Intake valve maintenance?

[sherlla]

Has anyone done a intake valve maintenance at the dealership to prevent carbon deposits or DIY themselves. I'm hitting 30k miles soon and was wondering if anyone has considered it. Im trying to avoid it getting so bad that walnut blasting is the only option.

 

[haohmaru]

Have you checked them with a Boro scope? I'm curious how much or if any. Carbon buildup speculation has been a source of contention on here lol.

 

[Howdog70]

Bore scope

 

[sherlla]

Have you checked them with a Boro scope? I'm curious how much or if any. Carbon buildup speculation has been a source of contention on here lol.

Carbon deposit happens over time and I'm sure I don't have much, I'm just trying to remove any now before more forms. I've heard that arosol cleaners are recommended to use to clean every 30-40k miles to prevent caked carbon at higher miles. I drive alot so I know I'm going to be hitting 100k in like 3 years. Asking for anyone's experience on this matter.

 

[RHE2026]

Does your car have an oil catch can installed? I have been curious about keeping those valves clean as well. The direct injection engines are prone to carbon buildup on the valves unlike the fuel injection 350 Z I owned where the fuel reaches the valves and the detergent cleans them.

 

[KrackaC8]

TopTier+ certification now includes a DI intake valve cleanliness test.

https://www.toptiergas.com/wp-conte...eposit_Control_Performance_Standard_Rev_H.pdf

https://www.toptiergas.com/2026/05/26/top-tier-announces-new-top-tier-standard/