I have a 83 300sd that needs the oil cooler lines replaced.Can i remove and cap the fittings on the filter housing without any problems. I use it for a short commute less than 100 miles a week

Removing the top cap on the Oil Filter Housing is how you change the Oil Filter. On the bottom of the tube attached to the Cap is 2 O-rings that need to be occasionally changed especially if they are hard. So yes you can remove the Cap if the top of the Oil Filter is what you are speaking of.

However, that has nothing to do with the Oil Cooler Lines which one way or another need to be replaced.

You will need a wrench that usually needs to be thinned in order to fit between the Oil Cooler Housing and Oil Cooler Hose to hold the fitting.

On the turboed Engnes I would say that you need to have a functioning Oil Cooler and Hoses because the Oil is sprayed up into a chamber inside of the Pistons in order to cool them.

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84 300D, 82 Volvo 244Gl Diesel

He's asking if he can remove the LINES and CAP (plug) the inlet/outlet at the oil filter housing...

I've seen people bypassing the oil cooler (done it myself in fact), on a temporary basis by running a loop of hose from the inlet to the outlet, but never anyone capping it off. Someone who knows the internals would have to comment on that.

I would just use this method:

http://www.peachparts.com/shopforum/diesel-discussion/205012-cheap-oil-cooler-hose-replacement.html

If I was going to do anything temporary.

-Rog