Final report on this one:

Replaced the water pump and fan clutch. After chasing a few stupid leaks with a pressure tester - mostly hose clamps giving out- it was holding steady at 20 psi.

Bled it, Started it and the darn red light stayed on. I turned it off and grabbed the phone obd Bluetooth adapter- I could get a coolant temp from there even when the guage was dead. Drove around, and everything worked good, temps were great, and after a few minutes the guage came back- must have been an air bubble.

I do hear the waterfall, so I'll be bleeding it over and over in the next week, but I am officially done and successful! Thanks to all for your help!

-rj

 

make sure you bleed it stone cold and do not be afraid of loosing coolant, the air is not just sitting at the tee waiting to be let out.

 

What are your operating temps when engine is warmed? @ idle before truck is ever moved, city/town, highway, and then normal driving AFTER highway. This is where some of us get a good spike. Example is 194 on highway, exit then stopped at a couple of traffic lights and temps go from 194 to 200-205 in just a few seconds. Air will make it worse. Do the normal "remove tank from holder, lift and add water til it flows freely" out of purging valve where that screw has been removed also. Put screw in, snap tank back, put cap on start truck with heater on high fan mode with heat @ 84. After 2 mins crack the bleed valve on top hose enough for water and air to fizz out for 30 seconds. Tighten up, build pressure again for 2 minutes and loosen it again til air fizzes. Repeat several times and see if it helps. Keep the OBD scanner plugged in and watch temp like a hawk. Sorry for the redundancy of stating the whole procedure you have done numerous times. I just wanted to be specific as this has worked for me. Good luck, buddy! There are many ways to purge air but you may give this a try, if you haven't already.

 

Well if you take off the coolant cap slowly when it is hot.
and then rev it to 2,000 RPM and hold it there.
And if coolant blows out the coolant tank with the cap off - you
probably got pressure in the coolant from a head gasket leak.

125K is prime head gasket time.

But
If you not getting mis fire codes due to coolant in the cylinders in the morning then that is a good sign that things are ok.

yeah you gotta make sure all the leaks are gone.

Put card board under the rover at night and check the cardboard for coolant.

 

Augh! It's not over, apparently. To review, at this point I have replaced the water pump, viscous fan clutch (HD replacement), and pressure cap. New coolant with water watter, and everything was flushed when I had it appart. No sediment or anything nasty came out or evidenced under water pump. Radiator seemed to flow with no resistant with the garden hose.

I have not been able to get rid of the waterfall. After the initial run with the OBD temp data, I was spoilked and got a OBD temp guage (HUD version, pretty fantastic). I went on my first long trip yesterday and things were not awesome.

It was a 60 degree day on the interstate going 65 MPH. From a cold start, it would go up to ~225, then drop (Thermostat opening). On the whole, it would cruise at 199, but after a random period of time, it would start climbing quickly. dropping speed would usually bring it down somewhat to the 210, but there would be a point where I coulsnt stop the inevitable. I would pull over (thankfully, before it got too high), let it cool for 10 minutes, factory bleed it. Unless the coolant was bubbling out, it didn't really take any fluid. From a restart, it could last anywhere from an hour to 10 minutes. Twice, the temp was steady but higher (205), and once it stayed ~190 for almost an hour. Weirdly inconsistent.

One thing I notices is that the coolant tank is always super full. I bleed it and leave the proper amount of coolant in (about 2/3) but when I stop and it's hot it is as full as can be. I bleed it and get air out, but it's basically the water in the tank and I don't have to add more. I have been and bleed it extra, but I'm really not loosing water.

Today I bought a hose barb fitting from the hardware store and I have 4 feet of high temp clear diesel fuel line going from the bleeder to the elevated coolant tank. I start the car, and it swirts out into the coolant tank and I get a fair bit of bubbles - I figured after 5 minutes it would be done, but I never seem to stop getting bubbles completely. It will be good for 30 seconds, then a another clump comes out. The heater is on full while this is happening. Is this a valid process?



I'm running out of options- my thoughts:

Coolant does run out when I open the overflow when it's running, and it seems to fill itself. Could there be resisitance in the radiator thats causing backpressure?

Water fall noise seems to come and go, as does effective heat from the vents. Could I have a massive air bubble/ airlock thing going on?

-rj

 

Have you tested the coolant for exhaust gasses? Sounds like gas is getting in.

 

I guess I need to do that.

Been observing another interesting fact: when idling, coolant flows out consistently. When you give it some throttle, the stream will get stronger, it will get bubbles, and occasionally it will stop altogether, tube will go empty, then it will slowly and chaotically restart- just like the water pump is losing its prime. Any vacuum leak on the pump side would still be under pressure, especially when I shut it off, right?

-rj

 

Being able to easily open reservoir cap after just a ten minute cool down without loosing much coolant would lead me to believe system pressure is low and suspect a bad cap.
......

 

I should have been more exact- after letting it cool for ~ 10, I crack the bleeder until is stops hissing. Only then do I open the resolvoir. Otherwise I would loose lots of coolant.

So your resolvoir is pressurized when warm also? That's a comfort.. It's a new cap, but new parts can be bad-

No engine codes and it sounds and runs lovely- really hope it's not s head gasket. Has test kit is on its way to make sure-

Other theories: new thermostat is bad, and keeps sticking.

New water pump is bad and is sucking air for some reason.


Can anyone disprove any of the theories on the board right now ?

 

Sounds like your bleeding it hot?
The rave says cold iirc.
and yes a co2 of the coolant would head off a lot of fears..