Needing dd help

[83ChevyK5Blazer]

My daily 98 Nissan 200sx 1.6l manual, is fixing to get lit on fire!

I bought it a couple months ago for a cheap work car, ran great, 37mpg for a month. Coming home from work it got hot on me and boiled over, i let it cool down, cranked the heater and made it home.
Flushed it out, replaced tstat, and radiator cap as the seal on the old one was rotted out.
Took it to work that Monday, made it to work with no incident, in the way home it boiled over again, lots of water and cool down stops and i made it home.
I tested for hydrocarbons, and failed. No water in oil or oil in water visible.

Went ahead and did a head gasket, machine shop said they checked for cracks and decked it, installed it all, bled the cooling system out.

Since then it's good for 15 min or so at 45-60 until the temp comes back up over 220, I installed a mechanical temp gauge today on the hot side of the rad, it is coming up, down a bit, then back up.
Cooling fans are working properly, flow seems good, I'm bleeding air out of the cap and air bleed above the tstat housing.

Any ideas are welcome, this car is driving me insane.

 

[500$k5]

water pump?

 

[83ChevyK5Blazer]

Possibly, previous owner said he had one put on, it seems to flow by watching the stream out of the water bleed.

 

[70jimmy]

Check hoses for collapsing and water pump. After that look at heater core and core hoses. That's all I got.

 

[Wes Harden]

You said you checked for HC in cooling system and it failed. Does that you found HC or no HC found?

I would block check after it has over heated and see. Sometimes micro cracks only show themselves after freeway speeds or a really long time idling

 

[JoshHefnerX]

Ok, so you said 15 mins at speed and the temps are over, does it stay cool at idle, does it take longer to over heat at idle?

If it does, you may need a radiator. You are producing more heat at speed that isn't getting radiated off.

 

[83ChevyK5Blazer]

Idling it will come to 185, and sit there. Then about 10 min at hiway speed it will slowly start heating up and stay there until it is at idle for a while.

 

[tarussell]

Agree with all possibilities said up above but add checking to see if this thing is running very lean while at speed under a little load & RPM’s - just spit ball’n.

 

[JoshHefnerX]

Staying cool at idle, pretty much leaves the radiator or water pump being inadequate. Thermostat should be good as it will eventually open up even at idle, and if it's not overheating there that's working. So, not enough water flow through the system or not enough heat dispersion from the radiator.

 

[83ChevyK5Blazer]

I'm going to order both and we shall see later in the week.

 

[83ChevyK5Blazer]

Swapped out the rad and water pump. Will bleed tomorrow and see.

Found this bleed line stopped up, might have been trapping air in the water pump.



Hose was solid gunk and probably head gasket in a can from the po

 

[83ChevyK5Blazer]

So much better, blew a tire on the test drive, but nearly ready to drive out of my life lol

 

[JoshHefnerX]

Temp certainly is down by the looks of it. Was probably overdue for some attention. Sucks about the tires, they're not getting any cheaper. But at least you'll know what's on there and it's condition

 

[83ChevyK5Blazer]

It got to 190 on hills and stayed around 185 which is the thermostat temp, I'm guessing the rad was plugged up and there was air being as the bleed for the pump was blocked.