1989 6 speed overheating question
 

I think I know the answer, here goes

When the car is parked there is leak from the middle(ish) area of the engine. It will take 2-3 days before the leak is visible on the ground. I checked the radiator hoses, (even though the leak is behind that closer to the TPI and AC) no visible leaks.I checked the heating hoses no visible leaks. I don't have heat, my heater core is leaking, I cut the in and out lines in front of the firewall and put a u shaped tube on there to bypass it years ago.

When driving car gets hot very fast, the fan is working fine. I could smell antifreeze today when I pulled over and opened the hood but didn't see any leaks.

I am guessing the water pump is the possible culprit?

Water travels weirdly so please don't assume. You have two issues here; leak and over heat. They may be related.

My thought is to first get a pressure tester on the cool radiator cap and build pressure to about 18 pounds. Your leak should be visible at that point.

The over heating could be caused by lack of fluid (from the leak) but I 'd first check to see if you have any obstructions on the front of your radiator. There is a "void" between the AC condenser and the radiator where leaves and debris collect. It would not surprise me to hear that you find that area pack with junk. Vacuum or flush out and improve your air flow.

I checked for debris before, I double checked and it's clean. I removed the radiator cap and started the car, I could see some fluid movement then saw some bubbles. Around 236 degrees the antifreeze started to get sucked down and around 239 steam started to come from the neck, no white smoke or anything crazy just steam and of course the coolant was boiling.The upper radiator hose was hot and the lower ice cold. I would assume the thermostat is working. I think this car needs a coolant flush as it's a light brown color. The low coolant light was on for a few min then went off, I checked the levels it seems fine.

I removed the plastic covering and the air filter to get good access. You where correct there was leaves and some dirt. I vacuumed it out as best as I could, I need to find the nozzle for my compressor so I can blow out the stuff I cant reach with vacuum.I ran the car at idle for 20 minutes got to 244 then fan kicked in and temp slowly started dropping got to 227 then I started revving engine at 2k rpm's it increased fan kicked back in and never went above 237. Definite improvement, I still have a small leak some where, I will pressure test or go get under the car do a close inspection to find it.I noticed the fan directly behind the bumper wasn't running, IIRC that is for the AC.

That doesn't seem right … if the T-stat and water pump were working there would be hot flow through both hoses. The bottom hose should be warm.

When the T-stat is open you should be able to see coolant flow with radiator cap off. If not I would replace the T-stat.

Pressurize the cooling system first and address the leak. If the thermostat is in question, replace it with the correct o.e. temp thermostat and go from there. You have to make sure the cooling system is up to par before diagnosing any possible issues.

I haven't had a chance to get a pressure test kit plus its freezing in my temporary detached garage. I pulled the thermostat since it's a easy fix. It looks brand new, I must of done it when the intake manifold gaskets where replaced. I boiled a pot of water stuck it in and it opened up, I didn't have a thermometer so I just waited for a boil since it had to be 212 degrees. I can eliminate that issue. Car was cold and it was 30 degrees out, I started it had car in neutral, in 2 min the temp was already at 135. The rad could be clogged but looks real clean I am guessing it's the water pump or the bad coolant. Once this artic freeze pass I will check again.

I didn't do a pressure test, There is a pool of coolant under the water pump and I have confirmed it is leaking from the water pump weep hole. Is it recommended to use any type of sealer on the gaskets? I was thinking maybe a dab of permatex thread lock blue on the 4 bolts.

Was thinking this for the gasket since it won't harden.
https://www.autozone.com/sealants-gl...alant/526681_0

I used Permatex on the bolts & gasket with no leak issues over many years.

Might as well replace that pesky lower hose while in there that far, IMO.