The below should be cut from the danish Audiforum.dk - i hope it's just a hoax, but then on the other hand - you never know:

Hey guys, please help with my mods gone wrong.....

Hey guys, I've got a 98 1.8T. I've had a k04 and chip for a while and wanted to get more performance. I was recommended to port and polish the intake and exhaust. We found out they used abrasive material to do it like gritty sand. So I got with my friend that tunes Hondas and we decided to try it ourselves. We got a bag of sandblasting sand and hooked up into the intake and started the car. We had to hold the gas so it would run. He wanted to let the engine suck in the sand through the intake so it would port it out and then push it out the ehxaust so it would port the exhaust manifold.
I was worried that it might cause problems but he figured it'd be OK as long as we didn't make boost and it get sucked in the turbo. After running the car and letting it suck in sand we got about half way through a 25 lb bag. The check engine light was on and the engine was bucking and kicking and sounding really weird. We stopped and hooked the car back up normal and took off the sand supply. We tried to start it again and it was really hard. Once started it couldn't idle and kept making weird noises. We took it out and drove it and it started to make scraping and knocking noises.
Help! Can anyone tell me what to do! My buddy only does Hondas so he doesn't know much about Audis.

He used the wrong grit of sand. An Audi head is aluminum and more susceptible to galling. Whenever "powerporting" one should test the abrasive first to prevent this from happening.

Errm, am I getting something wrong here, Bill - the article I read on powerporting referred to taking the manifold off and sand-blasting it. http://autospeed.com/cms/title_Power-Porting/A_111154/article.html

The procedure above is going to fill the bores and rings with sand, his engine is junk.

This sounds like something my son did with a Corvair. Someone told him that pouring water into the carburetor would burn out the carbon so he ran the engine and poured water into the carburetors. The water cooled the steel valve seats, causing them to contract, and they fell out of the aluminum heads, ruining the engine.
Norm

Ouch, Norm.. But careful pouring a lesser quantity of water would probably have worked - if the engine was full of carbon in the first place. Few cars owned by younger folks for some time are full of carbon

Ok, Back in the 20's all cars needed frequent cleaning from carbon due to the kerosene infested gas of the time.

And in the 50's we smarty pants "knew" that is was a good idea to "open it up" on a long straight road to burn out the carbon! Oh boy, the engines that were ruined with that ill-advised method!
A shame we become too soon old, and too late smart!

I had read that post a couple years back.It is 1 of the most read forum post in all time .Right up there with the poor fellow that got Rinoliner on his hootis and was asking how to remove it.:>0

Dave, that's called an Italian tune up.

Several years ago, a friend of mine had a jeep that was burning oil, so he decided to run Ajax Cleanser through the carburetor to seat the rings.
It may have seated the rings, but it totally wiped-out the valve guides, making it burn oil worse than it had before, and run lousy too.

I'm having a problem here. It just seems really hard to read posts about anyone being stupid enough to pour sand in an engine. Or has all I've learned over the last 62 years been for naught? Every one knows you never do a "power porting" with sand. You always use valve grinding compound because it's important to grind the valve seats while porting. Sometime I can't believe you guy come up with this stuff. What if one of the guys new to the hobby reads your ill advice and uses sand. He could mess up a good engine. And think of the safety factor as well. What do you suppose would happen if some of the sand went into the fan and came back in his face. Your negligence is un-excusable. Always use valve grinding compound!!!!!

I always said there are people out there that should never be allowed to touch even small tools like screwdrivers or pliers but, this is the first time I ever thought there are some that should never be allowed to even OPEN THE HOOD!

I used to work at Electromotive (locomotive manufacturer), and they would use Bon Ami to scrub the cylinder walls if the engine had "souped-up" badly. Essentially this was to remove the varnish that could build up on a 2-stroke engine. Bon Ami was (is?) a very fine abrasive used for scrubbing pots. This worked on those motors, primarily because of the large wear allowance on the rings.

Sand in the intake????

ughhhh.

I drove Audi's for many years
Got 350K miles out of a 1989 200TQ, 250K on a 95 A6Q and about 225 K on a 96 A6Q Avant.

If you notice they went from 350K on the 89 to only 225K on the 96.
I didn't dare try a newer one!

I figure that if the Audi was a 2005 or so he was lucky to get it started

So, if I understand the above facts, I can power port any engine without disassembly but only if I use sand that is pre-mixed with water (not to much) and then follow with grinding compound to redress those valves?

Just think what a sand/water treatment would do for a T transmission, as long as you are treating the top end. Not to mention the power clean one could get of the block water passages and radiator by putting sand in the radiator top tank. I bet that would only work if you had a water pump as the thermosyphon would be soooo slow.

I've port & polished many sets of heads, but never by this method. It was always with burrs, die grinders & the like. Wow.

The bad thing is, I'm sure this is 100% true.

We extruded silicon carbide in a very heavy oil through passages to get a smooth flow path.
It worked great but we had a hard time finding a pump system that would not destroy itself.

Early ('50's) jet airplane engines (707 "Water Wagons")
used regular "tap" water injected into the engine to provide extra power for take-off....

Dave, NWA and JAL bought DC10-40s with water injected P&W JT8-9 engines. They soon found that Culligan (soft) water kept them working better.

All the rest of the DC-10 fleet had GE CF6.

Early 747 with JT8-9 probably were water injected, too.

Oops, not JT8-9; that is a light twin engine, like 737 and DC-9. The widebody Pratts were JT9-.