[CoupeSS]

My wife has a VW CC and has 140,000 miles on it, she has used ARCO premium gas 100% of the time since it was new. Her company pays for her gas with an ARCO credit card that's how I know she has only used ARCO. Anyway, it started running rough and fuel mileage dropped. The VW mechanics had to clean the valves, they said it was because she did not use Top Tier gasoline. I hope everyone learns from this. It cost me $1200. Below are photos of the valves.

[CoupeSS]

Another photo

[scandata]

Pretty nasty looking!

[JLBIII]

Hmm coming from a rep from a company just caught with emissions fraud

[Nessal]

Is her engine a direct injection engine? If so, not surprised. Has nothing to do with the gas.


Just looked it up. Yup not the gas fault. This is a known problem with direct injection engines. VW has some literature on this and people over at vwvortex has documented this through and through. This is a very common problem. In fact, her car is one of the worst and most known.

http://www.autoguide.com/auto-news/2...-engines-.html

Do a Google search, it's all over the web.

[clarkkent]

Originally Posted by Nessal

Is her engine a direct injection engine? If so, not surprised. Has nothing to do with the gas.


Just looked it up. Yup not the gas fault. This is a known problem with direct injection engines. VW has some literature on this and people over at vwvortex has documented this through and through. This is a very common problem. In fact, her car is one of the worst and most known.

http://www.autoguide.com/auto-news/2...-engines-.html

Do a Google search, it's all over the web.

Yup and BMW 335ci's are notorious for this as well. Unfortunately it is the easiest way for an engine to have 1) better throttle response 2) more horsepower and 3) better gas mileage. It's like the holy grail. Except, after 20k miles, you have to get your valves and runners sandblasted (with corn or shells or something).

So, Chevy's new LT1's (C7 Corvettes, 2016 Camaro SS) and LT4's (C7 ZO6) have direct cylinder fuel injection. We'll have to see if Chevy found a way to keep this from happening.

In a direct cylinder injection engine, it is way WAY more critical to have a catch can or something to keep oil particles from entering the intake manifold/intake runners. Because no matter what fuel cleaner you put in, it won't do anything at all but clean your fuel lines and injectors, won't do anything for the valves or intake runners.

[Mr. Wyndham]

Top Tier gas is a good thing to keep in mind when possible, but as has been stated - there are other factors at work here. I can't imagine "bad gas" alone would result in THAT much sludge. Not to mention that the fuel never sees the backside of the valves, anyways.

Unfortunately, it sounds as though the VW mechanics don't know how their own engines work.

Originally Posted by clarkkent

So, Chevy's new LT1's (C7 Corvettes, 2016 Camaro SS) has direct cylinder fuel injection. We'll have to see if Chevy found a way to keep this from happening.

In a direct cylinder injection engine, it is way WAY more critical to have a catch can or something to keep oil particles from entering the intake manifold/intake runners. Because no matter what fuel cleaner you put in, it won't do anything at all but clean your fuel lines and injectors, won't do anything for the valves or intake runners.

It has an integrated oil vapor collector on the valve cover side of the PVC system...but nothing on the plenum side. I will be curious to hear back from people after a hundred thousand miles have been put on some of these engines...But in the meantime, one thing's for sure...no matter how well Chevy engineered their new engines, as soon as I get a Gen Six, I'm putting a good oil catch can on the plenum side to try and prevent this...

[clarkkent]

Originally Posted by Mr. Wyndham

It has an integrated oil vapor collector on the valve cover side of the PVC system...but nothing on the plenum side. I will be curious to hear back from people after a hundred thousand miles have been put on some of these engines...But in the meantime, one thing's for sure...no matter how well Chevy engineered their new engines, as soon as I get a Gen Six, I'm putting a good oil catch can on the plenum side to try and prevent this...

Yeah I've heard of that being implemented in these engines, time will tell on how well they actually work. I wonder how well the "oil vapor collector" works. If it's just a series of baffles it doesn't seem like it will do much, but maybe it's more than that?

And yeah, good call on that

[Mr. Wyndham]

Originally Posted by clarkkent

Yeah I've heard of that being implemented in these engines, time will tell on how well they actually work. I wonder how well the "oil vapor collector" works. If it's just a series of baffles it doesn't seem like it will do much, but maybe it's more than that?

And yeah, good call on that

As far as I can tell, it's an integrated version of the same oil separator they put on the 1LEs. And that little thing grabbed a lot of oil, I've got to say. I'm certain their system works...Chevy engines, particularly their V8s are the best in the world for a reason...but my concern is that they only address the "clean" side.

[Welker2]

Agree with other's, there is something else at play here to cause that much damage.

[2013 ZL1 #7860]

Originally Posted by CoupeSS

Another photo

Direct Injection. The fuel has nothing to do with it as there is no fuel until AFTER the Intake Valves...

It being a VW with 140,000 miles is to blame.

[CoupeSS]

Okay, so everyone please explain to the dummy in the room (yes me) what this thing about a catch can is and what direct injection has to do with anything. You are talking over my head.

[Jackass]

Originally Posted by CoupeSS

My wife has a VW CC and has 140,000 miles on it, she has used ARCO premium gas 100% of the time since it was new. Her company pays for her gas with an ARCO credit card that's how I know she has only used ARCO. Anyway, it started running rough and fuel mileage dropped. The VW mechanics had to clean the valves, they said it was because she did not use Top Tier gasoline. I hope everyone learns from this. It cost me $1200. Below are photos of the valves.

So $1200 to fix it
I did the numbers , and if you had paid for the gas yourself for 140000 miles at 25 miles /gallon = to 5600 gallons , X $0,35 different between ( TOP) tier BS , and the lower shelf gas = to $1680 savings - $1200 to fix the engine , you still ahead by $480
Just take those $480 and take your lady for a nice Valentines Day dinner
You will be surprised what that can do for the two of you !

[ghosted]

Originally Posted by CoupeSS

Okay, so everyone please explain to the dummy in the room (yes me) what this thing about a catch can is and what direct injection has to do with anything. You are talking over my head.

In a Direct Injection (DI) Engine, the fuel is sprayed directly into the cylinder itself. The reason that top-tier gas doesn't do anything for carbon/gunk buildup on these valves is because the fuel never sprays across the valves. In Port Injection engines, however, this is a valid point.

An Oil Catch Can is a device that allows PCV gases to enter the catch can before feeding into the intake (and across the valves), allowing oil vapors to condense and collect in the can instead of down the ports, causing buildup.

With DI engines, the dirty vapors coming from the PCV system are leaving deposits on the valves, and there is no fuel being sprayed across the valves to keep them clean (fuel wash).