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What do you recommend for cleaning intake valves on gdi engines?
2016 Hyundai Genesis 3.8

What do you recommend for cleaning intake valves on GDI engines?

(2016 Hyundai Genesis)
I have a 2016 3.8 Genesis Coupe with a GDI engine. I've read that on a GDI engine, blowback crankcase fumes and contaminants recirculated back through the PCV valve into the intake manifold, tend to carbonize on intake valves because with GDI, fuel is injected directly into the combustion chamber, not into the intake port above the intake valves - with no gasoline running over the intake valves to keep them clean and act as a solvent on crankcase contaminants, GDI intake valves tend to accumulate serious carbon deposits. Millions of cars today have GDI engines.

What is the best approach:
1) Take it to a shop or dealer for a total system cleaning (around $220 or more) every 20K miles
2) Go to Valvoline or Jiffylube for a 'fuel inection system cleaning (about $90)
3) Buy off the shelf products and do it yourself

Lastly, Is there any way to inspect the intake valves for actual need, and to assess post-cleaning effectiveness, such as some kind of endoscopic inspection?
What seems to make the problem better or worse? Car only has 22K miles; no symptoms yet
How long have you had this problem? Car only has 22K miles; no symptoms yet
Tags: gdi, intake valves, carbon, hyundai, genesis 3.8
2 answers & 3 comments
Popular Answer
on June 03, 2019

Sea foam - through intake plenum.

Google > Sea foam

Recommend *hands-on* assistance from qualified personnel for the application procedure.
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on June 03, 2019

Regularly scheduled engine service using Hyundai recommended oil and filters as well as recommended fuel type will certainly help reduce or even eliminate crankcase borne deposits..

Yes, there are a lot of direct injection engines out there.

Good luck and happy motoring !
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on June 03, 2019

Sea foam - through intake plenum.

Google > Sea foam

Recommend *hands-on* assistance from qualified personnel for the application procedure.
Sign in to reply
on June 03, 2019

Regularly scheduled engine service using Hyundai recommended oil and filters as well as recommended fuel type will certainly help reduce or even eliminate crankcase borne deposits..

Yes, there are a lot of direct injection engines out there.

Good luck and happy motoring !
on November 11, 2019
The carbon deposit issue on GDI engines was made popular by engineering flaws on Volkswagen and Audi engines. The injector was placed incorrectly within the cylinder which would in turn cause hydrocarbons to bake on the interior of the valves.

I haven’t heard of any complaints regarding the Genesis and carbon deposits yet. Also, I had a direct injection Mazda since 2007 with well over 100k miles, and I never had to do anything silly like seam foam the intakes or do an expensive inspection every 20,000 miles. It still ran as great as it did in 2007.

This is just a reflection of poor engineering and quality control for Volkswagen products. After all, almost all engines these days are direct injection. If carbon deposits were an issue, then why are all car manufacturers going in that direction?

Don’t worry, you’ll be fine. Don’t waste your money.
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on November 11, 2019

That’s interesting - I never really considered preventative maintenance to be “silly”..

I suppose it’s up to each individual owner to decide.

on November 11, 2019
What you say would be reassuring, if I didn't also see this:

https://www.gencoupe.com/2-0t-discussion-2008-2012/77810-why-you-need-catch-can.html#post854493

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