I have a 1989 318 that is overheating at idle. 173000 miles Haven't driven it because of this. So don't know if it will cool off while driving.

Noticed when I bought the truck that the water pump and timing cover had excess amounts red RTV. Someone was in there.

I replaced the thermostat with a 190 degree. Found a 160 in there.
Replaced the radiator cap with a 16 lb that tested to 14lb.

Used a scope camera to look in the radiator. Not super bad but used radiator flush twice. Camera showed some rtv stuck . Removed radiator and reversed flushed. Now clean and had good flow.

Thought that the wrong water pump could have been installed. Hard to tell with the scope camera. So I removed it. It was a six blade impeller like for a/c. The pump rotation is clockwise.

Opened up the timing chain for inspection. The crank had three keyways. It was set on the center or 0. Both marks on the gears were at 12 o'clock with #1 cyl @ TDC. The marks are 6&12 when #6 cyl is at TDC.

Not reassembled due to not finding a creditable cause.

I did have some moisture puddle under the tailpipe when the truck was running. Don't drive the truck much it a backup. Wanting it to be come a reliable back up.

Also I have a freeze plug on each side showing signs of some leaking.

Would you pull the motor to fix the freeze plugs replace head gaskets and inspect?

Or

Would you just reassemble and replace the thermostat with ones that has a bypass holes drilled it it? The 190 That I installed had the little brass wiggler bypass. Then do compression check to test the head gasket? And go from there.