89 300E Clunk and Oil Pressure question and minor repairs I have done

I bought this car used with 80K miles now has over 100K. I have replaced the following: -Alternator (actually replaced by dealer at time of sale) -Radiator
-Waterpump (note: difficult access to bolts, required bending a wrench and several small ratchet swivels and extensions) -Fuel 'Governor' (gas smell was due to slight leak (yipes) from this small black box bolted to the back of the throttle body/intake) Belt idler pulley assembly ($90 if that bearing goes bad!) -I have a new secondary water pump I need to install. The heater quit blowing hot air, but tapping on the solenoid (metal cylinder near the battery same compartment)freed that up and now its fine -Throttle micro switch (small plastic wheel breaks and causes it to idle high) -I also have a new door check to install, one door wont open all the way and I'll need another one eventuall, but the drivers side door check completely broke, the old one came out easily and the new one will go in easy) -2 window switches - A/C wont get very cold, but does get a little cooler when I add freon. - 4 new tires
Question: I turn the key on and the oil pressure guage goes all the way to max. Never changes, even when car is running. Has someone bypassed the oil pressure sending unit, I can believe this is normal?
And the worst part: Returning from a long trip (650 miles both way, oil changed a couple weeks before trip) after exiting the highway, I now hear a slight metallic tapping sound. It is not very loud. It does speed up with the RPM's but doesnt necessarily speed up proportionally if that makes sense. I know that normally this could be a crankshaft bearing wearing out and disaster on its way, but could be it anything less critical, such as the oil pump, or oil pump chain? It almost sounds like a spark arcing to ground too, but I don't have any performance loss.
Any advice appreciated, also, any leads on a 3.0 inline 6 cyclinder engine block in florida.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
OIL sending wire grounded?
the case, minus a few cans!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.