After work I was changing the oil in the 1970 220D. everything was going good, I put the oil filter in the canister, put it back on the engine, drain plug is in, I put in 1 gallon of oil, went to grab the other container of oil and I see the Pre-Filter still sitting on the old oil filter. I am assuming I am not the only person that has done this.

Does any body know if it will be ok to leave it out in till the next oil change?

Thanks
Kevin

No, it must be in there.

Sounds good I will put it in.
I was not having a good night, so 1 more question.
Does the open part of the Pre-filter go up?
Some times wait I think is correct is not.

Again thanks
Kevin

Yes,the open end on top....
Another very important thing-the plastic one is NOT the pre-filter,it is the main one.
The big cylindrical one is just a by-pass one,the oil that passes thru it comes back via a throttled hole back into the oil sump.Running the engine without either of them is not advisable.
Here`s how they operate:
http://www.pauldrayton.com/uploadfiles/merc/Service/W123/w123CD2/Program/Engine/615/18-005.pdf

If you buy a Knecht/Mahle plastic filter,have a close look at the outlet(6 rectangular) openings-sometimes the moulding is so awful that several of them may be closed...get them open...

I have to say that this is one of the stupidest designs I have ever seen for an oil filter. At the age of 14, when I "took over" maintenance on my dad's 240D and did the oil changes the main (plastic) filter was MISSING! So, at some point some sloppy tech did what you did, left it out and just never bothered replacing it. I have no idea how long the car had been driven prior to that without the main filter installed. Of course I had no way of knowing it even belonged until some time later when I bought the shop manual and saw what is supposed to be in there. By then the car had probably been run 40K miles without the filter working right. I wonder how many cars drove around either with that main filter missing or installed upside down and doing nothing?

That combined with the "guarantee of an oil shower" every time you dropped that can down made doing a simple oil change into a real hassle. What were they thinking? The later (topside) cannister on the 617 is such a great improvement - though still not a spin-on filter it at least was doable without coating yourself in black oil. To top it all we had to do O/C every 3K miles back then...it seemed my hands and arms were always stained from the oil until I sold the car back in 1980.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

I am very happy I asked no I have all the info I need.
Yall are great
Thanks
I hope this info will also help other 220D owners

Last question on this one
In yalls opinion wait should I clean the plastic filter with?
The file above says use benzine to clean the filter.
I was thinking of using diesel fuel.
I called the auto parts store they said use brake cleaner.

benzine=gas

some solvents will disolve plastic so be careful and test whatever you use first to make sure it doesn't melt it. I don't think Benzene = Gasoline but was once an additive to Gasoline. I would think Diesel Fuel would do an OK job too.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Yeah, diesel fuel works just fine. I always dropped the plastic filter into a glass or stainless beaker just a bit biger than the filter's OD and barely covered it in diesel. Couple of good sloshes and dump the diesel and do a second time. Fish the filter out of the empty beaker and flail it about a bit to "centrifuge" the majority of the clinging diesel. You are ready to return it to service. Worked well for the 220D during its 20 year service.

By the way if you hold the canister up against the flange after loosening the center bolt a bit, the oil will mostly drain out around the bolt and make the job way less messy.

__________________
1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150

By the way if you hold the canister up against the flange after loosening the center bolt a bit, the oil will mostly drain out around the bolt and make the job way less messy.[/quote]

That sounds like a good idea

I cleaned the plastic filter very good it was nasty.
I am thinking about changing and cleaning the filters 1 a month for the next couple months to clean all the crap out.
I was shocked with all the dirt-grime on both filters.
I changed out the oil pan with a new one about 6 months ago and the old oil pan was very clean on the in side.
Before I got the car from my dad he used Castrol GTX for 22 years
now I am using Mobil Delvac 15W40