I recently rebuilt an engine, I started it a few times with my mechanic but we noticed that compression was too weak. So we fist tried playing with the hidraulic lifters. As compression problems weren't solved by this, I decided to take my car home and remove the engine head... again. I took it to a machine shop and they realized that the gas was mixed with sugar. They have cleaned it and have checked for little details and have my head ready to be installed again. Now, it is important that I didn't start the engine for a long time, around 5-8 miles only and for a few moments at the shop.

Now the crankshaft turns freely, no problems. I will use another intake manifold, airflow meter assembly with another fuel distributor.

My concern is... how do I propely clean the gas tank???

::

i guess you can either:

1. flush it by pumping gas in and drain it out at the gas line before the gas filter
2. remove the tank (filler neck, gas line, electrical sensor connection)

I imagine 1 is easier and should be good enough

Depends on how much water there was in the tank -- if a lot, you have a slug of sticky syrup on the bottom and will have to remove the tank and flush it. If it was only gas in there, no water, the sugar is still granular and you may be able to flush it out with gasoline, which is safer, but I would imagine you will still need to remove the tank. Make absolutely certain that you have only clean gasoline coming out of the supply line to the fuel distributor before attaching to a new one! Else you will fry that one, too.

DO NOT use gas line antifreeze to try to get it out, it will dissolve the sugar and allow it to mix with the gasoline, and THAT will fill the engine with carbon, not pretty.

Was the head full of glassy carbon? If so, I would also get new rings and pull the pistons and clean them -- that carbon will have very likely gotten down there too, and will cause the rings to seize, ruining the cylinder walls.

Get a locking gas cap to help prevent recurrances -- and make sure the filler door lock works, too!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Most radiator shops also dabble in fuel tank cleaning.

Gilly

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What everybody said is true, but using gas to clean the tank assumes that you will actually get all of the granules of sugar out. Not easy! I had to clean my daughters Rabbit once and I drained it, removed the tank, then used hot water to dissolve all the sugar, then flushed the heck out of it with a garden hose, followed by good long drying episode. I was then absolutely positive that it was free of sugar. No fun, but no worry either.

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