OM617 Block Drain Washer - Stuck to Block?

[JHZR2]

Wanted to drain my 300CD block, as the coolant has been in there for a decade (Rotella ELC, came out beautiful BTW).

Followed the DIY, was very careful with removal of the drain bolt. All went really well until I went looking for the washer. Now, I was and am conscientious of the washer. I removed everything gingerly, things went smooth, nothing fell, but no washer. I’ve since checked the drain pan, the ground, etc.

I think it’s stuck to the block. But I can’t tell. Certainly the opening on the block seems high, but no attempt to remove what’s there carefully was successful... and the last thing I want to do is harm those threads.

So what do you think?









This is with the plug screwed back in. Seems to me that the washer must be there by the look of it. I’ve never drained the block before so I don’t know what really is the case here...





Opinions?? Thanks!

[Diesel911]

If you don't want to try fool with removing the Washer wire brush the plug threads, and degrease it with Brake cleaner.

Get a tube of the non-hardening Peramtex, the old greenish or brown colored stuff and heavy coat the threads all the way up to and under the head of the plug. Install it normally and let the excess mush out and leave it alone.

Remember this is the stuff in the tube not the liquid stuff you brush on nor is it any sort of silicon sealant.

[Diesel911]

If you insist on removing what looks like an Aluminum Crush Washer get a propane or one of those small butane torches and heat it up and carefully use a pointed knife or a pointed thing like an ice pic to see if you can get under it and pry it off while it is still hot.
Replace it with a Copper Crush Washer. Harbor Freight sells an assortment and I also believe that places like AutoZone have them.

You can make your own aluminum crush washers from something like an aluminum nut can top but you can't just drill a hole through it without it getting ragged. You have to press it between 3 sheets of wood when you drill the hole. That way the hole comes out fairly clean. The nut can aluminum lid is thin enough you can cut the out side of it with a big scissors of for sure a sharp tin snips. The out side does not need to be round just so there is enough metal in the sealing area.

[JHZR2]

Originally Posted by Diesel911

If you don't want to try fool with removing the Washer wire brush the plug threads, and degrease it with Brake cleaner.

Get a tube of the non-hardening Peramtex, the old greenish or brown colored stuff and heavy coat the threads all the way up to and under the head of the plug. Install it normally and let the excess mush out and leave it alone.

I guess my first and foremost question to those who have done it before is....

Does it look to you like the washer is still stuck to the block?

It does to me, given the color and height off of the flat black raised block surface, but I may be wrong.

When I had bought the car in CA, it had Rotella OAT coolant. It’s the same coolant, about a decade old. Pristine clean and clear, but I’m going to JD Cool-Gard II as I want to use a consistent HOAT coolant for this and my 350SD (and 240D but that one has new fresh coolant in it) when I get the head gasket done. I’m concerned with coolant chemistry in that car, and believe that the Cool-Gard is the best choice for mixed metal engine designs like my 603. So anyway...

Anyway, that’s why I’m doing a series of flushes, and I’ll be pulling the plug again, perhaps a few times. I’m just not sure that I’ll be able to get the washer off if I want, but if my interpretation that it’s stuck to the block is wrong, I’d also like to know that....

[H-townbenzoboy]

I looked at Diesel Giant's writeup on flushing coolant, and if you scroll down to the picture of clear water being flushed through the block, you'll see the same thing that you saw. Might not be a washer. Have you looked at the EPC diagram to see if there's a washer?
https://dieselgiant.com/mercedes_citrus_flush.htm

[JHZR2]

Originally Posted by H-townbenzoboy

I looked at Diesel Giant's writeup on flushing coolant, and if you scroll down to the picture of clear water being flushed through the block, you'll see the same thing that you saw. Might not be a washer. Have you looked at the EPC diagram to see if there's a washer?
https://dieselgiant.com/mercedes_citrus_flush.htm

I reviewed that before posting on here, but no picture is good enough of a shot to show if the bright portion of the hole is raised as high as mine or what...

I guess in the end all, what’s the worst that’s going to happen? It seeps and then I address it further? Either double layer another washer or actually work to get the first one off... might need to remove the turbo to get to it sufficiently to do that!

[tangofox007]

The sealing ring is stuck in place. No doubt about it.

If you don't have a replacement or just don't want to remove the existing seal, spread a layer of RTV or pipe dope on the seal before reinstalling the plug.

[JHZR2]

Originally Posted by tangofox007

The sealing ring is stuck in place. No doubt about it.

If you don't have a replacement or just don't want to remove the existing seal, spread a layer of RTV or pipe dope on the seal before reinstalling the plug.

Thank you. Thought so, but additional eyes make all the difference in being sure.

I’ll be pulling the plug at least once more in the near term. Certainly not opposed to removing it, just need to be deliberate about the how, given that I’m doing it laying on my back on the ground with poor access.

Otherwise the recommendation for how to help it seal is also appreciated.

Thanks!

[JHZR2]

ELC coolants can really do well. Clean, clear, no sludge or dirt to speak of. I’m pleased.

[Zulfiqar]

Originally Posted by JHZR2

ELC coolants can really do well. Clean, clear, no sludge or dirt to speak of. I’m pleased.

The final charge brand is an ELC - most ford truck guys use that as it doesnt gel up in the EGR coolers on their trucks and the system remains sparkly clean.

sold at walmart for cheap - or NAPA.

[JHZR2]

Originally Posted by Zulfiqar

The final charge brand is an ELC - most ford truck guys use that as it doesnt gel up in the EGR coolers on their trucks and the system remains sparkly clean.

sold at walmart for cheap - or NAPA.

Yup. I’m pleased. I could have pursued a nitrite free (to protect aluminum) for my 123 and 126 cars. I found that I like the JD Cool-Gard II, even if a bit less ubiquitous. IMO it’s the rational step past G-05 (MB sheets have G-48 and G-40 now, so a HOAT with 2-eha, and a higher silicate POAT, iirc). The cool Gard seems like the ideal technological progression from G-05 to modern mixed-metal chemistry.

Don’t want to create a coolant discussion war, but that’s my findings/opinion/progression. But I agree, on a well flushed/clean system, the final charge type OATs are great for these cars.

[NZScott]

3 seconds with a screwdriver would pry it off. Amazes me what people ask for help about, but then I guess I was at that stage once upon a time

[JHZR2]

Originally Posted by NZScott

3 seconds with a screwdriver would pry it off. Amazes me what people ask for help about, but then I guess I was at that stage once upon a time

Three seconds with a screwdriver gouges the material that is there, and does NOT easily remove it, which is precisely why it was a question and concern.

Actually it was a right angle pick, on my back, essentially in the coolant.

Being cautious and asking effectively if what I’m looking at is a machined lip or a chemically adhered washer is better safe than sorry. I don’t have to be a bull in a china shop with this, there’s a reason these forums exist. Tangofox007 answered definitely; peanut gallery comments don’t help anyone.

[jabstick420]

i was in the same situation when i drained my coolant
checked epc diagrams, and there is a washer listed

it seemed cold welded on there, so i left it as is.
just snugged the bold back on and no problems, no leaks

i think the PN is 007603 038100

[Alec300SD]

On 'Stormcloud', I removed my stuck crush washer by using a hammer to strike a stiff putty knife
(3 inch width - angled about 10 degrees from the block) placed right at the edge of the crush washer.

IMHO, no harm in leaving it in place, so long as it doesn't leak.