It's Running Again! 84 300SD - PeachParts Mercedes-Benz Forum

Graplr · #1 10-09-2008, 02:42 PM

I got my SD on the road again! I replaced both the engine and transmission. It has been a long road but I'm almost there. I took it out for a 5 mile freeway run today!

After I got all the adjustments made and the fluid levels correct on the transmission it worked great! I had the transmission shipped to me from a salvage yard. I had my fingers crossed the whole time but it works just as it should.

The engine is a 617.952 that I actually pulled from a 116 300SD. The engine had been transplanted into the car.

The biggest problem right now is I have a pretty good sized oil leak. It is coming from somewhere around the back of the engine. Perhaps the oil filter housing. I put a new gasket in there. I'll have to check into it some more. It is very substantial. Probably a drip every second.

Also it won't shut off. I found a vacuum line coming from the shut off valve the is not connected to anything but I can't find anywhere to plug it into.

Also my tach is not working. I actually drove the 116 before I pulled the engine and the tach didn't work on it. I assumed it was the tach barrel. I reused my known working tach barrel from my 84 300SD. So that must mean it has to do with the sensor in the front of the engine right?

I'm really excited to get it back on the road!

Hopefully by tomorrow it will be my daily driver again!

Dee8go · #2 10-09-2008, 02:50 PM

I would think it would be your sensor, too. It sounds like you're well on your way. Good for you!

vito · #3 10-09-2008, 04:21 PM

Quote:

Originally Posted by Graplr

The biggest problem right now is I have a pretty good sized oil leak. It is coming from somewhere around the back of the engine. Perhaps the oil filter housing. I put a new gasket in there. I'll have to check into it some more. It is very substantial. Probably a drip every second.

I'll bet it's the oil pressure sending unit. Cylinder looking thing that screws into the oil filter housing. Notorious leaker.

Graplr · #4 10-09-2008, 04:45 PM

Quote:

Originally Posted by vito

I'll bet it's the oil pressure sending unit. Cylinder looking thing that screws into the oil filter housing. Notorious leaker.

Thanks, but I don't think it is the sending unit itself. I reused the same oil filter canister and unit (since the one on the 952 was a mechanical one) and didn't touch the sender and it was not leaking before had. My guess is it is the oil canister where it attaches to the block. I'm hoping the I just need to tighten a bolt on the oil filter housing. I've had so much go wrong, I'm due for a touch of something going right!

rrgrassi · #5 10-09-2008, 04:51 PM

Did you make sure the mating surfaces and the gasket were all good and smooth? Anything not right with that sealing area will result in a leak.

toomany MBZ · #6 10-09-2008, 05:09 PM

The tach in 84's and 85's takes their signal from the transmission, not the crank sensor, there is no tach amp.

Graplr · #7 10-09-2008, 05:19 PM

Quote:

Originally Posted by toomany MBZ

The tach in 84's and 85's takes their signal from the transmission, not the crank sensor, there is no tach amp.

Well, I have a black round thing that has a gray cord that plugs into it. It was there when I had the original engine. And the gray cord ran to the front of the engine. It is the same thing on the 952 engine in the same location and it had a tach amp, just larger than the one in my 84SD.

So I'm about 98% positive I have a tach amp.

winmutt · #8 10-09-2008, 07:08 PM

Pray your leak is not rear main seal.

Graplr · #9 10-09-2008, 07:29 PM

Quote:

Originally Posted by winmutt

Pray your leak is not rear main seal.

Well the thing is, I drove the 116 300SD about 200 miles before I pulled the engine out of it. I know this oil leak was not present then, so it must be something I changed which is the oil filter canister or some of the return tubes. So it must be one of those. I hope to get a peak in there tonight.

jt20 · #10 10-10-2008, 01:33 AM

Quote:

Originally Posted by winmutt

Pray your leak is not rear main seal.

pray your leak is not the rear end of the head gasket either

Graplr · #11 10-10-2008, 09:51 AM

I got it up on jacks in the garage last night. It appears the leak (well, one leak, there may be more) is coming from the turbo return tube bolt where it enters in to the oil filter canister right above the oil pressure sender. It is dripping from the sender, but it looks like the oil is dropping on the sender from the bolt above. When I put this bolt in when I had the engine out, I think I may have crushed a washer. I'm going to go to the dealer today and get a couple washers and replace them. Anyone know what I should torque this bolt down to so I don't crush them again?

It also appears that a small leak was coming from the air filter housing where it meets the oil return tube. I left one of the air filter mounts off so it was not sitting level. I put the mount back on and now it appears to mate well.

I hope these are the only oil leaks. If they are it will be back running full time tonight!

Graplr · #12 10-10-2008, 09:53 AM

Quote:

Originally Posted by jt20

pray your leak is not the rear end of the head gasket either

Well again, that would be something brand new as this did not leak before I pulled the engine and I didn't mess with it when the engine was out. So unlikely, but of course I still am sending some prayers out because you are right, that would be be bad!

Graplr · #13 10-10-2008, 06:46 PM

That fixed the leak! Two new washers on the rear banjo bolt fitting on the oil filter canister. I took the old bolt out, very little oil dripped out. Put the washer on, pushed the hollow bolt through the banjo fitting and put the other washer on and cranked it down. No more oil leak!

The tach still isn't working but I haven't looked into it. I will probably start by swapping the sensor at the crank from the old engine to the new one.

And I still haven't found where to plug the extra vacuum line in so I have to shut it off by hand under the hood.

I'm doing a coolant flush right now and will get the good stuff in tonight.

I just drove it 40 miles and no problems other than a shutter. I'm due for new tires, so I'm going to get some put on tomorrow morning.
We're going on a 300 mile road trip this weekend. Just in time!
I'm really excited to get it back on the road.

mobetta · #14 10-10-2008, 09:33 PM

good work... it's a chore, isnt it.

on the tach- the 84's and 85 dont have the tach amp- but they do still have the gray 3 wire going to the front of the engine- it just is not connected to anything under the screw off cover.(tach amp is about 1.25"D x 2"h)
I wonder what year the 617.952 is?? you may have a bit of a chore to mate an earlier tach amp equipped engine to a later car, I dont really know. maybe swap the pickup from your 84 engine??

I missed something, though. What happened- did that oil cooler line snaffu take out your engine?

Graplr · #15 10-11-2008, 12:56 AM

No, the bad tranny took out my engine. It might have been weakened by dropping my oil. My tranny started leaking fluid and was intermittently working. The last time I drove the SD it wouldn't shift out of 1st and I was trying to make it about 3 miles home. The rpms were running really high. I think since a PO took out the switchover valve from the turbo to alda, my turbo blew and the engine blew with the extra forced air. I have a switchover valve on the new engine.

How could my 84 get it's signal from the tranny? There was no extra cord or anything like that. Both tach amps look identical in both cars except the 84 is a bit smaller. I am having a tough time believing that it is not a tach amp and that I used to get the rpm signal from the flywheel...
I guess I will first try and swap the two tach amp looking things to see if it works, then I'll try to swap the sensors.

The 952 engine has a low serial number. I did a bunch of VIN searching one day and concluded it was an 82.

I found the loose vacuum connection and now it turns off like it should.

I finished my flush and got Zerex back in there.

Really only thing left is fixing the tach....I'll tackle that next weekend. I'm due for a break!

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