Mercedes OM606 turbo Diesel 80 series Land Cruiser

[LandCruisinMy93]

Next we need to mark the Gauge Cluster harness ends to match our circuits. Its easier than reading a wiring diagram. Transfer your marks from your cluster to the appropriate ends.

Above is the opposite end of the sacrificial wiring end I marked on the tiny gray cluster plug with an "S". This plug like many others that connect at the cluster is behind the glovebox. If you didn't gut your wiring harness out like I did you just have to find the matching color code wire in that cluster of plugs. The you can use a voltmeter set to Ohms, or if you have one like mine with tone to make sure it is the same wire with a quick continuity test. Luckily I kept the bag of wiring gut and was able to retrieve the wiring end for this plug and use it to splice into my glow plug lamp signal wire. It sure makes things nicer and cleaner to be able to run that signal through pre-existing harness wires.

P.S. Don't judge the bundle of spade connectors, I don't do any permanent wiring in crimp style connectors. Those go to the recently Re-installed Dakota Digital Tach Converter. When I revise my engine bay wiring harness I will put a weather-pak plug on.

 

[LandCruisinMy93]

De-pin & Re-pin gauge cluster plugs. A good set of Micro/ Precision flat blade screwdrivers is highly recommended. These Stanley precision screwdrivers were cheap at Wal-mart and are awesome for this work.

Step 1: Locate the big white lock on the plug, I chose to show the blue plug for the contrast but the sliding lock is pretty much the same on all the gauge cluster plugs.

Step 2: The Sliding lock will slide both down and up. It needs to go Up/Out the top. To accomplish this, insert the tip of a SMALL flat blade just between the lock and the plug body and pry the plug body away slightly. Then push the block free of the body and remove,

Step 3: Remove the inner pin lock. To remove the inner pin lock locate the tabs on the sides of the plug. Using a small flat blade screwdriver push the pins in and upward gently to free them. Note, you don't need to push the pin too hard or to far up or in, pushing the pin too high on one side results in that pin reseating as soon as you free the other side. Once both sides are freed, you can fish the lock out from the top of the plug using the screwdriver.

Step 4: Removing the pin. The first picture in the next post is a little blurry but you may still be able to make out the little tabs inside the plug. Find an unused spot in the plug and look inside to see the little retaining tab. You will notice a small protrusion from the very end of the tab. You will want to take the thinnest flat blade screwdriver you have; and insert it down the front of the plug between the Pin and the little protruding tab. Lift the tab slightly and gently and give the Pin you're trying to remove a slight tug until it slides out. If you pull before you pop the little tab up, you're likely going to ruin the tab and struggle and get frustrated.

 

[LandCruisinMy93]

de-pin & re-pin continued

Tagging your wires as the are removed cuts down on confusion when you swap wires around.

And the pin is inserted into its new plug and the plug is reassembled in the reverse order.

REVERSE ORDER: Insert pin until it locks, give a slight tug to insure it is seated. Insert the wire lock, the serrated one, insure the side tabs lock in place. Insert the main lock until it clicks under the edge of the plug body.

 

[LandCruisinMy93]

Gauge Cluster disassembly

Step 1: Using a small flat blade screwdriver locate the tab on each end of the Gauge cluster. Gently pry them up to free them.

Step 2: Flip Cluster on the top edge so that you're looking at the bottom edge. Using a small flat blade screwdriver gently push down and toward the cluster lens on the 4 black tabs indicated by red arrows. Be careful and make sure you're not forcing anything. If it feels like you're fighting it, check the end tabs again.

Step 3: Flip the cluster onto its bottom edge to release the top 3 tabs in the same manner. The cluster lense and internal bezel should slide off now exposing the gauge faces and indicator lenses.

Step 4: Swap the indicator lenses by simply lifting the appropriate lens and replacing it with the other.

Step 5: Replace the cluster lens and bezel assembly insuring it is fully secured at each tab. At this point you will need to re-install bulbs for the appropriate indicator lamps and plug your cluster back into place. Test that the indicators that where swapped around or added work properly.

Step 6: Assuming that all is well and that your indicator lamps all work as they should it's time to Reassemble the dash. Reassemble in the reverse order by following this post backwards until you've reached the end. Use those pictures of the switches to get the switches back in their appropriate places.

 

[LandCruisinMy93]

A NOTE ON GLOW PLUG LAMP SIGNALS

Our Gauge clusters expect a Negative battery signal for most of their indicator lamps. That being said, some glow plug relays send a Positive signal to light the lamp like the mercedes glow plug relay. There are ways around it if this is an issue for you also. You can either use your glow plug lamp signal wire to operate the switch of a relay that sends ground current to the cluster. Or you can be lazy like me and do some modifying to your circuit board with a soldering iron and some thin rosin core electronics solder.... I use a lot of this tuff for all of my wiring so I have it on hand.

The pictures are pretty self explanitory...I hope.

You need to separate the glow plug lamp positive input from the neighboring lamps by cutting a narrow strip out of the circuit where its marked. Then use a razor to gently scrap away the plastic and expose the copper filament underneath. With a hot soldering iron you'll want to dab some rosin core on the tip and apply it to the copper making sure not to over heat the circuit board plastic...You just have to get the solder to stick.

Then You trace this circuit I labeled for you, it is a ground circuit. Find a spot to bridge too and again, gently scrap the plastic off with a razor. Again, add a dab of solder as before.

Lastly you'll want to take some thin gauge wire and strip about 1/8 inch of insulation off one end. Apply solder to the stripped end until the wire wicks it up. Then press the soldered end of the wire into one solder point of your bridge with the soldering iron to fuse the wire to the circuit board. DO NOT OVER HEAT IT. If you can't get the wire to lay down nicely, poke it down with the flat blade screwdriver and then heat it and hold it down while it cools.

Route the wire as you desire and clip off excess. Strip the wire as before and repeat the soldering process for that end of the bridge. Viola! If you haven't burned holes in everything You've done it, make sure to test the circuit for function before fully reassembling the dash.

 

[LandCruisinMy93]

Update time boys and girls. I am waiting on vise jaws to assemble my shiney AN hoses, meanwhile I made a turbo drain hose by canabalizing some old stuff for pushlock fittings. I also took the spare valve cover in to be powder coated an anodized red to match the fittings. I have installed the Hy35 hybrid turbo with the new block drain and turbo drain fittngs. I also installed the new exhaust manifold. I'm utilizing the old oil supply line for the the time being. I have to make new intercooler piping for the turbo side now. I'm waiting on a silicone hose adapter, apparently the turbo compressor outlet is 2.75" not 2.5".
I installed the filter housing that had the tuna can removed, I also made a simple intake tube which consists of a 3.5" silicone 90 at the filter housing pointing down toward the turbo and then a 4.5" to 3.5" reducer silicone 90 the two are connected with a sbort 3.5" diameter aluminum tube.
I spent some time installing a new alarm. It appears part of my intermittent no-start issue was due to a failing immobilizer relay in my alarm. I installed the Viper 5906v which utilises some of the same wiring as the old clifford; but there was a fair amount of re-wiring, programming and trouble shooting to be done. I still have to figure out the shutoff solenoid situation. The remote start will try to start the engine but for some reason the shutoff solenoid stays open so the engine can' get fuel. Its on the list.
I spent some time today cutting up mandrel bends and making a down pipe for the new turbo. I was able to get it tacked up and ready for welding. I am not looking forward to that part. My TIG welding skills are sub par and not having 4 arms to do exhaust stuff sucks...especially when you don't have a good welding table or a foot pedal or flex head torch. The 17 style torch that came with my esab is serviceable, but really cumbersome.
Lastly, I made a blanking plate for the fuel heater hole that will hold new accelerator cables. I also added a pivot ball onto the throttle lever on the injection pump directly below the other...the lever I cut off when I first got the pump and had to weld back on...hindsight is 20/20. This way I can have a cruise control cable too. I will install that when I install the new injection pump. I have some other stuff in the works but don't want to report anything that isn't successfully completed.

 

[ccslider]

Great work. I love how this shows you don't need some fancy decked out shop. A floor and a cooler with a little motivation is all you need.

 

[LandCruisinMy93]

Great work. I love how this shows you don't need some fancy decked out shop. A floor and a cooler with a little motivation is all you need.

I appreciate the kind words. A very messy floor for sure. Along with this work and all kinds of other small fabrication stuff I'm also going through a cleanout of all scrap metal and the garage has become quite a disaster.

 

[LandCruisinMy93]

Well, it's been just shy of a week since I started my exhaust build and now have a complete 3" stainless steel exhaust. I routed it as closely as I could to the original design. It comes out where the original did and is held together by 3 Marman joints, the Marman joints are 409 stainless so they will likely rust, but the rest is 304. Here are a few pictures of individual pieces. I didn' t get one of the finished resonator, but its pretty spot on to the original muffler "S" bend where it goes over the frame cross member. I don' think I will be getting any pictures of the full thing assembled outside the truck; but who knows. It's not difficult to take out... I'm just a bit battered and feeling lazy. And judge all you want on my crappy cooked tig welds, I'm still learning and burning new holes as I go .

 

[LandCruisinMy93]

I finally got around to making a new charge pipe for the new turbo. Much nicer than the old thin aluminum one I MIG welded together. I made the new one from 2.5" mandrel bent stainless tubing. I bought a regulator T-fitting so I could run my second regulator off of my one argon tank for back purging. I couldn't believe the difference back purging made on the charge pipe. There were no burn throughs, no sugaring and the welds came out really nice. Eventually when I make a new intake manifold I will make a new intercooler pipe for the manifold side too. I also got all the gaskets for my Marman joints so I will install those tomorrow and do some other things hopefully. I will get a picture of the new charge pipe tomorrow, I'm going to be adding a section to make it a single piece. Originally I wanted to leave a gap for a hump hose, but there is really no great place to put one.

 

[Bryan Plunkett]

How does the exhaust sound? Do you have any resonance issues with it? is it mounted on rubber hangers or hard mounted? I ask as I had a pretty bad drone resonance until I added a flowmaster super 50 muffler (i'll add a video comparison to my thread sometime today). It still has a few rpm points where it's basically a vibrating the cab that I need to address with more mounts, more weight or squishier mounts...tbd

 

[LandCruisinMy93]

How does the exhaust sound? Do you have any resonance issues with it? is it mounted on rubber hangers or hard mounted? I ask as I had a pretty bad drone resonance until I added a flowmaster super 50 muffler (i'll add a video comparison to my thread sometime today). It still has a few rpm points where it's basically a vibrating the cab that I need to address with more mounts, more weight or squishier mounts...tbd

Exhaust sounds decent, but I haven't really ran it much since I've been working on so many other things. As far as resonance, the muffler was replaced with a 4" inlet/outlet FTE Diesel resonator that was longer than the original muffler until I cut it down and added reducers to a 3". I honestly hear more engine clatter than exhaust. I used two of the three toyota rubber isolators and built hangers onto the exhaust to match the old ones for the most part. The third isolator was too flimsy to hold the over the frame bend up once the resonator weight was on it, so I made a stainless steel box with 4 bolts to mimic the rubber isolator.

 

[LandCruisinMy93]

Well, at the risk of jinxing myself. Preliminary tests are looking good for the cooling system mods that I've been working on; and the throttle cable setup looks like it's working also. I will need to get some miles on it before I can say it works properly.

Cooling system mods: Mercedes in their infinite German wisdom engineered the coolant return from the heater core to look like a skewed question mark shaped tube. It comes out of the back of the water pump housing...is an O-ring fit and has a bracket to keep it from popping out. The inlet to said tube point at the passenger headlight...yep it points forward. So I had something like 6 feet or so of heater hose coming out of the heater core and going to the engine...in there was the brass T-fitting so I could hook another 3 or so feet of 1/2 hose into it for the rear heater. Well, I took a page from.the 1FZ book and made a stainless hard line that bolts to the cylinder head and carries the coolant to the water pump. The initial design was similar to the cruiser, but I quickly realized I needed a second port on the hard line for the 1/2 hose...so I added a second 5/8 port...because I didn' have any thin wall stainless in the 1/2" flavor.

Anyway, I took the spare water pump housing and welded the port for the inlet tube closed. Then I drilled and tapped the unused cast port in the water pump housing just forward of the thermostat housing. I drilled and tapped it for a 3/8 NPT fitting. I used a -10AN to 3/8 NPT swivel 90 degree fitting to thread into that and a -10AN straight pushloc fitting to connect a length of heater bose to the tube. It all sounds a little complicated but it' quite simple and seems to be working.

While the cooling system was open I removed the radiator and made a mount for the oil cooler that bolts where the "Paperclip" power steering cooler bolts. It puts the cooler just behind the radiator (engine side) and in beneath. I went to prime the cooler before installing only to find it had a broken solder joint and was leaking. So I have a replacement on order.

I removed the fuel heater and swapped in a homemade throttle cable holder. I then cut down a brand new toyota throttle cable and silver soldered on an M6x1.00 stainless steel screw I had drilled out. This allows the little pivot socket mercedes uses for their linkage to be connected.

I swapped the new powder coated valve cover on also. While the new injection pump was being swapped in I decided there was no better time, especially since the throttle assembly moved to under the intake and I could now use the mercedes vanity cover. After the cover was on and all the injection lines etc... were done I put the PCV back on and cut down the hard plastic tube about 3/4 inch, added a second rubber straight coupler and pushed a 90 degree -8AN bulkhead fitting in. Then connected a 45 degree fitting on the other side which will be made into a braided stainless PCV hose that attaches to the air cleaner housing.

Lastly I just did a few small adjustments to some things I've been meaning to do, like shortening the intake side intercooler tube in a couple spots to make a better fit and get rid of excess tube. I re-beaded the ends with a homemade beading tool. Doesn't quite have enough force to bead the stainless though. Then the Intake adapter had a couple inches taken off also.

That's about it for now. I have to return my JEGS brand -12AN fittings, wrench and vice jaws because the fittings rounded trying to make the drain line for the turbo...they're about 3/16 from flushing out and they required so much force to get to that point that the wrench expanded and rolled around the collars and the aluminum vice jaws dented the collets. Jegs says that' a first, but measuring their fittings shows that the collars and collets are metric and the swivel part is standard...just like the Chinese ones on ebay that sell for 1/3 the price. Anyway, as soon as I get some AN hoses made I will put some pics of that up too... onto pictures.

 

[LandCruisinMy93]

A few more pictures.

Just in case you were wondering, I did in fact bead the ends of the coolant hard line where hoses attach... I purchased Earls EZ Beader tools...which are apparently good for about 3 beads before the inside of the beader is all marred up. I'm definitely returning that one.

 

[Bryan Plunkett]

Nice man, it's looking really clean now!

 

[LandCruisinMy93]

Nice man, it's looking really clean now!

Thank you, coming from you that means a good deal. There is obviously a bunch of small stuff left to do, but it seems like it's coming together. My main hurdle at the moment is AC. Figuring out what to do about that. As you know, mercedes used one big ole funky fitting on the low side of the compressor and I just can't find a good way to utilize either of the hoses or the hose ends I have for it. Not to mention it's metric lines and most aftermarket is standard.

 

[LandCruisinMy93]

@Bryan Plunkett brought up a turbo oil feed question in a side bar conversation. The oil feed line I'm running is coming from the back the the oil filter housing. It' not because it' a better feed source or anything. It' because I planned on sticking with compounds and didn't have a cap for the -4 line and because it's more difficult to get to and I was trying to save some future headaches. The cap on the side of the block by the turbo is where my new -6AN feed line will go once I make it and the -4AN will get removed.

 

[LandCruisinMy93]

Well, it drives! I've put 26 miles on the new pump. It takes off well 70% of the time, the other 30% of the time it takes off a little slow but nothing like before...it doesn't try to die or anything. It does roll coal A LOT and idles around 1100-1200rpm. I sent out a message to the pump builder asking if I can turn the idle down and how to properly cut fuel back.
I'm sure everyone on the road will appreciate my efforts to not roll coal.

The exhaust sounds great...I think. It definitely has a nice throaty tone and some anger when you get on it, but it's pretty quiet the rest of the time. There isn't any drone that I've noticed.

The old haggered stock om603 pump felt like It provided more power than the all wheel drive 1fzfe land cruiser did, even with it's tiny turbo. The take-offs weren't as good by any means, but the power acceleration were better once it was rolling. This new pump is a HUGE difference. The throttle setup is too. I feel like it needs another spring or a heavier spring on the injection pump because it doesn't take much to give it too much pedal. It's crazy how softly I have to push the pedal, I used to have to really smash it. If I do that now I'm 2 blocks down the road and scared before I know what' happened lol.

There is still a lot of testing to do and nuts and bolts to check to make sure everything stays bolted down, but overall I'm excited to have it driveable again. I have to add an oil cooler and hopefully find my oil leak (minor) which I'm thinking it actually the oil cooler fittings I tig welded up in the beginning. I think there is a pinhole in one or both fittings. I guess I will know when I swap them out...i may just be swapping leaky fittings for more leaky fittings, who knows.

There are dozens of little things left to do that will be done over time and as time permits, but hopefully the cruiser remains roadworthy for many years to come. I still have a growl in the transmission but it seems like its getting better at the moment. I'm going to drain the fluid and check it and swap in some good quality fluid and see if that helps.

EDIT: Since I didn't want to start a new post for more work done today. I got the idle adjusted down and turned fuel down some. I need to take it for a test drive still and adjust until it's where I want it to be. I made the new turbo oil feed line, once again JEGS fittings were metric and the wrench didn't even fit over these ones. It appears JEGS brand fittings are just the chinese fittings on ebay with their logo. Design, size, anodize color tone etc...are that same as the ones I purchased for the PCV drain. The Jegs wrenches may work on name brand fittings, but they sure as heck don't work for their own stuff. I ended up using a crescent wrench and a bunch of rags made of old t-shirts to tighten the fittings... it did a lot better job than the special wrenches but took forever and still had some maring here and there, nothing too bad.

 

[LandCruisinMy93]

This last week I was able to install the oil cooler and AN cooler hoses as well as the new turbo oil feed line. I did some more test driving inspected all of the mounting hardware and tightened everything up. I'm still chasing some minor oil leaks which is kind of to be expected with diesel engines, I ,however, want as clean of an engine and transmission as possible.

I also made some washer bottle relocation brackets to allow installation of the second battery tray. Instead of cutting and splicing in some wire I depinned the one wire in the one plug that was holding the oil pressure wiring harness and washer bottle harness to the charge wiring. I then moved the oil pressure harness and washer motor harness back behind the cruise control unit and it worked out perfect. I then took the wiring out from the passenger side to the fuse box and re did the charge indicator wire which I had loomed separately.

After everything was reassembled I installed the second battery tray. All that is left to do for that is buy a second battery, the wiring and components and figure out what all is going the be run off of the second battery.

I need to get ahold of a timing light adapter to set the timing before I cut the fuel back any farther. There is no sense in trying to tune the fuel if im not positive the timing is correct. In the meantime while I search for local shops that have the adapter, I will work on th making a bracket for, mounting, wiring, plumbing and my ARB twin air compressor.

Well, that's it for updates as of now. Thanks for tuning in and taking the time to read my posts.

 

[anothernord]

Sweet write-up on the cluster lense! Thanks for doing that. I'll be following suit ...someday.

Really like the look of the stock airbox in there. If there weren't a big mercedes logo on the engine, you'd think it was all stock.