The "Diseasel" - '86 300SDL - Page 5 - PeachParts Mercedes-Benz Forum

vwnate1 · #61 05-14-2017, 01:22 AM

I was harvesting parts off a 1982 560SEL to - day and some one had removed the dashboard with a crowbar (of course, it had been *perfect* and they destroyed it

) and saw the AC's expansion valve tucked way up against the firewall behind some harness and decided to see just how bad it is to remove ~ wow, not easy .

Your car is coming right along ! .

Diseasel300 · #62 05-14-2017, 09:41 AM

Getting the expansion valve OUT is the easy part. Getting it back in will send you to the looney bin. Keep in mind, I did mine with the dash still installed. I did learn that I'm more flexible than I thought I was...

vwnate1 · #63 05-14-2017, 10:39 AM

Yes ;

I was wondering how to ever get it back in .

I *think* this one was a replacement as it had a sticker with "R134a" on it, and in 1982 R12 was still the norm .

Delibes · #64 05-16-2017, 07:09 AM

Really enjoying this thread! The Benz Gods owe you one for breathing life into that poor neglected car...

nicholas · #65 05-21-2017, 11:49 PM

Can I ask where you got the head rebuild done ? I'm also in the Austin area and am looking at getting a rebuild on my 603 head as well.

vwnate1 · #66 05-22-2017, 07:11 PM

Me, I used Metric Motors in North Hollywood, Ca. ~ some Russian guys who don't do Mercedes but are never fazed by little things like the pivot pin for the belt tensioner being broken off in the head....

They also did the 1966 Chevy 292 i6 cylinder head I have including bronze valve guides and hardened valve seats, said " why not ? " when I asked if he'd tackle it .

They normally do Subaru WRX heads for the local kiddie ricer-racers, my Son has a WRX and they did good works for him so I figured no hard in asking .

Diseasel300 · #67 05-22-2017, 11:53 PM

I used a local individual with a machine shop to do the head on mine. He had done several 602 and 603 heads in the past and knew what to look for. Unfortunately he retired at the end of last year. I sent a PM to Nicholas about another possible machine shop in San Antonio, recommended to me by the same guy who did the work on mine.

In other news, the Diseasel got the mixture tuned a bit. Adjusted the ALDA CW about 2.5 turns to get the "coal rolling" under control. In addition to being irritating, the highway fuel economy has been dismal. Doing 75-80mph, I've only been averaging around 18mpg compared to 25mpg or so in city traffic. Since the tuning, I now have ~220 miles on about 1/3 tank of fuel. The same highway driving previously would have me below 1/2 tank. If it does ~25mpg or so on the highway I'll be completely happy.

A/C Update: Still blowing frosty cold. Much appreciated with the hot, humid weather we've been having.

Radio Update: Never going without a radio again. Completely spoiled.

Delivery Valve Update: "See the D/V as source of nailing" thread for full description. Polished the previously nailing D/V's with cerium oxide and oil and swapped them back in Cylinders 1 and 2 on the IP. So far, the nailing hasn't returned. Engine seems to be running fine with them in place.

Diseasel300 · #68 05-24-2017, 07:38 PM

So the fuel economy numbers are in. 24.1mpg for combination city/highway driving with the A/C cranking out the cold. I'm happy with that.

Installed a new bearing in the electric Aux fan in front of the radiator. Yay! No more banshee!

Perhaps the most interesting development is that the oil consumption issues have all but stopped since adjusting the ALDA. The engine hasn't dripped oil on the floor, and the oil level in the sump hasn't moved. I'm wondering if the engine was running so rich that I was getting fuel dilution issues in the oil. Would explain a great many things. For safety's sake, I see an oil change in my near future.

Diseasel300 · #69 06-09-2017, 10:02 PM

Incremental Diseasel updates:

Fuel consumption is still down, the car never smokes unless it's wide open at high RPM's. Oil consumption has dropped to the point I'm no longer worried about it. ~500 miles on this oil change and the level has barely dropped below the "MAX" line on the dipstick. The only change has been adjusting the ALDA. I strongly suspect I was dealing with severe fuel dilution issues.

Earlier this week I changed out the expansion valve in the A/C system. The original one kept hanging open. The result was that it would sometimes work and sometimes wouldn't unless you got the RPM up. Lots of gurgling and hissing under the dash as it hunted back and forth before finally sticking open. The new expansion valve has put an end to that behavior and I'm getting 42˚ air on a 96˚ day. I can live with that!

Helping the A/C system out is a new genuine MB monovalve cartridge. The original one had intact seals, but they were very hard compared to the new one. The movement of the plunger is also very rough compared to the new one. Not to mention that now the A/C blows like an icebox without having to fight the heater!

Just this evening I did another polishing job on a nailing delivery valve in Cylinder #5. Was successful in stopping the nailing. So far that's 3 for 3. This fall (when it cools off) I intend to do some IP work and I'll lap all 6 DV's at that time. The IP is leaking oil and needs new seals and I still need to tweak the RPM limit to let the engine rev to the proper limit.

Other than that, it's been business as usual. The SDL has been the "daily driver" for the last couple of weeks and been doing a fine job. Working A/C and a working radio sure make a difference in the creature comfort department.

vwnate1 · #70 06-09-2017, 10:31 PM

Glad to hear this! .

I really need to get back to doing AC works, I haven't since 1986 or so .

I may have missed the part about lapping (by hand I assume) the delivery valves ? .

I just bought five new ones and it helped a whole lot .

Diseasel300 · #71 06-20-2017, 11:29 AM

Been a while since I updated this thread...

The DV polishing can be found in reply 116 in this thread: Delivery valve internal leak as a cause of nailing? Yes? No? Maybe???

It's worth a read for the diesel guys, especially folks who have been chasing down nailing that won't stop and all the "usual suspects" have been checked and serviced.

In other Diseasel-related news, it goes on its first road trip this weekend. It's been running well lately, A/C and radio work, and the fuel economy has risen to normal levels. We'll see how it does in 100 degree temps driving over hills on the interstate at 80-85 for a couple hours each way. It needs a good run and I finally trust it enough to make the trip there and back. Hoping it doesn't let me down.

Diseasel300 · #72 06-25-2017, 10:23 PM

The Diseasel went on its very first long-haul road trip this weekend and boy what a doozy it was. I picked the hottest day in memory to take that poor car for a 2.5 hour drive at 80-85 out west on the Interstate.

The day I drove up it was 108˚F and HOT HOT HOT. I-10 going west has a lot of very long steep hills and west of Gillespie county has a speed limit of 80MPH. Quite the shake-down test for a tired old car.

The trip was completely unremarkable. Car made it without so much as a hiccup. A/C blew ice cold the whole way there and it had no problem keeping pace with traffic even when going up the steepest hills. On the trip going up, it used ~2 cups of oil, about 1/8" down on the dipstick in ~150 miles. This was down markedly from it's normal consumption on fast highway runs in the past. It would use up to a quart or more on a 100 mile trip if doing 75 or better.

Saturday we took it on another fast highway run for another 160 mile trip to go run some errands and do some thrifting. Car didn't use any oil on that trip despite doing the same speeds.

On the trip home, the ride was again uneventful. Car still didn't use any oil on the way home. I'm very happy with that result!

In addition to finally quelling its thirst for oil, my idle shake is also gone. MPG on the trip up was 22mpg, the trip home was 25.5mpg. I attribute some of that to the heat, but the rest to the engine finally working properly. I guess the old belief that these old diesels need to be ridden hard for a long period of time after sitting really is true. It certainly seemed to help this one! I suspect that the hot, hard, long run on the highway finally got the rings hot enough to cook the carbon and other crap out.

crazy4diesel · #73 07-01-2017, 04:20 PM

Quote:

Originally Posted by Diseasel300

After working on the interior, I turned my attention to the paintwork. I'd wanted a decent buffer, and this was my excuse to buy one.

Took several hours of buffing over several days, but I got the car buffed out and looking presentable. Hood still looks rough, but not much I can do about that until I break down and have the car repainted someday.

Nice car!

Curious if you addressed the clear coat, or just sanded and buffed what was there to work with. I'm not sure how long the buffing will hold up on the base color coat.

Diseasel300 · #74 07-01-2017, 10:17 PM

No, I haven't done anything with the failing clear coat on the hood. As the clear coat fails, it is slowly peeling off the hood and it looks much better than it did. I'm not intending to do anything to correct it since I'm intending on having the car repainted at some point in the future.

jake12tech · #75 07-02-2017, 06:02 PM

High temperature for a cruise at 80mph. All my diesels never run over 85C on the highway. Check your fan clutch.