GregMN's 1991 W126 350SDL Has A New Home - Page 2 - PeachParts Mercedes-Benz Forum

Squiggle Dog · #16 09-25-2018, 02:24 AM

The tips weren't swollen very much, but it only takes a very minute amount to get stuck, especially if there is a lot of carbon in the hole. Only one of the plugs was a Bosch. The rest were the Autolite type. The Bosch plugs have a tapered tip which resist swelling much. They also don't burn out as quickly.

Autolite on left, Bosch on right.

Engine being worked on.

There was a large fuel/waste vegetable oil leak at the injection pump delivery valve O-rings.

I installed new Viton O-rings.

Squiggle Dog · #17 09-25-2018, 02:36 AM

I got the engine put back together with new biodiesel-resistant hoses. I straightened out the fuel lines and installed new plastic clips. I also disabled the ALDA.

Squiggle Dog · #18 09-25-2018, 02:52 AM

It was going to be the day I would reap the fruits of my labors. I put some diesel purge in a can and cranked over the engine. It took lots and lots of cranking until finally the fuel started leaking down the tops of the injectors. I tightened up the hard lines and then cranked over the engine.

It sputtered a bit and finally started to run. Then it sputtered again and the engine locked up. It seemed to be seized. I saw dark fluid running out from underneath the car, but all of the hoses were dry. Odd. It appeared the fluid was coming from the front crank seal, the gasket on the side of the oil pan, the exhaust pipe clamps, and between where the injection pump meets the block.

Then I checked the dipstick. It was extremely overfull with a very thin liquid. It smelled like diesel purge, yet less than half a can actually was sucked up.

I removed the injectors and could see that the #2 cylinder was full of diesel purge. So it was hydrolocked. I'm not sure about the other cylinders, but the #2 was near the top of its stroke, so that one was obvious.

I cranked over the engine and it turned freely, shooting out diesel purge all over. So, at least the engine wasn't seized.

I put the injectors back in and cranked the engine with the hard lines disconnected to prevent hydrolocking. I cranked and cranked and cranked the engine, but only a tiny bit of fuel was coming out of the #5 and #6 hard lines. The rest were dry. The pump was sucking fuel out of the can, but not much of anything was coming out of the hard lines.

Then I noticed that fluid was overflowing out of the engine oil dipstick tube. I opened the oil filler cap on the valve cover and there was standing fuel draining down into the crankcase. The fluid on the dipstick was the same color, consistency, and smell of diesel purge and diesel.

Squiggle Dog · #19 09-25-2018, 03:02 AM

I drained the crankcase and filled up a 2.5 gallon container to the brim. I then checked the oil level, and it was at the MAX mark on the dipstick. So the crankcase was 2.5 gallons overfull! I drained out another 2 gallons to empty the crankcase. It smelled like diesel/biodiesel/purge.

The crankcase was at least an inch over the MAX mark on the dipstick tube before I ran the diesel purge. Fuel must have been leaking into the crankcase before I ran the purge. The last time I drove the car, there was almost no throttle response, and it kept getting worse and worse.

I removed the lift pump for inspection. I could see residual fuel running out from the fitting on the back. When I opened it up, O-ring #261 was completely missing. So there was nothing but the threads separating the fuel from the engine oil. The machined faces didn't even meet up and there was a small gap between them due to the threads ending.

The parts, like the rest of the fuel system, were gunked up with grit and congealed waste vegetable oil.

The valves seeed to work. I can't imagine one ever failing even if the spring were to wear out because it just keeps fuel from draining back into the tank and fuel pressure will push it in either direction. They are cheap enough to replace, but one of them is pressed into the fitting and may require drastic measures to remove.

O-ring #258, which also separates fuel from engine oil, and which the pushrod passes through, was severely worn on one side. This one must have been leaking fuel past it. It's green. Does this mean it's made of Viton?

So, it seemed that missing/worn O-rings in the lift pump were the cause of the fuel entering the crankcase. I put in 2 gallons of 15W40 diesel oil, then installed the rebuilt lift pump, but it would smoke grey smoke. I took the car for a drive around the block, and it was spewing grey/black smoke like a freight train.

So then we had the injectors rebuilt. I checked the engine oil level, and it looked fine. After bleeding the fuel system, I went to start it. BLAM! Fuel shot out of the intake manifold seams and soaked the right fender. But, it was running. Still smoking just as bad, though.

Then after I shut down the engine, I waited for a while and checked the oil. The oil level was way too high again, and watered down. It smelled like fuel, so it was STILL getting into the crankcase!

With the 350SDL having no reverse, in need of brakes, having bald tires, the air conditioning no longer blowing cold (and we live in Phoenix, Arizona), and now with it possibly needing an injection pump, it seemed it was going to be too expensive to continue on with the project.

Squiggle Dog · #20 09-25-2018, 03:26 AM

Meanwhile, my roommate found a set of good fenders in Arctic White at the wrecking yard, so we pulled off the SDL's rusty front fenders and found there was some bad rust at the left side fender mounting area.

Squiggle Dog · #21 09-25-2018, 03:31 AM

He ordered a new Klokkerholm left rocker panel, I cut out the rusted area on the car, and cut out what was needed from the new rocker. Of course, the end of the rocker we needed was bent and folded during shipping.

He hired someone to weld on the rocker section, and I did the rest.

After some grinding and rust converter.

Squiggle Dog · #22 09-25-2018, 03:46 AM

Some filler.

Primed and painted.

Fenders installed. They had painted-on pinstripes that my roommate spent hours removing.

Squiggle Dog · #23 09-25-2018, 04:25 AM

I took the injection pump in to Southwest Diesel & Electrical, since on their website they advertise that they will test an injection pump for free because they are one of the few shops around that still has the old Bosch test equipment. When I went to pick it up, it was completely taken apart in a box and they said, "That will be $100."

I asked why they were charging $100, and they said that they had to take it apart to see if it was bad. I told them that I had stated I wanted it tested for free on their machine. They told me they don't have that equipment anymore, but the pump is bad.

I asked them what specifically was bad about it, and they said they couldn't tell me, but then they finally had the guy who took it apart tell me the pump was "in very sad condition" and that the plungers and bores were very scored. He quoted me $2,450 to rebuild it. I should have just left it there.

This is the same shop that rebuilt the injectors on my 300SD and I had to take them back about four times because they didn't clean them properly and so they were leaking between the upper and lower half of the body, all the while their mechanic was telling me it was my hard lines or return hoses (which it wasn't). They also told me that the pressures on injectors don't really matter, because "if they pop, they pop".

So, the injection pump was leaking fuel from the fuel chamber into the oil chamber at a high rate because of worn and scored plungers. The waste vegetable oil was likely coagulated and working as a seal, causing premature wear and masking the problem; and once I did the diesel purge, it cleared it away and allowed free passage.

It was dumping more fuel into the crankcase than was actually going into the injectors. It put over 2 gallons of fuel into the crankcase in short time. This caused excessive crankcase pressure which blew out the manifolds.

I had to convince my roommate that a replacement injection pump would solve the problem. I searched around and dieseldiehard came through with a pristine, recently serviced pump for a bargain. I don't think he could have gotten a nicer used one at any price!

The vacuum control valve was missing the rubber elbow, and I think they are no longer available. O'Reilly Auto Parts had one that fit.

The injection pump was installed and works great. The old injection pump was certainly the problem.

This opportunity was taken to update the vacuum pump, as the bearings were worn and one of the balls had cracked.

Squiggle Dog · #24 09-25-2018, 05:01 AM

Our landlord suddenly gave us 30 days notice to vacate the house because the owner was putting it up for sale, so my roommate and I had to find a new place to live, pack, move, and clean the house within that short time. It was stressful, but the 350SDL was driven to the new house in Surprise (with no reverse).

At the request of my roommate, I completely removed the waste vegetable oil system from the car and gave it back to Greg. He was visiting Payson, Arizona, and I happened to be delivering a truck load of Amazon packages to the post office there, so it worked out well.

Later on I was transporting refrigeration equipment to a restaurant in Oakland, California and stopped by dieseldiehard's place. He said he had a good (possibly rebuilt) transmission from a W126 350SDL that was in the way, and he said I was welcome to it. After I got home and inspected it, it turned out it was from a W124 chassis and wouldn't fit. There must have been a mix-up with the one he thought he had, but I really appreciate the gesture. I ended up passing it on to someone who needed a rebuildable core.

With that development, I decided I might as well just fix the reverse clutch pack in the original transmission. So, I made some wheel cribs so removing the transmission would be easier.

Ratcheting straps keep the wheels from rolling off the cribs.

rocky raccoon · #25 09-25-2018, 08:02 AM

Quite an story Squig. I am thoroughly impressed. I guess you have already discovered that running anything but Diesel in our Diesel engines is a long-term heartbreak.

Hope you-all are resituated.

cad58y · #26 09-25-2018, 09:08 AM

Where did you get your spacers for the wheels? Thanks

barry12345 · #27 09-25-2018, 11:46 AM

Spacers and wheels are a real issue that should be subject to some study. By any person considering the use of them. You can change the front geometry as designed by using them for one thing. Offsets are important.

Basically if you draw a line through both ball joints. If should intersect the center of the tire tread. Plus it is best to maintain a center of the wheel support. Failures of spacers have also been too common to ignore.

Squiggle Dog · #28 09-25-2018, 01:35 PM

Quote:

Originally Posted by rocky raccoon

Quite an story Squig. I am thoroughly impressed. I guess you have already discovered that running anything but Diesel in our Diesel engines is a long-term heartbreak.

Hope you-all are resituated.

I am a big believer in biodiesel and have been running it in my 300SD for about eight years. It lubricates better than diesel so the parts last longer, it keeps the fuel system cleaner, it gives more power, it burns cleaner, and is a renewable resource.

But, I agree with waste vegetable oil's potential to cause problems, even though I like the concept of it. I also don't think running on used engine oil or transmission fluid is good for the vehicle.

Quote:

Originally Posted by cad58y

Where did you get your spacers for the wheels? Thanks

My roommate got them on eBay a few years ago.

Quote:

Originally Posted by barry12345

Spacers and wheels are a real issue that should be subject to some study. By any person considering the use of them. You can change the front geometry as designed by using them for one thing. Offsets are important.

Basically if you draw a line through both ball joints. If should intersect the center of the tire tread. Plus it is best to maintain a center of the wheel support. Failures of spacers have also been too common to ignore.

We thought installing CLK wheels would be simple, but it turns out the grease caps on the hubs were sticking out of the ends of the wheels, and the offset was different. The wheel spacers we used corrected the offset and made it so the little wheel caps would fit back on.

But, I would rather have not used wheel spacers if they weren't needed for these wheels to work.

Squiggle Dog · #29 09-25-2018, 09:26 PM

I removed the transmission and slid it out from under the vehicle.

I took the transmission apart and everything inside looked great except for the reverse clutch discs, which were worn down to metal.

I was removing one of the piston covers and it flew off with so much force that it hit me in the face, hit the ceiling, then landed a few feet away. I'm lucky I wasn't hurt worse. Gotta be careful of those two big springs they put in there!

Biodiesel, oven cleaner, and aluminum polish with a wire brush cleaned up the transmission housing quite well. Assembling the transmission was quite a learning process and it was hard to keep contaminants like dog hair out of it.

I ended up having quite a problem; the valve body parts got mixed up and I couldn't figure out where all the springs went. I looked up images of 722.3 valve bodies, but the valve body for each model of car is different and there seemed to be no pictures of a valve body for a 722.361 transmission.

I figured that I would either have to buy a new valve body from Mercedes (as used ones seemed to not exist) or guess and put the springs where I thought they would go. I put the valve body back together according to my best guess, and the transmission worked as it should, including reverse. Not bad for my first transmission rebuild!

79-240d · #30 09-25-2018, 10:22 PM

Quote:

Originally Posted by Squiggle Dog

the transmission worked as it should, including reverse. Not bad for my first transmission rebuild!

Incredible! Great work!