'87 300e love hate relationship

[manich]

Hey everyone,
My 300e has her good days and her bad. (More good than bad thankfully) However, it seems like this last month she's really let herself go. I have an ongoing problem with the tach:
12v lead is good, replaced the tach with a working one so its not mechanical, problem is most likely the plug in the rear of the tach but I cant figure out where it originates from.

Also, two days ago I started smelling a sweet burning smell, similar to lilacs. There is no smoke and the smell is only in the cabin and tailpipe. No loss of coolant, but I noticed a lot of oil in the hose connecting the head to the air filter and a circle of oil in the filter. I'm thinking it may be the heater core but I haven't used the climate control in about two months.

Any help would be appreciated as I love my MB but (like all my relationships)it seems like she always needs more of my attention

-Matt

[J.HIDALGO]

you have a heater core is leaking or the evaporator. Very common in these cars. Are they original...?

J.H.