Getting rid of the green stuff . . . crankcase drain plug location? - PeachParts Mercedes-Benz Forum

tankowner · #1 12-20-2007, 02:01 AM

One of the selling points that was used when I recently bought my '95 E300D was that it had just had a coolant system flush and refill. Unfortunately I have a system full of the green stuff. I picked up some Zerex G-05 the other day and would like to do a system flush and get the yellow stuff in there. Would anyone happen to know where the crankcase drain plug is to be found on this model. I haven't actually crawled around and looked yet, but I thought it would be easier if someone knew off the top of their head. I saw a post that suggested that some of the older 300Ds seem to have a plug somewhere near the fitting for the block heater cord. Is that the right place to look? Thanks!

turbobenz · #2 12-20-2007, 02:27 AM

I would just flush the radiator, then tie into a heater hose with one of those kits you get at the autoparts store, do a radiator flush then flush that out with a garden hose. Then fill it.

mobetta · #3 12-20-2007, 08:47 AM

umm- the crankcase plug is on the oilpan- but that is for changing oil, not coolant. block plug on a 617(sorry, thats what I know) is on the pass side under the block heater. 17mm? bolt. prepare for a shower.

I am sur esomeone else knows the exact location of your drain, and hopefully will post.

IMO, it is worth pulling, mabbeeee even a few times(flush), to get the crud out of the engine block.

vstech · #4 12-20-2007, 09:02 AM

acck
there is no need to use that cruddy flush kit. MB gives us 123 body style and 126 users a perfect location to hook up a hose. the heater system. and with power off, it's wide open.
I have no idea where to look on your model vehicle, but there should be a 17 or 19MM bolt head sticking out the side of the block just above the oil pan rail.

tankowner · #5 12-20-2007, 03:04 PM

Quote:

Originally Posted by mobetta

umm- the crankcase plug is on the oilpan- but that is for changing oil, not coolant. block plug on a 617(sorry, thats what I know) is on the pass side under the block heater. 17mm? bolt. prepare for a shower.

I am sur esomeone else knows the exact location of your drain, and hopefully will post.

IMO, it is worth pulling, mabbeeee even a few times(flush), to get the crud out of the engine block.

Well sure, the oil drain plug is on the oil pan, that I know. I would have probably called it the engine block drain plug, but MB actually refers to it as the "crankcase drain plug." Unfotunately the drawing they provide doesn't give a lot of clues as to its exact location. The crankcase itself (not the oil pan) does have coolant passages running through it too.

I do agree with you though that it is a good idea to pull this plug to get the crud out, which I don't think is entirely possible just by flushing through the radiator drain.

I appreciate your help. I will check near the block heater and let you know what I find.

tankowner · #6 01-08-2008, 10:15 PM

Thanks to everyone who replied to this post when I first put it up. I have finally done the job, but with a few delays. Here is how it went down. I picked up a new t-stat and rubber gasket before heading east for the holidays. Once I got a chance to work on it, I drained the coolant and unbolted the t-stat housing from the engine. Unfortunately, the old - and apparently original t-stat and gasket were really stuck in the housing. The gasket had just deteriorated and baked onto the housing. I peeled it out of there in several pieces, cleaned up the housing and then checked the fit of the new parts - problem.

Warning #1! Know exactly which part you need before yanking the old one. (This is the first rule of auto mechanics, right?)

The auto store sold me, not only the wrong gasket, but also the wrong t-stat. After searching a couple of more stores I finally found one who could show me a picture of the right gasket and t-stat.

Warning #2! When the parts guy tells you that the part will shipped there within 2 days, add on 2 more days so you won't be disappointed when it doesn't show up. (This is the second rule of auto mechanics, right?)

Anyway, The right parts finally came in. I slapped it all back together, drained out the green stuff, filled it up with water and ran it down the road a while, drained the water and filled it with 50%/50% distilled water and Zerex G-05.

Oh yeah, the crankcase (engine block) drain plug is located next to the block heater cord connection on the passenger side of the engine. You can attached some rubber tubing to it so as not to take a coolant shower during the process.

I decided to take pictures of this seemingly simple operation that I am going to post in the DIY section. It is an easy job, but if others can avoid these little pitfalls, then I will be giving back at least a little of what I have gained from this forum.