Unwanted coal rolling

[Kerrvillian]

I have a new-to-me 1985 524TD that rolls some serious coal under full throttle acceleration. I'm sure that's not how they're intended to operate. Zero smoke under normal acceleration and 33mpg highway on the road trip home.

I'm familiar with Mercedes diesels with their ALDA. Do these have something similar that someone may have tampered with? I don't mind a little smoke with a good romp, but this is like a volcanic eruption!

[gadget73]

They do, there are a couple of adjustments on it. The full load fuel screw, the stop screw or "smoke screw", which is your no-boost fuel adjustment, under the cover you get the fuel pin and the spring that controls the application rate. I'll just link you to this which explains it better and has pictures. This is for a Rover but its the same pump and for a similar displacement engine.

https://www.google.com/url?sa=t&rct=j&q ... 92FmS_aubJ


its pasting in a stupid manner so if that doesn't work, google for "bosch VE tuning landyzone" and it should be the first link

what I ended up doing with mine was backing out the stop screw so that the pin was all the way up and rotating the fuel pin to add more fuel overall instead. I also tightened up the spring so it applies more slowly. Ends up with more fuel at full go and with minimal turbo lag, but it doesn't over-apply at low speed / low boost in order to keep the smoke under control. If I set the fuel pin to as lean as it can go it won't smoke at all but its painfully slow and the turbo just takes forever to do anything productive.


another thing that makes them smoke way too much is if the boost is low from leaks or the wastegate being improperly adjusted. The spring in the wastegate actuator gets weak and over time the boost ends up low, and those boots coupling the turbo to the crossover pipe and the intake plenum also petrify and leak. Stock boost spec I think is right around 10 psi. Would be worth hooking up a pressure gauge and going for a spin to verify it comes up to that. If its low and you can verify no leaks, adjust the tie rod on the wastegate actuator to tighten it up. Oil that before touching it though, just in case the parts are stuck.


I ended up using cheap ricer-riffic silicone hose couplers from ebay meant for cobbling up your own intake plumbing. BMW wanted quite a lot of money for 2 short bits of hose, I got both pieces on my car for less than half what they wanted for just one of the factory parts.

[Kerrvillian]

Link works for me. I'll look into it this afternoon. Car makes adequate power, it's just the insane amount of smoke at WOT that's a problem. The protection cap is definitely removed from the ALDA thing, so I'm going to start there. Turbo tube boots are in good shape and I know it's building boost. I'll have to quantify how much boost, but it's definitely boosting. I'll post back with what I find.

[Kerrvillian]

Checked into things on the car this afternoon and found a few things wrong. Boost sense line to the ALDA thing on the injection pump was rotted off. Got that replaced with new line and cleaned up the vacuum system, and deleted EGR while I was in there. The full load fuel adjustment still has the factory seal on it and has not been tampered with. The stop on the ALDA thing had been adjusted and I did adjust it with some success in reducing smoking, but what really made a difference was driving it while building boost. I drove it HARD this afternoon and the smoke production is far less. Accelerator has to be flat to the floor to roll coal anymore, and at this point I'm suspecting very worn injectors. I've got parts on the way to get into that and service the fuel system and have plans to remove the intake manifold and clean all the carbon and sludge out of it.

[gadget73]

Had my intake off when I had to send the pump out for an overhaul, there was a lot of oil sludge in there. I tossed it in the solvent tank at work overnight and a lot of it loosened up. I scrubbed out the intake ports and the oil separator while it was all apart too. The shop that did the injection pump tested the injectors and told me they were fine so I guess I got lucky there.

something I found with the intake gasket parts listing at realOEM, it will tell you that 6 are needed, but each gasket does 2 cylinders so you only need 3.

[Kerrvillian]

I noticed that about the intake gaskets. I've got a set on order and waiting on injector parts. The intake manifold is pretty disgusting inside and I have to believe it's a big part of what's going on. My old Mercedes 300SDL had the intake runners so clogged with soot/tar that it was breathing through holes about the size of my pinky finger. Deleting EGR and cleaning all that garbage out made a profound difference how it ran. I don't suspect problems with the IP on this car since it runs perfectly smooth and responsive. Starts right up every time you flick the key, so it seems healthy enough. Injectors nail loudly, especially when cold and it all screams worn nozzles to me. We'll see when the parts show up.

[gadget73]

Mine ran perfectly, then it started puking fuel out of the head seal. Apparently its a thing that sometimes happens with the VE pump and more modern diesel fuel. Found an exploded diagram and it scared me so I just paid to have it done. The seal kit is only like 60 bucks though. If I ever come across a spare pump for very little money I'm tempted to re-seal it just for the experience.


There is a cold start advance which makes it rattle more, and no guarantee the timing is right but verifying the injectors pop and spray properly on an old diesel is just a smart move anyway.

[Kerrvillian]

Lots of stuff going on, but been able to do the injectors on this car. As I suspected, they were terrible. The worst injectors I've ever tested and I've done hundreds of Mercedes injectors over the years. I'm surprised the car even ran and even more surprised how well it ran!

New set of Firad 314 nozzles went in and shimmed to pop within 50PSI of each other. Could not find the injector heat shields anywhere for sale, even European sources were coming back as NLA, so I did the old trick of annealing and pre-loading the existing shields to get them to re-crush.

BMW shows a lead time of 5-7 weeks for the intake gaskets, so cut my own using an old one as a template. Currently waiting for a temperature switch to show up, which should be here this weekend. The glow plug switch under #4 intake runner crumbled when touched and of course it's NLA. BMW shows it as a 78˚C switch, which I couldn't find an exact cross for, but I did find a 75˚ switch and an adapter fitting to use a generic one. Should be interesting to see how it runs with new injector nozzles. Pretty certain the ones in it were original to the car and had never been out based on the condition of everything I removed.

[gadget73]

The glow plug system doesn't use a switch, its a thermistor that changes resistance with temperature to control the glow plug on time. I think that lives up near #1. Should be the 2 terminal one. One terminal is for the glow plug unit, the other is used to turn on the electric fan on the BMW, on a Lincoln its the "your engine melted" idiot light.

I think the 78C switch is for the EGR. Per the Ford manuals, thats open below 78C and closed above.

[Kerrvillian]

There are 3 separate temperature switches/sensors on this head. One is a 2-terminal switch that closes at 105˚ to kick the aux fan on, one is a 2-terminal switch that closes at 78˚, and the last one is the temperature sender, supposedly to the gauge. The Aux fan switch is by #6, the one I broke that's the 78˚ switch is under #4, and the last one is up by #1. RealOEM doesn't show what their purposes are and the information I've read is vague, but when I looked up information on the part number, more than one thread came up on various forums about the purpose and supposedly it is to disable the glow system when the block is hot. Is it right? Who knows, but since the intake manifold has to come off to get to it, it's getting replaced while I have it off. What a PITA that thing is to get off! Definitely a real BMW.

[gadget73]

I didn't find the intake to be too bad on mine honestly, but someone had been in there before based on the missing wave washers. I got a bag of nuts and washers from McMaster and replaced all of it.

Odd question, were your intake nuts 12mm or 13mm head? All of mine were 12, which is apparently the JIS hex size for that size thread. The injection pump took a 13 which is DIN standard. I swapped it all to 12mm since it made it much easier to get a socket on the injection pump to set the timing.

seems like the arrangement of the switches and sensors is a little different on the Lincoln v BMW. The switch at #6 on mine is used for the climate control system to lock out the blower when the engine is cold. I want to say that one is closed under 40C or something. Mine is bad so its unplugged in order to let the fan work. The aux fan doesn't ever turn on with the Lincoln, I get an idiot light instead. I also get no temperature gauge. I've been meaning to modify the idiot light circuit to also throw a relay to kick the fan on when that light comes on. The fan only runs on low speed, and only for the AC in stock form.

for some reason I'm thinking mine has 2 switches up by #1.

either way the glow plug controller shows just an NTC thermistor, not an on/off switch wired in to it. It won't come on if the sensor is above a certain temp, and the time it runs varies based on temperature. The Ford manuals linked in the sticky at the top of this forum have those diagrams. No idea whats in the BMW books but the Ford scans are pretty good quality. The BMW scans aren't as readable.

[Kerrvillian]

Based on gut feeling and the fact that everything was intact and apparently factory on this engine, I don't think it's ever been into before. The injectors have certainly never been out and all of the annoying holders and brackets that BMW puts in after the fact to piss off the service tech are still present. Getting the coolant line brackets out of the way to get the intake manifold off were a huge pain. Access to the lower nuts on the manifold is terrible too, no wobble head is getting on there and access with a wrench is awful. Add in the fact that they ran the main engine wiring harness THROUGH the manifold runners and the only way to get it out is to disconnect everything.......yeah. Fun!

All of the nuts on mine were 13mm with a wave washer. There were some 10's for various other things, but all of the manifold nuts were 13's.

I finally got my ETM for this car yesterday and spent some time figuring out what the various sensors in the head are for. You were correct, that 78˚ switch that fell apart is for the EGR system only. Since EGR is deleted on this car, I've elected to simply delete that sensor and leave the remains of the base in the head. Goes to show what listening to the Internet does. I should have known from learning about Mercedes, but we all make mistakes.

There are 3 other sensors in this head. By #6 is the high speed fan switch. By #5 appears to be the coolant temp sensor which is integrated with the glow plug sensor, though I have not been able to confirm that definitively. The ETM shows aux fan current flowing through the switch and this sensor is an ECM style connector that isn't going to handle much amperage. #4 is the EGR temperature switch. The one up by #1 is the low speed fan switch I believe, though I haven't confirmed that definitely. It's possible I have the #1 and #5 switches reversed, but I'm pretty sure it's right. BMW doesn't help matters by calling them both "Engine coolant temp sensor" or "Temperature sensor, water" in the parts catalog.

It's very interesting to lay hands on the printed ETM for this car compared to the PDF that's available online. There are considerable differences that seem to match the car as it was produced, including pages with new prints glued over the original publications and components marked out with red ink. Money well spent.

Seeing on the lack of activity in this subforum, lack of activity on other forums, and the huge list of NLA parts, I'm getting the feeling that these cars are nearly extinct in the wild. It makes me want to save this one and keep it going even more.

[gadget73]

aux fan contact in that sensor should kick the relay on. Its not going to handle the load of the fan directly thats for sure.

They only imported around 1600 of those total so even 30 years ago it wasn't exactly a common ride in the US. Europe got a fair number of them though. At this point they're definitely a rare item.


maybe the bad access is why someone put 12mm nuts on mine. I don't specifically remember what I used to get it out, other than it not being a horrible ordeal. Also Ford vs BMW for some things, my harness doesn't run through the intake runners, it mostly lays down low near the glow plugs.

[Zeta]

Seeing on the lack of activity in this subforum, lack of activity on other forums, and the huge list of NLA parts, I'm getting the feeling that these cars are nearly extinct in the wild. It makes me want to save this one and keep it going even more.

I saw two other td's in Texas when I lived there. There was a delphin one in pretty decent shape that I was set on buying, but someone else snapped it up, and then I found Pendleton. The other one I kept seeing around San Marcos when I was doing my undergrad at Texas State. It was pretty clapped out and had been given a horrendously bad blue respray. Nonetheless, I happened to see it in a driveway with the owner working on it, so I pulled up in Pendleton and chatted with him a bit. He seemed to appreciate the novelty of the car, but didn't have the money to take care of it properly and was too content with settling for cheap, short-term solutions to problems. I hope that car has survived and found a more capable owner.

[Kerrvillian]

Car will still roll coal if you stomp it to the floor and lug it, but otherwise, it's a big improvement. No more sputtering at cold start or clouds of white smoke, significantly improved power delivery, and a much quieter idle. No more sounding like you're in a blacksmith shop from the nailing injectors.

My next challenge is figuring out what to do about the fuel filter. I ordered a new one that's supposed to fit the car, but the water sensor doesn't fit. Very annoying!

Today the car got new brakes so it doesn't feel like you're gonna die every time you attempt to stop and an oil change to drain the liquified coal out of the sump. Additional improvements include H4 headlights so it's possible to see where you're going. Handy feature in deer country.

I saw two other td's in Texas when I lived there. There was a delphin one in pretty decent shape that I was set on buying, but someone else snapped it up, and then I found Pendleton. The other one I kept seeing around San Marcos when I was doing my undergrad at Texas State. It was pretty clapped out and had been given a horrendously bad blue respray. Nonetheless, I happened to see it in a driveway with the owner working on it, so I pulled up in Pendleton and chatted with him a bit. He seemed to appreciate the novelty of the car, but didn't have the money to take care of it properly and was too content with settling for cheap, short-term solutions to problems. I hope that car has survived and found a more capable owner.

This car came from Houston. The paint is burnt and in need of a respray, but for now it's been knocked down with sandpaper and buffed so it's at least kinda presentable while I use it as a rolling project. It's Cosmos Blue (or at least it used to be). Attempted to charge the A/C today and hit a snag when I discovered that the compressor clutch gave up on life. It's always something.

[gadget73]

pretty sure the BMW uses the same fuel filter as the Lincoln. I've been using the Motorcraft filters that Rockauto has on clearance. Still 22 bucks a pop but they do fit. Inside the box its a Mann filter.

Oil filters might be an issue in the near future. Rockauto has 1 left. Wondering if I need to come up with a remote mount oil filter just so it gets me something common and available. Appears that the stock unit just bolts to the block, so if something doesn't already exist, it shouldn't be too big a deal to create one from a block of aluminum milled into the right shape with some fittings in the correct places.

[gadget73]

oh, something I found with mine this weekend that may be related to some of the smoke. The vac line on the altitude compensator was on the wrong connection. It should be on the outboard fitting, not in the center. In the center you get full vacuum on the bottom of the boost compensator, so it adds more fuel for a given boost level. There is a whole section in the manual for troubleshooting that but if you tee in a vac gauge to that connection, at sea level it should read around 10 inches of vacuum. Mine was at 25. Fixing that reduced the off-idle smoke considerably without affecting performance in any noticeable way.

[Kerrvillian]

Wrapping this all up, I've finally had success getting this car tuned properly. I've never touched the max fuel adjustment on the injection pump since it still has it's original seal on it, but I did get the smoke production under control with a combination of adjusting the position of the diaphragm in the boost compensator and adjusting the preload on the spring inside it. The procedures for adjustment were provided in the document way up in Reply #2.

Getting the injectors rebuilt was the first piece of the puzzle, and arguably the most important since the original nozzles were completely worn out. I did finally get a fuel filter that fits. The Champ/Luber-Finer that RockAuto sells is a reboxed Mann filter that fits perfectly. The Vaico filters sold as fitting these cars DO NOT fit the water sensor in the sump.

In the process of changing the fuel filter, I solved another issue that's been intermittently irritating. No matter what I did, I couldn't get the fuel filter to prime after changing it until I slammed the driver's door, then suddenly the fuel pump ran normally. I've had several instances of long cranks and weird low-power issues and finally traced it down to loose terminals on the fuel pump relay. With the rubber cover pulled back, the relay would just fall out of the plug. Re-tensioning the terminals has the pins gripped nice and tight and the fuel pump running with every key cycle, along with the engine instantly starting on the first compression hit. The previous owner replaced the fuel pump in the tank, probably because it wasn't running. I suspect it was probably fine and they were chasing the same issue with loose terminals on the relay.

I've also been having a weird flickering "Fuel Injection" light at random times, always when decelerating. Car runs normal and no weird symptoms, but you get that light. Other than decelerating, I can't pin any correlation to any other event happening. I installed a Holy Grail ATC fuse conversion in the car last weekend, but had no effect on the flickering "Fuel Injection" light at random times. Figuring nothing to lose, I yanked the ECU and recapped it. So far I haven't had another instance of the "Fuel Injection" light being on, so time will tell if that was the issue or not. I do know that ALL of the capacitors were either completely dead or way out of spec. This seems to be pretty common on German cars of this vintage, so a recap is a good idea even if it doesn't fix the problem you're after.

To summarize, the car runs like a stabbed rat. Smooth, powerful, and quiet and surprisingly quick for what it is. Now that it's tuned up and has new injector nozzles, the smoke production is essentially eliminated. It produces the very slightest haze if you have your foot welded to the floor and holding the kickdown switch, but any other time it's completely smoke-free.

When I got this car, I got it sort of tongue-in-cheek thinking it was kind of ridiculous and bound to be the slowest thing on the road with a wimpy 114HP diesel in it, but it's really grown on me to the point I think it may be my favorite car. (Just don't tell the Mercedes that). Had I been old enough and had the money in 1985, I could picture myself actually buying one. To me it makes more sense than the ETA cars and it's a shame they didn't sell better than they did.

[gadget73]

yeah they don't suck as much as the power numbers imply. Glad you got it sorted out instead of using it for a parts donor or an engine swap candidate like many seem to end up.

By the time these came around I think the US passenger car diesel market had been poisoned so much by GM's garbage diesels that nobody wanted any parts of them, even though they had nothing in common with the Olds motors.

[Kerrvillian]

Yeah, GM really piddled in the pool with their garbage. You can see the same decline in sales with the MB diesels. Finding W123 and early W126 cars with the OM617's is like tripping over sticker burrs, but finding an 86/87 with the far superior OM603 is surprisingly hard. By the time they came out, the diesel market was dead. I really like this car and I intend to keep it around and going as long as possible. Current challenge is getting the A/C working. It's WAY too hot to keep sweating it out in that car.

[gadget73]

I get picked on for having working AC in my cars because its a "waste of money" but when its time to go somewhere I always get volunteered to drive because my AC works. I also have tinnitus and driving with the windows open just makes my ears scream even worse than normal. Driving while sweating and listening to my own head ring is not exactly my idea of a good time.

[Kerrvillian]

Working A/C is a requirement in any of my cars. I'll fix the A/C before I'll fix the suspension, body, or radio. Few things are more miserable than driving in 95+ heat with the windows down sweating your ass off.

Happy to say I got the A/C going in this car yesterday evening. The compressor clutch was bathed in 20+ years of caked on grease and schmoo from the air filter box dripping on it (great design, BMW!). With nothing to lose, I emptied 3 cans of brakkleen on the clutch to flush it out and lo-and-behold, it works fine! Topped off the charge and I had nice cold air while it was 97+ with heat index close to 110 yesterday evening.

That led me to my next unpleasant discovery. Some SERIOUS heat coming up from under the dash, like the heater was on high through the leg vents. The heat was not on and the change in air flow was dependent on vehicle speed. I checked the heater valve cartridge and it was fine with no tears. Found the issue on this forum (of course). Easy fix. Missing body plug and operator error. The body plug was easy. Pressed it back in and added tinfoil tape to keep it secured. The operation of the HVAC controls were more sinister, I've only messed with the A/C on 86 and later E28's with the automatic recirculation flap and didn't realize if you leave the middle vent lever open, it lets in outside air on the pre-86 cars. Annoying!

Link to the post that helped me out in case anyone ever runs across this thread trying to fix the same issue.
viewtopic.php?p=569942#p569942

[Zeta]

The operation of the HVAC controls were more sinister, I've only messed with the A/C on 86 and later E28's with the automatic recirculation flap and didn't realize if you leave the middle vent lever open, it lets in outside air on the pre-86 cars. Annoying!

Good to know! I was not aware that any of the cars had an automatic recirc flap, so I always close the middle slider on my 88 when using the AC. I guess that's not necessary.

[Kerrvillian]

The operation of the HVAC controls were more sinister, I've only messed with the A/C on 86 and later E28's with the automatic recirculation flap and didn't realize if you leave the middle vent lever open, it lets in outside air on the pre-86 cars. Annoying!

Good to know! I was not aware that any of the cars had an automatic recirc flap, so I always close the middle slider on my 88 when using the AC. I guess that's not necessary.

The question is: Do you trust it? It's a BMW, I wouldn't. Stay in the habit of using the sliders!

[Zeta]

I’ll compare the vent temperature with the slider open and closed and see if it works. Now I’m interested.