Engine Question - not VX

[Joe_Black]

Carbon build-up is caused by poor quality fuel, and the United States has the poorest quality fuel (gasoling and diesel) on the entire planet. I take that back, Mexico has the worst fuel and we're the second worst.

Here's some info on carbon build-up that BMW was having an issue with on their E-series cars (courtesy BMWCCA):

Carbon Buildup was a common problem for the E28 535 caused by
poor fuel quality. Many BMW's experienced rough idle due to carbon buildup
while still under warranty. It is recommended you use premium gas at least
once in every 4 fill-ups. The premium gas contains more detergents to remove
the carbon deposits from injectors and gum/varnish buildup on valves. That
said however, some Oil Companies add no additional detergents to their
regular or premium fuel products... Ask your fuel company for information.

BMW North America undertook an engine campaign to pay for the removal of the inlet
exhaust and sand blasting to the back of the valves with crushed Walnut Shells.

Note that this issue was exclusive to North American cars, and the rest of the BMW fleet using the same engine had no issues.

In any case, there are some additives that can be used to help reduce build-up. I'm generally not a big propronent of "miracle juice" found at your local parts counter, but have been using LiquiMoly products in my diesels with great success. They have a product called "Ventil Sauber" specifically for carbon valve build-up in gas engines and I've received very positive feedback among various applications. You can sometimes get great pricing on eBay for their products if your local NAPA or auto supplier can't get it for you. LiquiMoly Web Site.

Good luck and just remember some engines are more susceptible to fuel quality than others, even among the same type. Especially vehicles with forced induction since the compression charge is higher.

[mbeach]

http://www.mercedes-benz-usa.com/c_class.php

That's all I'll say about mercedes-benz (not Capitalized on purpose).

[VehiGAZ]

I think my buddy was one of the posters on that page! Yeah - very poor quality in the C-class. Jeez, I had an early-in-its-first-model-year 1984 190E that was crappy, but not THAT crappy!

Here's something on fuel quality that I came across in Car & Driver recently:

http://www.toptiergas.com/index.html

[yal^]

Thx guys.
I think I will rationalize any sudden moves later.
I will keep my eyes open, but I am leaning towards BMW 330ix more and more...
For now I'll just sit tight and see how it works out. If it doesn't, my little kompressor is gone.