GregMN's 1991 W126 350SDL Has A New Home - Page 12 - PeachParts Mercedes-Benz Forum

Squiggle Dog · #**166** 11-14-2019, 09:41 PM

Thanks for the kind words! Unfortunately, there really isn't any space here to work on other peoples' cars, and it's just too darn hot. I'd really need an air conditioned shop.

Squiggle Dog · #**167** 11-14-2019, 09:55 PM

The ALDA went bye-bye. If it's not necessary, rip it off, I always say.

The EGR housing was really corroded and nasty looking. I soaked it in oxalic acid, which cleaned it up nicely. Yes, I also ripped out the EGR valve.

I also ripped out the ARV transducer and capped off the ARV and vacuum tube. Get this crud outta here!

The injection lines were worn from years of use without being secured by clips. At some point they should probably be replaced.

The plating on the injection lines was gone and they rusted quickly, so I painted them. I got frustrated because I couldn't figure out if the injection lines or the intake manifold should go on first. I ended up having them on and off a few times until I got the parts in place. I kept having to reroute the engine wire harness as well. Such a hassle!

Squiggle Dog · #**168** 11-14-2019, 10:08 PM

This car is kind of a hodge-podge. It has the heater pipe from a W124 300D which also has a fuel heater (you bet I ripped that off) and so the bracket that holds this connector didn't fit anywhere, so I had to cut it to fit in a different location. The connector here crumbled apart, so I replaced the broken connector half. Sadly, as soon as I snapped them together, the locking arms of the other half broke off.

After much guessing and toil I got most of the exterior parts of the engine assembled. The wire harnesses required manipulation with a heat gun. Sadly, all of the plastic clamps that secure the wire harnesses have broken off. I ordered replacements, but they were too small and supposedly superseded the larger ones? So zip ties had to do.

Installing the plastic injection line clips was so difficult! The more I work on this engine, the more I like my OM617. Sadly, there are some wire harness brackets missing, but oh, well.

All of the vacuum hose and connectors in the engine compartment were rotten and crumbling, so I replaced them with new ones.

Squiggle Dog · #**169** 11-14-2019, 10:27 PM

Here is the mass air flow sensor (MAF)/air flow meter (AFM), which "lives" between the air cleaner and turbocharger. I didn't like it, so I ripped it out. It has a door inside which gets sucked open when the engine draws in air, but they can stick and choke the engine. I also suspect it might delay acceleration.

Here is its replacement--a $7 exhaust pipe extension from O'Reilly Auto Parts. One end of it is 3" in diameter, and the other end is 3 1/8" in diameter, which is close enough to the size of the part it's replacing, which has ends that are different sizes. I cut it down to 185mm or 7 1/4" long to match the length of the original part.

I robbed the nuts from the ARV vacuum transducer to use on the frame of the mass air flow sensor...

...to hold it together with the mass air flow sensor removed from it. This is needed as it's also the air cleaner mounting bracket.

vwnate1 · #**170** 11-15-2019, 09:25 PM

You say you ripped it off, what did you do to stop the flow of exhaust gas ? .

Squiggle Dog · #**171** 11-15-2019, 10:07 PM

Quote:

Originally Posted by vwnate1

You say you ripped it off, what did you do to stop the flow of exhaust gas ? .

I put an EGR valve delete plate on it: GregMN's 1991 W126 350SDL Has A New Home

Squiggle Dog · #**172** 11-17-2019, 11:33 PM

I cleaned the inner fender while the parts were out.

The coolant reservoir hose bracket was broken off. A new one was only 51 cents!

The air cleaner bracket got soaked in Evapo-Rust and painted. One of the rubber isolators had broken, so I epoxied it back together.

Here is the delete pipe I made to replace the mass air flow box.

The hose clamps for the air cleaner and turbo boots were very rusty and pitted, so I removed the rust and painted them.

Actros617 · #**173** 11-18-2019, 05:29 PM

Where did you get your EGR block off plate and the ADLA cap?

ROLLGUY · #**174** 11-18-2019, 09:38 PM

Quote:

Originally Posted by Actros617

Where did you get your EGR block off plate and the ADLA cap?

Check out my signature. I have the EGR kit available. Not sure about the ALDA cap.

Squiggle Dog · #**175** 11-18-2019, 10:17 PM

Quote:

Originally Posted by Actros617

Where did you get your EGR block off plate and the ADLA cap?

Yeah, ROLLGUY here sells the EGR delete kits. It's funny because I bought one from someone else on eBay years ago for my 300SD, and then my roommate bought one from ROLLGUY for this car. The one from ROLLGUY got lost in a box somewhere when we moved and we couldn't find it, so we robbed the one from my 300SD because I had just replaced the manifolds with non-EGR ones. I remember the one that ROLLGUY sold had that nice yellow cad plating that matches the rest of the plated parts on the vehicle. One day it will turn up.

As for the ALDA cap, we got it from this guy:

https://www.ebay.com/usr/dynomatt27-7?_trksid=p2047675.l2559

https://www.ebay.com/itm/mercedes-300-om617-injection-pump-alda-delete-/174043166450?nma=true&si=qOf9oBwuxTVMn9zfA44YOcMZpJM%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

Squiggle Dog · #**176** 11-19-2019, 10:12 PM

The two valve covers we have didn't look very good. The one that came with the head was in the worst condition cosmetically.

So, I decided to sand and polish it. I used 400, 600, 800, 1000, 1500, and 2000 grit sandpaper that comes in little strips in the packets at the auto parts stores, and soapy water. It took about 10 hours. Then I polished it with Blue Magic Metal Polish Cream. I let the polish set on the surface for a couple hours to clean off the oxidation from the pits and depressions. It's not perfect, but it does look better than new. This is not a job for the lazy!

Here is the polished valve cover installed with a nice oil filler cap.

I installed the air cleaner, support bracket, and pipe.

Squiggle Dog · #**177** 11-20-2019, 09:01 PM

It seems that most of the internal breather valves which are hidden away inside the baffling which is riveted in place under the valve covers of the OM603 engines are failing by now. Mercedes must not have intended for the engines to last this long. Their solution is to buy a new valve cover (603-010-05-30) at $615.00.

When this check valve fails, the turbocharger will start to suck in oil from the engine and coat the intake manifold with oil. I wonder how many people have rebuilt their turbocharger thinking it was the culprit. See this link for more information: https://www.coolcatcorp.com/Mercedes%20valve%20cover/Mercedes%20Valve%20Cover%20Breather.html

Apparently you can tell if the internal check valve has failed by putting a hose up to the little hole on the right rear of the valve cover and draw a vacuum--if oil comes out, the diaphragm has failed. On both the valve covers I have here, the holes are wet with oil. I just did a head replacement on this car with the one from the Diseasel after it met its demise. It came with a valve cover, and before the head swap, the previous valve cover on the car on which I am working was allowing oil to get sucked into the turbo as well.

I noticed Diseasel300 had installed a PCV valve from a 1999-2004 Volkswagen Golf or Jetta diesel to replace the failed diaphragm inside the valve cover: The "Diseasel" - '86 300SDL

I decided to get a Volkswagen PCV valve. I was reading this thread here: 0M 603.971 Cold Starts, right up Then: and clicked on the link and purchased a similar PCV valve. Then I realized that the valve I purchased (part number 06A129101D) is a different one than what Diseasel300 used (028129101E) and is actually for a gasoline-powered 1.8 liter Audi and Volkswagen. Oops.

Sadly, while the one I ordered seemed that it would be even more ideal than the one Diseasel300 uses, the bottom tube was too thick to fit into the grommet. It was nearly the thickness of the hole in the valve cover. Darn it! So, my roommate ordered the correct one and the grommet that goes with it since it keeps the valve from resting on the valve cover.

Here is the 028129101E part number valve with the matching 028103500 part number grommet.

The pin on the side should be snapped off so it doesn't interfere. Diseasel300 also inserted a barbed brass fitting on which he shaved off the threads and inserted with black sealant so a smaller hose would fit on it.

This is how the grommet fits on the valve cover--tall side up!

Here is how the PCV valve looks on the valve cover. Unfortunately, it points in the wrong direction and can't be rotated without obscuring the oil filler cap. I tried to think of elegant ways to route the hose so it would be secure and wouldn't interfere with the belt tensioner access or removal of the fan. I even considered using 5/8" aluminum A/C tubing and bending it to shape and securing it to the front of the head using spacers and clamps.

Squiggle Dog · #**178** 11-20-2019, 09:10 PM

But then I had a breakthrough! I figured out a way that I could use this 06A129101D part number breather valve after all.

Because the Volkswagen grommet is so tall, a large portion of it is on the outside of the valve cover, allowing it to expand without the valve cover restricting it. I found that if I cut off the flare at the bottom of the valve, the grommet would stretch enough for it to be inserted.

Squiggle Dog · #**179** 11-20-2019, 09:22 PM

I had an old breather tube on which the insulation had deteriorated, and a fairly new one.

I cut off the part that fits into the valve cover on the old breather tube. The tube is wider on this end due to the plastic fitting which was inserted, which also adds strength and makes the outer diameter of the tube closer to the fitting on the breather valve.

Then the insulation from the newer breather tube was slid over to connect the tube to the valve--which has the grommet attached to it. Due to adding the breather valve on the end, the tube was now too long, so I cut off about 1 1/2" from the bottom.

Then I slid on the grommet and lower piece of insulation.

I am very happy with the new breather arrangement. It looks original and does the job without getting in the way of other parts.

Squiggle Dog · #**180** 11-20-2019, 09:29 PM

The 350SDL is alive again! It idles smoothly and seems to have decent power. I don't notice any smoke unless I have it floored (and then it will roll coal quite well).

Right now there is oxalic acid in the cooling system in order to get rid of the rest of the rust in the block. Then it will get washing soda and a good rinse before the Zerex G-05 coolant goes back in it.

I had to rip off the hood pad. It was saturated with oil and sagging down. No glue would hold it and even after my idea of holding it up by wedging in popsicle sticks, the center still sagged down too low. It kept getting the engine compartment dirty and scuffing up parts. I couldn't deal with it anymore. Hopefully the paint on the hood doesn't fry.

Here is how the engine looked when he got the car.