I'm at the stage where I need to clean the block around the cylinder bores.
I was thinking of using a Scotch pad soaked in kerosene to remove debris. Dry it off and vacuum out the cylinders to get any debris that may have fallen in.

How have you cleaned the mating surfaces for a head gasket replacement?

The intake manifold and crossover pipe are still at the shop in the cleaning tank...DAY 4.

Is it safe to clean the head bolt threads on a wire wheel?

I have used wire wheels, scotch brite pads, and grinders... depending on severity of surface. most important thing is to verify surface bed flatness. you don't wanna introduce damage to the block that would hinder gasket contact. if you MUST reuse head bolts, a very sparing hit on the wire wheel grinder is ok, but I don't recommend reusing stretch to yield bolts...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

When I bought my metric Motor engine, it came with a lot of paper work. one was on gasket removal methods.

Please do not use rotary disc type scotch-bright surface prep pads (IE: Rolex, Whizzer) for removal of gasket material.
these pads, in conjunction with drill or die-grinder
*Will remove block or head material*
Particularly on aluminium, this will creat low areas and an
uneven surface. whicj will likely result in gasket failure.

The prefered method for gasket removal would be to use
a razor blade type scrapper followed by a flat surface
sanding pad (non-rotary type) or sharpening stone.

Per the following article from motor service magazine:

plug drain and supply holes punched in the gasket, inpede heat transfer. make a gasket stick andtear, or soften the gaskets surface enough to cause premature failure. In engine sealing, the mark of an expert is decidedly not a big wad of hardeded silicone squeezed out of every joint, but proper preparation of sealing surfaces.

Metal Mangling

Speaking of surface prep, the use of 3M style abrasive disks for cleaning then is an absolute no-no. Contrary to popular belief, even the new designs with the abrasive encapsulated in plastic are not safe and will destroy an engine.
Clearances are tighter today than ever befor, and even the slightest silicate contamination in the oil will wipe out a set of bearings. Plus, abrasive disks will remove significant amounts of metal. They`ll even do a job on cast iron (if you doubt this, grab an old rotor and your disc cleaning tool and lean into it - the flying sparks show you what`s happening) they are especially bad about removing metal from around holes> creating a concave depression. Use a scraper and chemical gasket removers.

I`ve done forensics on several destroyed engines over the years, engines that had had major work done on them shortly before losing the bottom end. in nearly every case, oil analysi revealed abrasives or contaminants.
An extra half hour of clean-up is a small price to pay compared to buying a customer a complete engine.

Iam just passing this on, take it or leave it, don`t yell at the messenger

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

I've always just used a scraper on the block, shaved the head- I mean what's $35 for a flat head.

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1984 123.193 372,xxx miles, room for Seven.

1999 Dodge Durango Cummins 4BTAA 47RE 5k lb 4x4 getting 25+mpgs, room for Seven.

Fortunately the aluminum head was just rebuilt and is very clean.
The block has the usual spotty collection of dark blobs.
It sounds like the main danger is getting abrasive contaminants into the oil supply holes and possibly the cylinders.

Based on your reasoned input, I'll use a razor blade type paint scraper, clean with cloth soaked in kerosene or acetone and vacuum the cylinders when done. Shapening stone? Would the stone leave abrashive material behind? Does the surface need to be shiny clean or completely devoid of surface foreign material?

Thanks.

I've done gasser headgaskets before, and the careful paint scraper(along with solvents) followed by a good shopvac job yield acceptable results.

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

Meh, i allways used the "flapper" disk on the disk grinder at work to clean off heads and blocks, 250 grit ground down to allmost nothing on a 1inch steel bench and then i go over the head/block lightly. Works great and shines it up nicely too.

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

flip the engine on the stand when scraping.

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Ive always used a razor blade. time consuming but seems to yield nice results. Be careful though, you'd be surprised how soft AL head is (if you have AL head...)

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Paul
Benz-less
I need an SDL !

ditto

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I've be at the block with a razor blade, acetone, vacuum cleaner, rags and a stone.

This is what I'm looking at. The squiggly line on the right is a piece of thread.

Do I need to remove the dark areas that appear to be below the height of the original machining marks?

Attached Thumbnails

   

Do a scratch test on questionable areas to determine staining from foreign material.

I would not be as concerned with that as much as the circumference of the cylinders / cylinder liners. These should be pristine.

P.S - is your crank out? -- why is the #1 piston twisted like that?

Confirm that there has been no impact to that piston (see the outer edge in pic #2) - the edges appear cleaner than the rest of the piston head.

And.. the center of piston head looks abnormal.

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what engine is this again?


edit: I am much more familiar w/ the 617 , 616 blocks. The rotation of the piston may not be an issue - I realize these engines had angled injectors / PCs.

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I am about to turn 60 years old... so I can talk about how things were done " in the old days"...

I am always worried when a rebuild is done without taking the engine block to be VATTED. This is a hot boiling out with everything which can be taken off the block taken off...
This was standard procedure in the old days... for every rebuild...
One area which is almost impossible to clean without vatting is the coolant cavity at the rear of the engine where flow slows down and lets junk collect... at some point affecting the cooling of the rear of the block and sometimes of the rear of the head depending on engine design.
Also, internal oil passages can need cleaning... often with a nice long wire brush... but I have seen times on old tractors where one needed to thread the available hole and use a grease gun to break out the obstruction...
Hate the idea of doing a great rebuild on all the rest of the stuff and still have unseen oiling or cooling gremlins lurking for some time in the future...

If I was doing a rebuild, I certainly would do as you say.
I'm replacing an original cracked #14 head on a OM603, with a rebuild #20 head. So my access is only from the top of the block.

The scratch test on the stained areas sounds good. I was going to clean it with clean acetone dampened rags until they picked up no more discoloration. Some of the stained areas appear to have very tiny corrosive pits.