Radiator conversion for 1980 240D
 

So, I bought the wrong radiator for my 240D and I'm curious about what it will take to just convert to the radiator I now have rather than deal with the hassle of returning it. What I bought by mistake was the radiator for the 1982-1985 turbos in the W123 and 126 chassis. I understand that I need to add the overflow tank because that's where the filler cap is, but I'm not sure I know where to put it. It seems like it would have to be the highest point in the system, and I'm not sure how to do the initial fill after the new radiator is installed. Also, can I get away with continuing to use the regular green coolant or is there a compelling reason why I should spend the $50/gallon for the special MB coolant?

Turbo to NA radiator swap
 

The mounting position for the expansion tank should be on the passenger side about midpoint on the fender. I don't know what's there on a 240, but there are brackets for mounting it in a 300. The mounts for the turbo radiator on the passenger should be the same, but it's about a 6" wider radiator. And the oil cooler mount may be different, it seems I've seen some different types of oil coolers in this chassis.

I have a nice expansion tank for sale. PM me.

It's totally doable. Slightly larger in size but should mount the same and fit. You'll need the tank and the hoses to connect the tank and you'll have to Fabricate a bracket to mount the tank. zyrex g-05 coolant is the stuff.

Well if your 80 240 is like ours, you have the small unpainted aluminum Oil Cooler. Both of the hoses connect to the bottom. I don`t know how the Cooler would attach to the Turbo Radiator. it would be best to source a Turbo Oil Cooler from PNP. they are around $20.

The Turbo Cooler is attached to the Radiator top and bottom with a bracket and one bolt. ( one bracket top and one on the bottom, each with their bolt)

So your 240 hoses would not work, unless you can figure out how to attach the 240`s Cooler.

Start looking at other peoples 300D`s at how the expansion tank is mounted. you might be able to remove some brackets from a parts car, or even make some.

You will need the hose from the Expansion tank to the bottom of the Radiator.

If you decide to use a Turbo cooler, then there is the hose problem, buy new, source some used ones. or do as mach4 did with his SL Diesel swap.

http://www.peachparts.com/shopforum/diesel-discussion/320390-oil-cooler-lines-2.html

These are some ideas.

Another option is to source another 240D Radiator, and sell the Turbo one. I think this would be the cheaper way to go.


Only you know how you want your car to look..........However, if you decide to swap in a 617.952 engine, then the radiator and expansion tank is already waiting for it. :)


Charlie

So, I picked up an expansion tank along with it's associated hoses and the larger fan shroud at the local MB wrecker today. The oil cooler looks like it will hang on the side of the new radiator in much the same way as it did the old one, but I may find otherwise this weekend. I figured I would take some cardboard and make some patterns for the brackets to hold the expansion tank and then copy them in aluminium flat stock. I'll hold these in place and drill holes and shoot the holes with a little rustoleum and bolt them down, The whole passenger side of the engine compartment is a blank slate in the 240, so I figure as long as I get the top level of the tank about where it is in a turbo and get the tank about level I should be OK. I'm still a little worried about the oil cooler. Good thing I have a couple of pickup trucks that i can get to work in if everything fails...

I have a 240 d radiator that I got at a pick and pull if you want to pay shipping and take a chance on it.

Radiator installed
 

The radiator installation went just fine. It is only about 1.75" wider and that width all goes to the passenger side, so the oil cooler fits just fine. The only difficulty I had on this job was that I decided to do the alternator and power steering belts while I had the radiator and shroud out of the way and I have to say, I have worked on a LOT of cars but I have never had the sort of difficulty with brackets and idiotic adjustment mechanisms that I had today. I kind of get why MB provides these screw adjustment mechanisms, but they should have just kept it simple. They are totally unnecessary and just one more expensive thing to break, but I digress.

Because I didn't have a wrench the right size for the oil cooler lines and which would fit down there where they are, I opted to leave the oil cooler in the car. That gave me the predictable difficulty of dealing with the lower bracket in the car and it's another one of MB's needlessly complicated little contraptions. Anyway, it all went back together, I filled the system and started the car, warmed it up and there doesn't appear to be any issues.

I haven't yet dealt with the proper mounting of the reserve tank. I made several brackets this weekend with the kind of metal I was able to get from the hardware store, but I wasn't happy with any of them. I think I'm going to go see a friend who's a metal fab guy and see if he can weld in some decent hardware. Does anyone know of any reason I shouldn't weld on this car? I don't know if the CC computer is still good, because I've never really spent the time figuring out why the cruise doesn't work. I suppose it may make sense to remove that bit from the car before welding, but I can't think of any other computers on board.

For the moment the reserve tank is precariously located with bailing wire, as I couldn't find any of my large zip ties. :-(

You need to be careful with the placement of the tank. Too high and the hood will close on it and crack it.

I knocked up a bracket for the back ofthe tank with flat stock steel screwed to the wheel well and nut/bolt to the tank. On the front i used threaded rod with nut/bolt/washers. I just kinda knocked up all of this with stuff around the garage not sure if it would be strong enough but it's been holding fine for years.