Cirrus8

There is so much concern about coking intake valves in the direct injection Corvette engines yet, I had a 600 hp, 14 litre diesel engine in my 18 wheeler that had a 500,000 mile warranty, was direct injected and never was coking of the valves ever a concern or problem. These engines will run in excess of their warranties. Why do Corvette owners fret over coking valves? Is this a non-problem looking for validation?

Oneslackr

I don't think most are losing sleep over it, especially since many don't hang onto their cars long term & end up upgrading on a regular basis.

Small world, I lived in Sandy 20+ years ago on Sunridge Dr., off of Newcastle Dr. which of course intersects Highland Dr. I loved being right at the base of the mountains between Big Cottonwood & Little Cottonwood Canyons.

MMD

Rebel Yell

I agree Cirrus. Coking was a big worry in Ford's new EcoBoost engines when they hit the market in 2011. The discussions were many on the F-150 forum. Now, nearly 9 years later some of those engines have close to 200K on them, and coking never seemed to be a problem. Yes it's ugly, but it doesn't worry me at all.

Steve_R

Because the OCD level is off the charts for a large percentage of C7 owners.

MMD

JerryU

This has been answered early re direct injection gasoline engines versus diesel re coking. First the LT1 was not the first to raise the issue as others had high performance engines with DI before Chevy. . BMW, Ferrari etc had high performance DI engines before the LT1. They not only reported problems some were using walnut shell blasting at 50,000 to 75,000 miles to remove it. See pic.

The difference in diesel and gasoline engine requirements for air flow are why, although it may exist in a diesel it does not create issues with flow. First the operating rpm's are usually much lower in a diesel than a high performance gasoline engine.. Flow restrictions become an issue only at high rpm.. Also most diesel's are supercharged. With enough pressure air can flow though somewhat restricted passages. In addition the crackcase ventilation system is different in a diesel but it still has to ingest the blowby fumes and "stuff."

The Chevy Chief engineer, Tadge says "It's just a cosmetic issue in the LT1." In fact if you never put your foot to the floor and get near redline you'll proably never know the difference.