Just bought a 1992 F150. coolant leaking from an opening on the passenger side of the motor between the top and bottom coolant lines. I am flushing the system but not sure what else to do.

 

I'm really not sure what you're asking here? Your title says sludge in the cooling system, your post talks about a leak? I'm not sure what your arrow is pointing at either? Seems to be a bolt?

 

The upper and lower hose are for the throttle body, a small amount of fluid goes through there to warm it up. The hoses can come loose or you may have a damaged fitting where the hose attaches. You will want to stop the leak so it doesn't get on the alternator but other than that, probably won't cause any damage.

If you want to drain as much coolant out as you can, there is a plug on the driver's side below the 6 and 7 cylinders.

 

Very weird looking set up to me the upper and lower coolant hoses have others areas of reach into the intake in your 1992?

 

By the way the sludge may be your transmission fluid getting into your coolant from the lines that go through your radiator. If yours is set up that way. If you look at the radiator and see lines going out the sides and back in with a U shape you have a radiator with transmission cooler lines going through it. If they start to leak it allows small amounts of fluid into the coolant. When I got my truck the coolant was awful. I had it flushed and saw some oil coming back to the top after several months so upon the advice of a mechanic buddy of mine I bought a new radiator and that seemed to fix it. Been several months now and no more film on the top of the water. If it's not that I'd check your oil and make sure it's not a milk shake. If it is then you have head gasket problems.

 

Thanks for the info. It d have a transmission cooler and a new radiator. Suspect it to be a couple of years old. Mostly concerned about the spray at the engine. Vehicle is not running hot. Any idea how to stop the spray?

 

Could this be caused by improper coolant mixture?

 

Better idea of where spray is coming from

 

Can't really tell for sure in your picture, a close up would help but it looks like the small freeze plug is missing from the throttle body.

If so just remove and plug the supply and return coolant lines for the throttle body to stop the leak.
Or put in a new freeze plug.

You may or may not need it but that depends on your location, gets cold here well below freezing. One of my trucks had that system bypassed before I bought it, so far no ill effects without it.

 

in Georgia. Seems like the easiest fix. Do I have to plug the lower tube if I plug the upper?

 

Yes you have to disconnect and plug both hoses supplying the throttle body.

 

Thanks for your help

 

As for the open holes on the TB, I wanted to cap mine so I took some inspiration from the hipsters. I bought a pair of these plugs, filed them down and they fit perfect, look good too

Pair of Acrylic Ear Plugs Screw Fit Ear Gauges Flesh Tunnels The Punisher Skull | eBay