My problem is that I don't know why the hell this is happening. We have a lot of cars sitting out there, and I'm afraid to start any of them now. This is--like I was saying--the second rotten case of this in two weeks.

If you'll forgive the long description, it's the only way I know how to explain what this is.

The fuel seems to lose some aspect of what keeps the formulation together, or keeps it "burnable", rather than turning into what looks and feels like almost-cured resorcinol. Over time, the reformulated gas takes on a really rotten, almost mildew-laden stink. In my chemistry-handicapped brain, it translates into something either: 1) breaking down/evaporating, or; 2) chemically reacting.

You can smell the stinky exhaust when you run a car with really old, stale Re-Formulated Gas (hereafter "RFG"). The problem seems to show up when the car spends extended periods at or near idle running on aforementioned "bad" (rotten) RFG. For example, we fired up a Trooper that was sitting forever, and used it to yank some non-running cars around the yard. It probably never got "hot" as it should've. If it had, it would've been fine (non scientific finding from driving cars with bad gas in them). Apparently the difference is in the temperature of the head rather than the quality of the gas itself.

What this tells me is that the RFG has some chemical component that comes unglued from the chemical formula and changes it's behavior while sitting. I don't doubt for a minute that it contributes to other maladies (aka valve stem deposits) on engines vulnerable to such things. Also it might have different reactions with dinosaur oil vs. synthetic, although that is just speculation.

The really bizarre thing is that the raw gas, injected into the intake plenum, leaves behind this gluelike substance. That varnish can't be cut with gasoline. It doesn't touch it. But carb cleaner removes it effortlessly. A no-touch solution to the problem.

Now that I think of it--since the head is off--I'm going to see if there's another formula that removes that goo. I'll just experiment with stuff tomorrow if I have the chance, and see if something will fix it.

I wonder if you can put carb cleaner into the gas tank? Never tried that. I'll experiment with other stuff tomorrow. It's hard to find an acceptable cleaner, though, because of the oxygen sensors. One would hate to foul them while trying to unfoul the valves.

But back to the fuel. It appears as if the gas actually breaks apart. Engines will run on bad RFG, but this varnish/sludge is like epoxy. In the case of this 740T, the intake valves are the real issue. One of them is locked so tightly that it stopped the camshaft from turning and caused the timing belt teeth to shear. I can't physically either depress or retract the valve, having removed the head from the engine. I yanked the camshaft and now I'm going to have to press out the valve and see what it looks like. From what I can tell, the sludge coked after the car was turned off (heat soak). It makes perfect sense.

The exhaust valves were sticky, but freed up easily after carb cleaner was shot on the valve stems. The intake valve stems clean well, but the sludge in the valve guides is so sticky that I can't move them. Hopefully I'll have time to pop out the intake valves tomorrow morning and see how they re-install after cleaning.

The engine itself showed some carbon deposits on the pistons, especially #2 (with a stuck intake and partially stuck exhaust). But nothing out of the ordinary for a B230FT. Clearly, idling the engine with old gas was not a good idea. The proper thing to do would've been to put fresh gas into it and drive it around. Unfortunately we couldn't manage that as the car had other issues preventing it from being driven.

From what I've noticed, especially in marine engines stored for 6 months at a time, the stabilizer really cuts down on the varnish and sludge from the gasoline. Also, you don't get the same musty smell from gasoline when it's been stabilized. There must be some chemical that prevents the breaking down of RFG especially. With regular unleaded gas, the problem might exist but is very minor. The RFG is the really bad stuff with respect to varnishing. I can tell if an engine has or has not been winterized, simply by looking at the throttle body/throttle bodies. Now this has shown that the gas stabilizer really does do a more effective job than I thought it did. Previously I thought that it just kept the gasoline at a certain volatility. Now there is obviously more.

What I'm searching for is a usable formula that will not only cut this varnish, but be acceptable for car engines. Marine engines aren't smog checked, so I can use things like ATF in the throttle body to clean them out. Finding something for cars will be more difficult, but if it cuts it on this engine head, I might just try running a bottle of it through another car as an experiment. Whatever substance it is that I find.

I'm not sure if this even answered anything, but I'm still trying to figure it out myself.