1982 300 D resurrection thread

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I've been asking questions here and there on the site but I thought it best to combine everything into one thread.

I have owned a number of VW NA/TDI and Cummins 12v diesels in first gen Dodge trucks over the years but never a Benz diesel. Last Benz I worked on was in the late 80's and it was a gas "stacked headlight" car with twin Zenith carbs. Anyway....

My son wanted a diesel Benz project and my philosophy has always been to buy out of state sheet metal and deal with the mechanicals. We are in the rust belt and saw a lot of bondo buckets and fresh primer/paint jobs so we settled on a California car that needed some body work after an accident. It isn't minor, it moved the cowling slightly and tipped the front wheel inwards but the rest of the car is very solid.



It had been just driven in from California this spring and was driving the day it was hit so theoretically it should have needed little mechanically. It was very cold when we looked at it and it had been sitting for weeks but it did fire up on a single glow cycle. It ran kind of rough and "lumpy" but I've always thought that a good cold start on a diesel means good compression and a good place to start.

So we bought it and had it hauled home on a rollback, it ran well enough to get it on and off as needed and we stowed it in the barn.



Digging into it, I discovered that the air filter bracket was missing the back "leg" and the hard plastic C shaped pipe to the turbo was loose at the turbo end, the entire filter/housing assembly was rocking around in the engine compartment. There was a lot of oil residue and the air filter was quite clogged.



I took everything related to the filter housing and piping apart, cleaned it out, and bought a replacement OEM filter bracket (with all three legs and new isolators!) from a member on here, replaced the air filter, and put it all back together.



I also changed both fuel filters, which were quite dirty.

Last night was the moment of truth for seeing how it started and ran after all this initial work had been done. The front end is blocked up to deal with the front suspension (more on that later) so this was just a start and run test.

It had been sitting a few weeks in the cold so it took two tries to start and once it started, even after allowing for time for any air to purge out from the filter change (I did get the pump to work). it didn't run all that well. Fortunately, my son was watching the engine compartment while I was in the car (can't get out the driver's door) and he noticed a little diesel from the bolt on top of the main filter housing. I tightened that up and tried it again. It started much better and ran much more evenly. Little to no smoke and I would have seen it in the barn if there was.

The oil was pretty dark, and I don't know if a Benz is like a VW where the oil usually gets black in a hurry or like a Cummins where it takes some time and it doesn't get that dark. I knew the PO used 5w40 Mobil 1 so that was good. Regardless, we were going to change it because we didn't know when it had been done last. I used some 15w40 Valvoline oil as "sacrificial cleaning solution" so we filled with that, ran it for a while, and changed to the "final" Rotella T6 5w40 after removing the oil filter and cleaning the inside of the housing, and installing a new filter.

There is a pretty significant dent in the oil pan so we are going to pull that off and replace it with a new one purchased from Pelican, along with a new gasket. (Yes, I know we should have done that when we changed the oil but it was getting late and cold and we were running out of time. We'll just catch the T6 in a clean container and reuse it).

I fired it up once more and it idled nicely and reacted fairly well to the throttle I suppose. I have no experience with how these things are supposed to react, I only know they are slow, so I may have to wait till I can get the front end fixed and drive it up and down the driveway a few times.

Based on what I saw in the fuel fliters, I think it would be best to run a few filters worth of diesel purge through the injectors to clean them up a little. I have a can of Moly diesel purge I got with a TDI years ago so I have it available and this seems like a good place to try it.

I've added some white bottle (Winter) Power Service to the tank, it appears to be about 1/4 full. I've always used Power Service on my other diesels winter and summer with good results. I do have a bottle of the Howes additive based on some comments here but I've not used it yet.

Next, I have to deal with the front suspension damage. The body does not appear to be affected in the area of the suspension (guide rod for example), it just appears that the wheel was hit and the steering knuckle bent inwards in the middle of the unsupported span, which is what caused the wheel to tip inwards at the top. You can see how close to the shock the steering knuckle is, there is 3 or 4x the clearance between them on the other side and there is an impact mark from the inside of the wheel on the steering knuckle.



I have a replacement steering knuckle provided by another member and I'm having a Lemforder lower joint pressed in at a local import shop a buddy owns. I'll be picking that up today, I have a Lemforder upper control arm assembly purchased on here to put on as well.

I've replaced Jeep suspensions before but nothing like this one. My plan is to block the lower control arm in place where it is and remove and replace the UCA, steering knuckle, and go from there. I'm open to suggestions and comments on how to safely do this if there is a better/smarter way. Hopefully, this gets the front wheel back where it needs to be and makes the car safe to drive a little up and down the lane. I know an alignment will be needed but hopefully this gets me in the same zip code.

A member on here has found a nice replacement fender and door the same color in a California junkyard but I want to be sure we have a solid engine and front wheel situation before we get into cosmetics.

Although it would be nice to not have to crawl in the passenger side door to get into the car. I'm nominated for that since I'm only 6' and my son is 6'6", haha.

I also need to find out exactly where the vacuum line for shutoff is damaged or come loose because we need to use the lever on the IP to shut it off, but that's down the list.

That's the story so far, we're trying to keep the old girl on the road. I'll update as things get better or go south.