Hidden in one of those blocks of text in the first post:

That's one of the things that made my brain go right to a combustion leak.

 

If you had a combustion leak bubbles would bee seen going into overflow bottle while running. If radiator cap is good. Rephrased. All possibility of any other cause should be covered b4 jumping into major repairs.

 

Cooling system work by pressure if its not holding any boil going to occur .....

https://www.yourmechanic.com/article...tyler-kirkland

 

Do you have the correct psi radiator cap and is it holding that pressure?

 

Just throwing this out there, be weary of your aftermarket radiator caps. They usually SUCK. Watch the cap as you tighten it down. If it's not properly engaging the filler neck it's going to eat up the plastic and not seal properly. I had to bend the tabs in on my cap to ensure a good seal.

 

ugh this is such a ****ing head ache

Alright I'll add new rad hoses to the parts pile

I'll just remove the goddam ****ing thermostat ***** ****er I don't think it's working right anyways the top radiator hose was getting hot but the engine wasn't anywhere near 195

 

Thanks everybody for the help this is exactly the kind of advice I was hoping for!

THANK YOU!!!!

Yay somebody read my super long and boring text! I assumed that the water was actually boiling and I haden't yet thought about it being exhaust gas blowing into the system. I'm trying to remember if I had the motor running while I popped the hood and check it out... I think I had the motor off at that point. Then I turned it back on, drove across the road to a better/safer spot, popped the hood again and let it idle and observed the engine bay. The boiling stopped and the electric fan even stopped spinning once it was to a happy temperature.

I have no idea, I just picked up one from Oreilly's but apparently they're pieces of ****ing ****.

...

If all of this trouble has been cause by one ****ing radiator cap I swear to god I will run that ***** over with my new bigger tires

 

What pressure should the cap be?

 

16psi

 

Stant or Carquest radiator caps are usually pretty reliable.

Nobody said anything about major repairs yet. We're just testing at this point. I would much rather test first to narrow down and rule out the obvious before spending any money on parts.

Suppose it's not a head or block issue. All he's out is the cost of the combustion test fluid.

Suppose it is a head or block issue, but he throws other parts at it first. All that will be a waste of time and money that could have been avoided.

Swapping the radiator cap is a good, cheap idea. Hopefully that will fix it. Unfortunately I don't feel optimistic. Ruling out a combustion leak with cheap and easy tests would result in less pessimism.

 

Its a what ?


Replacing maintenance items is never a waste of time or money.

 

Unfortunately the radiator cap was functioning perfectly.

I got the radiator pressure test kit and testing the cap. 16psi, held it for the three minutes that I left it on there.

Next I used the kit to test the whole cooling system minus the cap. Pumped it up to 16psi and thankfully it did not leak one bit. It held the pressure for several minutes. Then, with the pump still attached, I removed the coil plug from the distributor and cranked the engine for several seconds to see if the needle on the pressure gauge would go up or down, which would tell me if the head gasket was allowing air into or out of the cooling system. Thankfully the needle didn't waver one bit.

I can do the compression test still if you guys think it's necessary, but it will be more of a pain and take longer than other tests.

So, back to square one. Flush the **** out of the engine coolant passages and put in a new water pump, thermostat and radiator hoses for good measure (and move the trans oil cooler to the passenger side!!). If the situation is still not improved then... high power electric fans?

I won't be able to work on it this weekend, hopefully I'll be able to do the work this labor day or the following work week.

Thank you everyone for guiding me through this!!!!



still need to buy the new radiator hoses, upper and lower

 

To recap:

1. flushed the engine coolant passages with a garden hose
2. installed new radiator - copper core, 2 row, plastic ends
3. installed new thermostat (that I suspect is either junk or is already so gunked up with crud in the cooling system that it's now stuck open)
4. filled up the cooling system with the Prestone flush additive and distilled water. Let it get real hot (too hot at one point) and drove it for a day or two, then drained the radiator and the water was dark brown.
5. new fan clutch (I don't think the old one was the problem though) and 50/50 coolant + water wetter was added to the radiator in place of the brown water that came out
6. still overheats but only after high speed driving for 10-15 minutes. Around town I can drive it all day..
7. block tested the coolant system - results: inconclusive
8. pressure tested the cap and coolant system - results: nothing wrong

 

I would suspect your water pump impeller is eroded but you won't know without taking it off.

 

I feel your pain. I've been chasing a stubborn misfire on mine since Christmas. Nothing I've tried works.

Please be sure to come back and post the solution or resolution once you figure it out. When someone else with the same symptoms finds this thread a year from now, how you end up solving the issue might help them. In my own case, I've read at least a dozen threads with similar symptoms to mine that just dead end without ever telling me whether the guy fixed it, had someone else fix it, sent it to the junk yard or just left it sitting in the yard to rot.