Om617 Question(s) - PeachParts Mercedes-Benz Forum

kingkong0192 · #1 09-06-2014, 07:19 PM

Totally new to diesels. Got a screaming deal on a running 85 MB 300sd with the om617. Always been into jeeps and I've read about the 5 cylinder diesel swap and when this deal came up I had to jump on it.

I plan on putting this motor in a jeep cherokee.

Started tearing the car apart today to pull the motor and I have some questions.

1. Vacuum lines. They're everywhere. It's insane. Is there any way to tell which lines I actual need/are vital to keep and which I can just cut out and get rid of?

Mostly over by the ABS pump I'm talking. There's so many.

2. Transmission. Should I pull the motor and transmission as one or try to split it? If one unit, is there an easy way?

3. Anything else I should know? Going to search search search in a minute here but I figured I'd throw up my own thread in the meantime.

Here's the beast.

vstech · #2 09-06-2014, 08:12 PM

Only thing vacuum is for on the 85 Engine swap wise, is transmission shift firmness and engine shutoff. Everything else can be sealed up.

Keep in mind the hose from intake to the valve on the firewall to the blue flying saucer, then to the IP is NOT vacuum! It's manifold turbo boost sense tubing... Be careful with it.

And, Welcome to the forum!

uberwasser · #3 09-06-2014, 08:33 PM

To help shed a bit more light, Mercedes used vacuum on these cars for much more than most manufacturers did. Vacuum door locks, vacuum pods for the climate control, etc.

The vacuum shutoff is integral with the ignition switch. Those who have done swaps like these have had to figure out a way to draw vacuum on the fuel shutoff valve when turning the engine off. You could make it as simple as having a tube in the car that you suck on to turn it off -- your passengers will just need a brief disclaimer

The transmission, as noted, is a more complex setup but it's "stand alone" in that it will move over with the engine and transmission and should continue to function as it did in the donor car. The only line that enters the car, if any, is a vacuum bleed off for the vacuum control valve on top of the injection pump. It's not connected to anything, just open to "clean air" in the cabin.

Best of luck!

gear-head · #4 09-06-2014, 10:50 PM

Where are you located? Kind of looks like the front seats are swapped from a second gen W126. Bet you'd like to sell off some parts from the remainder?

kingkong0192 · #5 09-07-2014, 12:22 AM

I'm not using the Mercedes transmission. Buying an adapter from the om617 to my jeep transmission. (Unsure if I want to go with a stick or auto yet.)

That means I only need vacuum to shut off the engine, correct? That seriously makes my life so much easier. Looks like I should have the motor out tomorrow.

The "blue flying saucer" is the thing directly in front of the abs pump correct? Ill keep everything that's attached to that in one piece. I also know I need to keep the glowplug electrical box thingy.

Sorry. Let me go add that to my profile. I'm in new milford, CT. If you need something say something. All I want is the motor and the seats. (They're way better than jeep seats. Haha.)

Thanks again for the wonderful forum. Ill keep you guys up to date with this one.

interzonearts · #6 09-07-2014, 01:22 AM

The service manual says you pull the engine and tranny together. That's what i did and frankly if there's a way to separate those two in the car it must be much harder then pulling them together.

The advice i got was to keep everything until i had the swap completed to my liking and it was a good one. I keep on pulling different pieces from the merc as the work goes on.

If you haven't figured out how to tackle the tach, you could consider getting it from the donor.

I used the metal fuel lines, some wiring, the coolant expansion tank, a whole bunch of clamps.

I'm also using the car for storage of all the bit's and pieces - after pulling out the nice and comfy seats

Once you decide on the transmission adapter you can ask the manufacturer if they have a swap guide to go along with it.

cooljjay · #7 09-07-2014, 03:07 AM

Hope this was in a front end accident, if not it was a nice color combo and sad to lose another to a Chrysler product

Stretch · #8 09-07-2014, 04:43 AM

Don't you need vacuum for the Jeep brake booster? (Or do they not have power assisted brakes...)

kingkong0192 · #9 09-07-2014, 04:59 AM

Yeah it was. When I bought it the headlights were already out because the PO pulled the frame straight enough to get the thing to move straight down the road. Hoods from a different car as well. Fan on the front is also slightly bent. Think I'm going all electrical though so I'm not worried about it.

Fret not though, I got a package deal. I'm sacrificing this one and keeping the coupe. (Pic related.)

Yes the jeep has a vacuum booster that will require vacuum. Honestly haven't figured out/looked into how I'm going to do that one yet but I figure as long as I have all the parts still around I can figure something about.

Dan Stokes · #10 09-07-2014, 12:00 PM

I suggest you read my build thread. I've already slain most of these Dragons! Oh, and convert to manual brakes if possible.

Have fun -

Dan

Stretch · #11 09-07-2014, 01:06 PM

Quote:

Originally Posted by Dan Stokes

I suggest you read my build thread. I've already slain most of these Dragons! Oh, and convert to manual brakes if possible.

Have fun -

Dan

Come on Dan don't be shy - give the chap a link to your thread!

kingkong0192 · #12 09-07-2014, 08:27 PM

Made a post last night, said something about a moderator needing to accept it, i don't see it yet so i'm not sure if post was lost in the abyss or still pending. Forgive me if this turns into a double post.

Quote:

Originally Posted by cooljjay

Hope this was in a front end accident, if not it was a nice color combo and sad to lose another to a Chrysler product

It was indeed in a front end accident. The PO removed the headlights when he pulled the frame straight again to get it to go straight down the road.

I jacked the front of the car up today to set it on jackstands so i could disconnect all the transmission/drivetrain related stuff and realized that the frame rail is totally squashed and weird looking. Definatly hit pretty hard.

The fan on the front of the motor is also slightly bent, but i plan on going all electric fans i think so that shouldn't be a problem.

Quote:

Originally Posted by Stretch

Don't you need vacuum for the Jeep brake booster? (Or do they not have power assisted brakes...)

Yes. I'll figure that out later though. Honestly haven't looked too far into it i'm just getting everything i need from the mercedes first.

Quote:

Originally Posted by Dan Stokes

I suggest you read my build thread. I've already slain most of these Dragons! Oh, and convert to manual brakes if possible.

Have fun -

Dan

The s10 thread? Going to read through it when i get a minute here.

As for the mercedes i got just about everything disconnected and then it got dark. Actually i forgot the linkage that goes to the gas pedal. All the vaccum lines that came off the IP i was super careful with. Wasn't exactly sure which line i needed so i treated them all with care.

BillGrissom · #13 09-08-2014, 02:35 AM

I think you need vacuum just for engine shut-off and possibly for the "turbo fuel enrichment" function of the "ALDA Valve" on top of the turbo-pump. I don't recall if the later requires vacuum, plus some people here recommend removing the ALDA, so read up.

You will need a way for your key switch to apply vacuum to the "stop valve" on the turbo-pump. A manual valve on the M-B key does that. You probably need an electric version, connected to your IGN circuit, and I think must be "single pole, double throw" type in electrical parlance, i.e. must switch a port between vent and vacuum.

About half the vacuum controls are for the EGR, which most people remove (see posts). You can also remove the EGR valve and install block-off plates (RollGuy here sells cheap). The other half are for the transmission shifting. You can remove the white VCV on top of the IP (w/ linkage to "fuel pedal"), the "blue saucer", and everything else in the tranny circuit.

Finally, the alternator is a "Motorola type", as used for decades in GM cars. It requires a "boot-up" current to get the field going. It gets that from 3 dash bulbs in the M-B. You could supply that current thru a resistor. That is the D+ wire. I don't know how it routes in the 300SD.

interzonearts · #14 09-08-2014, 10:00 AM

Quote:

Originally Posted by BillGrissom

I think you need vacuum just for engine shut-off and possibly for the "turbo fuel enrichment" function of the "ALDA Valve" on top of the turbo-pump. I don't recall if the later requires vacuum, plus some people here recommend removing the ALDA, so read up.

As far as i understand it ALDA does't have anything to do vacuum except for when the boost exceeded 15psi or so. At that point some engine protection unit shoots vacuum into the ALDA and reduces the fuel delivery to no boost.

toomany MBZ · #15 09-08-2014, 02:30 PM

The ALDA does not use vacuum at all. If the switchover valve senses too much boost, it will bleed pressure from the intake manifold. This is an electrically operated engine safety device.

In the OPs case, vacuum is used only for shutting the engine off. The brake booster line from the vacuum pump needs to be connected the booster.

The blue flying saucer is part of the automatic transmission (at least) set up. You won't need it.