Project Smokey Wagon 2014! - Mostly just noob questions inside. W123 1985 300TD - Page 8 - PeachParts Mercedes-Benz Forum

Mölyapina · #1 03-16-2016, 06:21 PM

You are a brave man, these engines are grime magnets.

Also, I think yours is my favorite username on PP.

WarTowels · #2 03-17-2016, 10:49 AM

Haha! Thanks =)

I won't get it 100%, but I need to get it clean enough that I can spot where any potential oil leaks are. I want to fix the easy ones at least...

I installed the EGR delete last night after cleaning and I'm really happy with the extra room it's created. I'm tempted to pull out my non-functional A/C and Cruise control and maybe switch to a cone filter to really open up the cluttered engine bay. That would let me reduce the clutter quite a bit with no functionality loss. Toss everything in a box incase the desire to fix those bits arises.

In progress:

vwnate1 · #3 03-17-2016, 03:25 PM

FWIW ;

Before you go tearing the SLS apart , take the time to clean out the oil reservoir .

I discovered some boob had filled mine with ATF at one point and the bottom was still 1/4" thick with nasty looking slimy dirty grimy crud

.

It was a seriously fiddly job to clean it all out , then I replaced the filter and replenished it with the correct oil and it works fine .

As soon as the oil turns dark again (it uses a clear Mineral based oil) I'll go back in and clean it out again .

Oil and sweat are *MUCH* cheaper and easier than rebuilding the leveling valve , replacing the spheres and so on .

WarTowels · #4 03-17-2016, 03:52 PM

Quote:

Originally Posted by vwnate1

FWIW ;

Before you go tearing the SLS apart , take the time to clean out the oil reservoir .

I discovered some boob had filled mine with ATF at one point and the bottom was still 1/4" thick with nasty looking slimy dirty grimy crud

.

It was a seriously fiddly job to clean it all out , then I replaced the filter and replenished it with the correct oil and it works fine .

As soon as the oil turns dark again (it uses a clear Mineral based oil) I'll go back in and clean it out again .

Oil and sweat are *MUCH* cheaper and easier than rebuilding the leveling valve , replacing the spheres and so on .

Interesting. To be honest, this has been pushed way way back on the list of priorities. The car still rides quite well without the SLS system, no real complaints there. I have oil leaking out and some water leaking in- my two issues that are taking precedence. =)

vwnate1 · #5 03-18-2016, 12:22 AM

Well and good but always be proactive .

FWIW , you can take German vehicles farther apart than you can get parts , this means often you can actually FIX a thing instead of replacing it with some poorly made new part .

Mxfrank · #6 03-20-2016, 04:11 PM

You're overlooking another potential source for oil at the turbo, and the most likely based on your list of problems. The inlet of the turbo connects to the engine breather tube. There's not much flowing through the breather under normal circumstances. But with a hole in the pan and/or leaky engine gaskets, the breather becomes another source of air for the turbo. Drawing air through the crankcase also means drawing oil.

The turbo produces only 1 bar of pressure at full scream. Nominal oil pressure is 3 bar according to the gauge, but probably peaks at close to 5. So if you were dependent on hydrostatic pressure to oppose leaks, you would have quite a mess. The shafts and seals are designed to float on a film of oil, which is why they may seem to be a loose fit.

WarTowels · #7 03-20-2016, 04:56 PM

Quote:

Originally Posted by Mxfrank

You're overlooking another potential source for oil at the turbo, and the most likely based on your list of problems. The inlet of the turbo connects to the engine breather tube. There's not much flowing through the breather under normal circumstances. But with a hole in the pan and/or leaky engine gaskets, the breather becomes another source of air for the turbo. Drawing air through the crankcase also means drawing oil.

The turbo produces only 1 bar of pressure at full scream. Nominal oil pressure is 3 bar according to the gauge, but probably peaks at close to 5. So if you were dependent on hydrostatic pressure to oppose leaks, you would have quite a mess. The shafts and seals are designed to float on a film of oil, which is why they may seem to be a loose fit.

Mxfrank, I like your thinking but I believe I did rule this out with my latest test.

After cleaning up the manifold and turbo and running the engine, I had the entire stock air system disconnected and/or blocked off.

I plugged the crank case ventilation tube and the turbo was sucking filter-less. In this scenario the only source of oil to the turbo would be the turbo's cooling oil. And yet, I still had visible oil on the inlet side and oil being ejected between the manifold and turbo.

(I also plugged the ARV vacuum connection.)

Would an W124 Garrett T3 bolt up to the W123? I read they used a slightly larger trim, I think. There's a really clean one on fleabay for a reasonable price. Depending on what needs replacing on my turbo it seems like it could be quite inexpensive or equivalent to picking up this lightly used turbo. The big differences here being I could sell my turbo to recoup some money and avoid the cleaning and rebuild process on my current turbo. I am *sure* it has some carbon build up in need of cleaning.

ROLLGUY · #8 03-20-2016, 06:26 PM

Quote:

Originally Posted by Mxfrank

The turbo produces only 1 bar of pressure at full scream. Nominal oil pressure is 3 bar according to the gauge, but probably peaks at close to 5. So if you were dependent on hydrostatic pressure to oppose leaks, you would have quite a mess. The shafts and seals are designed to float on a film of oil, which is why they may seem to be a loose fit.

I am aware of that, and know that any oil that gets past the seals and bearings has lost it's pressure. It is a matter of the oil taking the path of least resistance. At idle, the oil will want to go past the seal and bearings (less resistance than the oil drain), but any added pressure (boost) should cause the oil to take the path of least resistance, being the oil drain. That is just how I see it in my case (Mitsubishi), but may not cross over to the turbo on a 617. The 617 may have more oil volume and pressure going to the turbo than the Mits, and that might explain the larger volume of oil getting into the intake at boost. Either way, a turbo rebuild/replace is in order.

Mxfrank · #9 03-20-2016, 07:28 PM

Quote:

Originally Posted by ROLLGUY

At idle, the oil will want to go past the seal and bearings (less resistance than the oil drain), but any added pressure (boost) should cause the oil to take the path of least resistance, being the oil drain.

Interesting. I wonder what the pressure characteristics are at the shaft. The compressor generates low pressure in the inlet and high pressure at the outlet. The shaft is right in the middle of the involute, which I would expect to be a low pressure area, but I could be wrong.

In this case, it looks as if the oil is coming back through the ARV. I bet if you remove the manifold and air plenum, you would find them drenched with oil, which makes it hard to identify the source.

WarTowels · #10 04-01-2016, 10:28 AM

Started taking the turbo center guts out but got stuck on one bolt. Trying to avoid buying Kent's tools to get it out, but we'll see.

Also started removing the oil pan and drain tube, only an hour or two in though.

I think I'm going to attempt to rebuild the turbo myself with a kit and see what happens.

vwnate1 · #11 04-02-2016, 09:01 AM

DO IT ! .

Only takes a few hours and makes a BIG improvement .

Ken's tools are handy but the picks he provides are near worthless ~ I tossed them in the trash .

It's important to be HOSPITAL CLEAN when doing this job and there's a lot of carbon crud in there you DO NOT want to get anywhere near the new bushings etc.

ngarover · #12 04-09-2016, 01:38 AM

Nice Turbo break down shot! That's one job I have not done yet myself. Your making really nice process with this wagon, would like to see more pictures of course, can never have too many.

I find these cars addicting. They are fun to work on and drive. Hopefully you get the point where your doing the later most! I drive mine about 20K a year and after 5 years still find it to be one of the most enjoyable cars I have ever owned even with it's quirks. The way your going this car is going to see another 30 years on the roads. As to your sagging rear, before you spend a lot of time etc, go ahead and get those rear subframe bushing replaced, they make a lot of difference. 123-350-03-75
1 SUBFRAME MOUNT KIT (Wagon subframe kit, Mercedes) The price is a little shocking, but you will be happy you did it. Mine drove like a different car after. Getting them in is a little tricky so search here for the instructions and read them a few times.

The difference you made with your interior carpet...wow. it's inspired me to do the same. what was the recoloring product you used?

WarTowels · #13 04-10-2016, 12:39 PM

Quote:

Originally Posted by ngarover

The difference you made with your interior carpet...wow. it's inspired me to do the same. what was the recoloring product you used?

Many coats of VHT vinyl and fabric dye, I believe in Dessert Sand: VHT SP961, VHT Vinyl Dye | VHT

Though I may be mistaken about the color. It's close-ish. (I recall there were two shades that were close and one was closer. YMMV)

Definitely lots of coats required if you want it to be more permanent. Do lots of light coats and in between each coat give it a complete brushing with a medium strength fingernail brush (or similar). This will help keep the fibers from becoming overly stiff and rigid. It will be stiffer than stock after all the painting, but it's not too stiff and worth it for the looks.

More turbo pics coming... thanks for reading =)

WarTowels · #14 04-10-2016, 02:35 PM

Almost ready to reassemble...

WarTowels · #15 04-11-2016, 12:02 PM

Spent all day yesterday continuing prep on the car. Wanted everything cleaned up so once I finished the turbo rebuild nothing would be in the way to finish the car.

I cleaned up the oil pan a bunch and prepped the block for a new turbo drain pipe grommet and new oil pan gasket. Cleaned up and turbo drain pipe and cold side of the turbo.

I had a little fun with the cold side of the turbo...