The head is done and will be picked up today (refer to thread Material Removal Limits for 16 Valve 190E Head?. I will have my sons remove the radiator to have it repaired at a local shop (new plastic water boxes and hopefully a better hose connection nipple), and get the engine ready to put the head back on. When we took the head off the tops of the pistons were pretty heavily covered with black ash-like stuff, most of which vacuumed out nicely. But there is still not metal showing everywhere. The cylinder bores are fine, except at the very top, for about an eighth of an inch or so, where there is a deposit of black stuff. Not thick, but a deposit.

The last time I did this kind of job it was on a Diesel and I just used some steel wool with some penetrating oil, like WD-40 to clean the guts out. There were no aluminum parts I was worried about that might be affected on that engine. What do you guys use?

Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Do not use ANYTHING steel to clean the piston tops. Any scratches provide an easy place for a crack to start. Scrape as much stuff off as you can with a hardwood stick. Once that is off, just wipe everything down with a solvent soaked rag.

BTW, you should be careful using a shop vac around the engine. If there are any gasoline fumes, the brushes in the vac make a great ignitor.

Good luck,

I agree with Larry.

Use a strong carb cleaner like Berryman B-12 and popcicle or paint mixing sticks. If it doesn't want to come right off, try letting it soak.

Tinker

Thanks for the advice. Will heed and take my time cleaning, avoid any scratches. Will post some photos next week. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Once the engine is back in operation, it will just "grow" back. Why disturb it? It's happy the way it is.

__________________
Norm in NJ
Next oil change at 230,000miles