Cheers from Utah
 

Hey all, I just picked up a 1990 300D 2.5. I've had a long relationship with diesel vehicles, namely VW, but I've always longed for a nice Merc. The attention to detail and mechanical complexity of the Merc is a thing of beauty. It's just staggering to see the differences in something as simple as a fuel filter flange. All the banjo fittings, to the bleeding screws, the mounting flange, even something as simple and trivial as the bolts holding it to the engine. Just a gorgeous design and incredible engineering prowess. Next time you're under the hood, have a long look at that fuel filter flange... what a beauty. The machined surfaces, the quality of metal used in the casting. So.... German. Call me weird, but you just don't see that much anymore. There's nothing finer than a 3 point star.

That said, it's good to be here. Here's a few photos of my recent acquisition, it's pristine. I bought it from the original owner who was a doctor in Vancouver. It started it's life in St. Louis at Boulevard Motors (Interesting Article) I have every record in a folder (about 3 inches thick). There was even a notepad in the glove box that recorded every refueling since 1990, miles, dates, location and even fuel price. The original window sticker, all manuals and supplemental booklets. This thing even has the original MB windshield in it. I'm almost scared to drive it anywhere.

It does have boost issues (I ordered everything I need to switch to the pressure type WG actuator), there are vibration issues which presumably are the mounts. Other than that, it's been well taken care of. I plan to leave it mostly stock, except for perhaps the wheels. What a lovely car! I can't wait to work the boost bugs out, pulling hills are a bit ridiculous.

Being an early 124.128, check the records for timing chain and cam sprocket service.

Sixto
87 300D

Hey Sixto, thanks -- No mention of chain or sprocket. It's got 130k on it now, should I worry? I was planning on doing this in the spring, but I can bump it up. At the very least I was going to pull the valve cover and have a look at things. The CCV was leaking and stained some of the metal yellow, so I was going to hot tank intake manifold and valve cover.

Puling the valve cover is all you have to do to eyeball chain elongation - http://www.w124performance.com/docs/mb/OM60X/OM60x_Timing_Chain_TSB.pdf

CCV? Yellow stains on the engine are usually left over cosmoline, a protective coating applied prior to shipment from the factory.

Sixto
87 300D

Holy crap, I just ran into the VP thread here. Yep, I've got the old VP design. The new pump, timing device, cam sprocket and everything else I need to do the chain are ordered. Looks like the car is going to be parked for the rest of the week, too scared to drive it. :)

Looks like a very nice clean car....get a dash dolly to protect the dash and stay away from armor all.....

The side cladding can hide nastiness in rust belt cars. Pull the jack hole covers to see if the jack holes need attention. Check that rubber lifting pucks are present close to each jack point so shop techs don't deform the body where a lifting puck should be. I don't know if a '90 has early rectangular pucks or late round pucks.

Sixto
87 300D

I called my favorite shop to do the pump and check chain stretch since it's -5 degrees here. They tried to pull a fast one and mark the pump up to $500. Idiots. $325 and 45 minutes later, I had the new pump on. Cam plate was pristine and the old vacuum pump appeared to be in great shape. Nonetheless, I'm happy it has the updated pump on there.

My wastegate arrived and I already modified it. I'll be installing that and getting the EDS rats nest removed this weekend. While I'm at it, oil change with Shell 5-40, drain and refill of the autotragic with Mobil 1 ATF. Depending on how busy the machine shop is, I am going to have them bake and bead blast the intake manifold and valve cover to get that cosmoline crap off.

Also, is it taboo to plug other parts dealers here? I've got a great source for German filters and consumables for these cars, often cheaper than the Fram crap at Autozone... that is if it won't get me banned.

It won't get you banned but identifying info will be obscured. This site exists courtesy of a parts dealer, after all.

The cleaning effort on the manifold will be better spent on the inside than the outside.

Sixto
87 300D

Oh yes, I'm definitely doing this to clean the crap out of the manifold. TDI engines have the same problem and can actually constrict the main passage way down to the size of a nickel. Baking the manifold will result in a brand new appearance internally and externally.

Sixto, do the ports in the head get clogged off with crap too? I've found that very difficult to remove on the TDI.

Nice find....exact some color combo as my 91. Welcome to the forum.

If oil changes have been faithfully done (which it sounds like they have been), it is extremely unlikely that you need to address the timing chain with only 130k on the clock. VP is probably fine too, but I understand the peace of mind issue.

You've probably already done it, but make sure to replace the fuel filters as your first step to addressing a boost issue. Your goal in all this is 0-60 in 12.8 seconds (or reasonably close to it).

I don't recall anyone cleaning the manifold runners and enjoying increased power or mpg so it seems mostly for peace of mind. MB runners must be more generous than VW runners. You can clean the ports with the valves closed and extract whatever detritus is generated. It's a tedious effort compared with chemicals, pressure and heat used the manifold.

Sixto
87 300D

I see an '80s Ford truck in the second picture. What engine is it? How do you like it?

Haha! Keen eye, my friend. I've always like that body style of Ford Truck, but that particular one I don't really like. It's my dad's truck and he's attached to it so I'm storing it for him since I've got some extra land in the back yard. It's an 85' and has the 460 with a 4 barrel. Get's 11mpg on a good day. 2x4 unfortunately and gets stuck nearly anywhere in the snow or mud. I just recently got rid of my 86' F250. It had the 6.9L diesel with the ATS turbo kit. Best truck I've ever owned. Odometer had rolled over several times, I figure it had about 300k on it. That thing was a bomber in the snow and mud, great trucks if you can find one made of less rust than steel.

Sixto, check out this picture:

http://www.myturbodiesel.com/images/a4/TB_head_rem/clogged-intake-tdi.jpg

That's an intake manifold off of a 99-03 VW TDI. On the left, the intake manifold, the right is the EGR valve. That passage way is about the size of a US nickel. Interestingly enough, the engine still runs fine albeit with about 30% less power and mpg. Unfortunately, because the EGR is monitored by the ECU and the car is OBDII, you can't just disable the EGR. Some chip tuners have found a way to disable it in the ECU, so you can get rid of the EGR and it doesn't pop a code.

Well, the new wastegate is on. Getting that clip on the actuator rod was tedious! :madani: Hopefully never again! I also had to bypass the overboost protection to get the ALDA to behave properly. It pulls well now and the transmission behaves properly. I just need to figure out why the overboost system isn't working.

There appears to be two vacuum lines running down near the battery tray from the airbox area. I studied vacuum diagrams for this engine and it appears the reservoir is down there. One line had what looked like a fuel filter and it had the MB star on it, so it must be factory. I used one of the left over U shaped vacuum elbows to connect them together to eliminate a potential vacuum leak, but I wonder why there's two? The diagrams only showed on line running down to the reservoir from the air box area. I'd really like to simplify the rest of the vacuum system. Can the blue UFO be deleted if the trans modulator is adjusted accordingly?

Maybe I'm misunderstanding your question, but the whole passenger side of the vacuum system should now be disconnected and blocked off. So now, going off the pump, you should have a three way connector (two leads going to stuff on driver side) replacing the the four way. Is that how yours is now configured?

If there is a reservoir, it'll be fed, as such, from a line tee'ing off the main vacuum supply to the BFS a couple of inches from the BFS. It'll be a black plastic line about twice the diameter of the typical vacuum line. Why the reservoir is clear on the passenger side fender when the BFS is on the driver side fender is beyond me.

You can remove the BFS but shifts will be firmer until transmission fluid gets to operating temperature. You'll notice it less with synthetic ATF. You need only one green damper between the VCV and transmission modulator if/when you remove the BFS.

Sixto
87 300D

Well, you can tell idiots have worked on this car in the past. I was browsing through the records and found a rather recent record where a "transmission shop" added stop slip to the transmission... (EEK!:eek:). I immediately ordered Mobil 1 ATF and planned to drain that crap out. Upon doing so, flares between shifts were terrible! :( I checked the vacuum rats nest, all checks out with vacuum supply and the modulator holds vacuum. I adjusted the modulator 3.5 turns clockwise to get the shifts to firm up, now it shifts perfectly... PHEW! It really makes one wonder what else has been done to this car by idiots.

I do have a few questions for the forum... what is everyone's favorite diff oil? Should I use a multi weight synthetic or go for straight 90w? Also, I was looking at the flex discs and they've seen better days. Is there a retrofit to get rid of the flex disks all together? Like some kind of metal disc replacement, and what would the consequences be? I don't like having that as a failure point.

I love this car! I'm not sure I can ever go back to VW now... so much thought was put in to the car being easily serviceable. Fantastic engineering.

The key feature of flex disks is flex. A coupling that doesn't flex will put undue stress on the transmission and differential. Good quality flex disks will easily last 100K miles. That's 4-5 years for a heavily used car, twice or more that if there are other cars in the fleet. It's a small investment for almost no chance of failure.

Sixto
87 300D