Mercedes-Benz Forum banner

Freeze plug - 83 300SD

2K views 11 replies 1 participant last post by  Guest (MBNZ) 
#1 ·
I need to replace the freeze plug on the driver's side of the engine. This is where all the injection/intake stuff is. Is there any way to replace the freeze plug without taking out everything that's in the way?<br> <br> If not, how complicated is it to remove/reinstall? I'm really good at taking things apart, but putting them back together...?<br> <br> Thanks for any help.
 
#3 ·
Sometimes called an expansion plug. There are several plugs, about 34 mm in diameter, each of which plugs a hole in the block. The idea is that if the coolant freezes, the plug will give way so that the block doesn't crack.<br>
<br>
That's how/why they come out. The trouble is, mine came out when the car was shut down for the winter and the coolant had been drained.<br>
<br>
Putting one back is simply a matter of driving it back in, with some sort of sealer/cement. The trouble is getting to it so that I can drive it back in. The injector module is in the way, and there's no room to get to the plug without taking off the injectors, which I'm hesitant to do. Taking it off shouldn't be a problem, but figuring out how it goes back on might be.<br>
 
#4 ·
Thanks for that. I think what you describe is also known as a Welsh Plug. Sounds like a bugger of a job ahead of you though, maybe a long weekend! Probably looks more difficult than it is though, and as long as you have some decent tools, you could maybe tackle it sucessfully. If you have a digital camera you could take lots of pics along the way. Have you got one of those Benz Manual CD's? <br> <br>
 
#5 ·
Sadly, no. I get my info from a Web site called AllData, which is quite helpful but not very complete. In addition, I've been thinking about but not carrying through on buying a digital camera, so the project, if successful, will have to be passed along through my not paltry descriptive skills.<br>
<br>
Geez, what is it about talking to an Aussie that makes me speak that way? I'm just an Indiana boy who's visited the Mother Country a time or two.<br>
<br>
Anyway, Welsh Plug is a cooler name, and 'freeze' is a word that MB owners in Wales and probably your part of Australia don't know as much about as we do around here.<br>
<br>
The 300SD hasn't been driven on a regular basis for more than two years, but before that I was driving it about 600 miles (you figure out the KM) every week. Short version: my son went to college and we didn't need three cars anymore. But I love the old boat, and this spring (fall, in your neighborhood) I decided to get it out of mothballs and start driving it again. That's when I found the freeze plug (Welsh plug) on the ground. I have no idea why it would've popped, because I had drained the coolant.<br>
<br>
In any case, I think my tools are adequate, and as soon as my cajones get to the same point I'll probably tackle the job. The worst that can happen is that I'll need to have the car towed to someone who knows how to put it all back together again. Maybe someone who has the CD.<br>
<br>
 
#6 ·
There you go again, 'fall' and 'cajones', but I get the drift (pun intended). Whew, you guys have a lot to contend with. We certainly wouldn't have to put the car into hibernation during winter over here. About all we have to do is make sure the coolant is up to the job, in case the temp falls a smidgen under 0 degrees. Most would not bother with new coolant as the summer fill would work well enough!<br> <br> Still, it intrigues me that the Welsh plug fell out though, even after being drained. Perhaps the block shrunk enough with the cold and popped it? I don't wanna know what the temp was when that happened - makes my bones ache!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top