'85 into '83 300D swap - PeachParts Mercedes-Benz Forum

GlennCraven · #1 06-22-2006, 12:27 PM

OK, related to my other thread about the blown head gasket, the indy mechanic has the engine out of my 1983 300D turbo and the 144K-miles engine delivered from the 1985 300D turbo at the salvage yard. But he's run into a couple of problems.

He says the turbo on the 1985 has an electric servo that my '83 doesn't have. He says my '83 turbo could probably be swapped for the '85's unit except that my '83 turbo is going bad (leaking oil). ... So the salvage yard is trading me (no charge) a serviceable '83 turbo unit (off a 213K-miles car) in exchange for the return of the unit on the '85.

Does that sound like the right choice? Could the 1985's unit just be left on?

The indy also says the injection pump appears to have an electric shutoff on it for the 1985 vs. the '83 which has a vacuum shutoff. ... One of the wires off the '85 injection pump goes down to what looks like a "crank solenoid," and apparently the '83 has none of that.

Again, the salvage yard has volunteered to send the injection pump off the 213K 1983 in their yard at no charge for returning the injection pump off the '85.

Will these parts swaps work? ... Has anybody done this before?

When it was run through the computer at the salvage yard, the 1983 and 1985 engines were considered directly compatible, but I suppose nothing ever is. ... But are we going about it as best we can at this point?

Thanks.

dieseldiehard · #2 06-22-2006, 12:45 PM

The shut off is a vacuum in either case, but there is a small difference in that the 85 has a different transmission and there are some small items that are associated with that that the 83 doesn't need. Basically the 85 engine will fit the 83. But the turbos are probably different, the 85 uses a vac assist to control shifting, so you would need the 83 turbo on the 85 engine to make it fit your car.
The '85 torque converter is also desireable for it has a higher stall speed spec.

DeliveryValve · #3 06-22-2006, 07:29 PM

I am basically doing the same swap. Instead the donor vehicle is an '84. So are saying that this turbo will not work in my '83? Couldn't I hook up the vacuum assist to a vacuum source and be done with it? See pic... (I am replacing the pan gaskets and my engine is on the stand upside down) I have the vacuum assist underlined in red and blue. Yikes! I thought this would be a straight up swap!

DeliveryValve · #4 06-22-2006, 07:34 PM

Ok now for the injector pump!?!? So this is the electronic part right?Underlined in Blue....

Now what is this part (sensor) next to it underlined in red. It is hooked up to block and my '83 only has a screw in plug in it. Any insight with this swap would be very appreciated!!

DeliveryValve · #5 06-22-2006, 08:49 PM

Ok here are more pics of what I am talking about in the previous post. This is taken from my '83. Notice the plug on the block that I circled blue. And the next pic is a close up shot. So what is this sensor on the '84 engine used for?

The last pic is my current '83 turbo setup.

Like I said earlier, any insight to this swap (basically what else I have to do) would be very appreciative!

GlennCraven · #6 06-23-2006, 01:20 AM

Those are similar findings to what the indy mechanic found with my '83 to '85 swap. We went with a different '83 car's turbo (trading the '85 turbo back to the salvage yard straight-up) and a different '83 car's diesel injector pump, too. Again, straight trade with no cash since I'd bought the '85 engine from them and not all parts would work.

I do wish somebody'd come along and answer your specific questions, though, because it would be nice to know.

Motorhead · #7 06-23-2006, 01:49 AM

The box on the inj. pump is hooked up to a control box that is usually located inside the car behind the right side kick panel. It has something to do with the control rod in the injection pump. Bosch used the same thing on Cummins 12 valve diesels in the Dodge trucks with the inline pump.

my123ca · #8 06-23-2006, 12:39 PM

It is called the rack position sensor and one of the inputs for the egr control unit. You can have that there with no effect on drivability. I have that on my car but the EGR disappeared for a while

I dont know any thing about an electric servo in the turbo of an '85. He must be talking about the air recirculating valve which is controlled by a switchover valve and controlled by the EGR control unit. Some have theirs disabled with no problems reported. I think you can transplant the '85 engine with no problems as long as it fits the engine mounts. I wouldnt replace the turbo or the injection pump. I would go for the original from the '85. Most of the problems mentioned are emission related.

DeliveryValve · #9 06-23-2006, 01:32 PM

Quote:

Originally Posted by my123ca

It is called the rack position sensor and one of the inputs for the egr control unit. You can have that there with no effect on drivability. I have that on my car but the EGR disappeared for a while

I dont know any thing about an electric servo in the turbo of an '85. He must be talking about the air recirculating valve which is controlled by a switchover valve and controlled by the EGR control unit. Some have theirs disabled with no problems reported. I think you can transplant the '85 engine with no problems as long as it fits the engine mounts. I wouldnt replace the turbo or the injection pump. I would go for the original from the '85. Most of the problems mentioned are emission related.

Ok.. You have to hold my hand here

...

Would I just leave the electronic piece on the injector pump not hooked up to anything and run with it?

Or do I go ahead and get that "control box that is usually located inside the car behind the right side kick panel" as stated my MotorHead?

Personally I would rather run the '84 turbo the inlet seems to be a bit larger then the '83s. So it would seem I could just do that and have the air recirculating valve disabled. So then my worst case senario would be just to transplant my '83's injector pump on to the '84 engine.... And do it while it is not in the car!

my123ca · #10 06-23-2006, 06:40 PM

I dont know if the '83s have any EGR and if it has one -how its being controlled. Your car will start and run with the rack position sensor unhooked. Its one of the inputs that control the EGR. If you want the EGR to work on the '84, then I GUESS you will need that box inside the kickpanel or if you had an EGR in the '83, maybe it could just be plug and play.