions about the PCV system. Given the matching symptoms and same engine type, I feel more confident about the diagnosis. Just scheduled an appointment for next week. The oil consumption rate you mentioned matches mine exactly, and knowing that your repair addressed all these issues is reassuring. Will make sure to have them check the gaskets and intake manifold during the maintenance visit since those were related problems in your case. The crankcase pressure symptoms you described are identical to what I'm experiencing. Learning that this is a common malfunction point for the 3.6L at this mileage explains a lot. Your repair cost seems reasonable considering all the components that needed attention. After seeing how the valve deterioration affected your engine, I understand why getting this fixed quickly is important. Will update my maintenance schedule to better monitor these systems in the future to prevent similar issues. Good to know the repair fully resolved the rough idle and power issues, those are my biggest concerns right now. Thanks for sharing your experience with such helpful details.