# Carbon Build up on intake valves On monopoint engine (carb alike)



## Ferfire9 (Sep 11, 2017)

So a few days ago when taking my intake manifold out for a gasket change i saw that my intake valves were full of carbon, all of them. My engine has only 130 k km or something like 85k miles. Its 1600cc from 96 and is found on a lot of VW and Seat cars in Europe. If anyone can correct me, carbon build up was a direct injection thing ...not a port injection or throttle body injetion. My car is a mono motronic system, it only has 1 injector in the "carb" hooked to the throttle body. My intake manifold was prestine, completely clean inside but the valve intake part is terrible, full of carbon, and the worst thing is that i push this engine really hard almost all the time i drive it i redline it constantly and sometimes i bang the rev limiter...So i dont know whats causing that, and do you guys know any way to clean it? Looking at the internet i cant find a single article about port injection carbon build up, its strange as hell that my engine is full of it.

Some photos for you to check.


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## need_a_VR6 (May 19, 1999)

If there is no oil upstream, likely the valve stem seals are leaking a bit.


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## DbilasTDI (Nov 5, 2017)

http://bndautomotive.com/aces-formulas/aces-iv-gasoline-formula/


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## Butcher (Jan 31, 2001)

Does the engine have EGR? I do not see anything abnormal. When the valve guide seals are leaking, you will see oil on them. I do not see any signs of valve seal/guide wear.


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## Ferfire9 (Sep 11, 2017)

I am sorry for not answering sooner, i kept this post open daily after i opened waiting for replies and then droped it off since nobody answered.
This engine has not Egr. I made my research and looks like this is normal, so i just ignored it. To clean it, the best way suposedly is with walnut blast but i have no acess to such thing and its not worth it so...


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