If you use vise grips or such to clamp the hoses you can minimize the buubles you add. I saw a post somewhere about a guy who reversed the heater hoses to force out a bubble. The WP could just "move" a bubble from one place to another.

I have suspected that air bubbles could rise in the system, to the to "attic" space of the intake manifold. That would be above the thermostat slightly. But the coolant sensors on mine actually penetrate the roof of the intake, so perhaps when cold removing a sensor would provide a way to vent. Maybe stick a wet/dry shop vac on it and pour more coolant in while sucking out the air bubble.

Perhaps parts list for HG jobs should include the chemical test for exhaust gas, so proof of performance testing can be done.

 

Somewhere there is plumber with a Disco who has installed a "T" in the heater hose, with a couple of valves and short length of pipe to trap bubbles, and be able to purge them.. Kind of like the pipe stub at the end of a line to prevent a "water hammer" at the sink or bath tub.

Savannah, I believe you may be onto something there. You could rig a T right there with a Flushing Valve with a hose attached that could be used to drain and flush with and a one way bleed valve to allow bubbles to escape.

 

New nickname for the beast...'Rock Steady'.

I thought I would try another 'free' fix and decided to reverse the heater hoses and see what happened per SB's post. I also tried something different on the burping sequence. I warmed the engine at 1250 RPM until the t-stat was opening and everything was nice and warm. I had the heater temp on cold and verified the heater control valve was closed. Then I cranked both sides to full hot. I had both rad caps off too. Well that seemed to do it. I don't know which did the trick or if it was a combination of both but it's back to 8:30 on the gauge and it doesn't move. I drove into town and back twice with no variations. Gurgling noise is gone now to. She was working a bit tonight as we have quite a bit of snow on the ground so it was a lot of snow-running on the roads.

Even with my street-biased tires I'm still impressed with the traction and handling of the LR in the snow. The extra-weight and relatively low horsepower make it very stable in the snow. I just miss my improptu drifting sessions now having AWD. ;-)

Can anyone think of a reason to reverse the hoses again now that everything seems to be working so well? The last thing I need to do is introduce air back into the system.

 

Well, with the flux capacitor reversed, you could create more cold and reverse global warming, covering the "Al Gore Built My Website" bumper sticker with two inches of radial ice... nahh. The later D1s don't even have that valve, coolant flow is all the time when engine on.

Some say that running it reversed will actually make the scale buildup come off over a period of time and improve the heater. Of course if the core is ever toast, you might investigate a heater they make for pick up campers that plumbs into the water lines. Removing dash and you find out the whole truck is built around the core. Must be where Royalty hides the crown jewels...

BTW - is this the 180 or the 195 stat?

 

Hmmm, I hadn't considered the global impact this might have...

Still have the 180 for now but the 192 will go in with the new hoses. Yeah, removing the dash is not very high on my 'fun' meter.

 

Please define reverse, did you swap hose posistions entirely?
Or just switched 1 end of each, reversing the flow thru the radiator?

Mine has the bubbling sound also, and overheated.
PLEASE, I so hope it's not the problem of which we do not speak.

 

Reverse the positions at the firewall, so coolant flows in opposite direction, which will clear out some scale and sometimes a stubborn bubble.

Bubbling and overheat is not a good sign. D2 more pesky to burp air from. By overheat, do you mean that the high temperature light went on and gauge when way above 9:00 position?

Bubbles are air or exhaust gas in coolant. $50 test for that before you start throwing other parts at it, if burping won't clear the noise under dash.

Usuall suspects for over heat:

low coolant / coolant loss from leaks (hoses, radiator, gaskets)

Radiator clogged inside

Radiator fins clogged outside

Radiator fan on reverse direction. Serpantine belt route wrong.

Fan clutch bad.

Water pump bad.

Thermostat bad.

Cracked block, cracked head, head gaskets.

 

You had air trapped in the heater core, reversing the flow cleared the restriction. Having the serpentine belt routed wrong will cause the same type of issue.

 

OK, cool. I see now.
I do need to check that belt first, that may be the cause of my issue, maybe the power steering and/or water pump was/is run in reverse.

I got a lil under 2 hours of mostly highway time on right now, just driving it home from the car dealership. I checked the temp gauge like an addict all the way till I was near home. It stayed dead center of the acceptable range. Then it cut off at the light right off the highway, took a few tries to get it going, I saw some light smoke from exhaust after this, so it may have overheated right at the end of the trip and I did not notice. I never saw the red light, but the wife beared the cold and went back out and said it was lit.

I hope for the best, Best being under $1k fix.

 

A cut off when engine heats up to normal temp, followed by won't crank back up until cools somewhat, is a common indicator of the failing crank position sensor. That can be diagnosed by pouring water on the sensor (driver side rear of engine) to cool it off, or ataching a spare spark plug to a wire you pull off, lay on manifold (don't have SWMBO hold the plug), and watch for sparks when cranked. No sparks is high indicator of carnk sensor issues.

But just general overheat is usually low coolant, and do it enough and you'll have head gaskets or worse a slipped sleeve. Above 9:00 on the gauge is time to investigate. This is not Detroit iron where you can run "very warm"....

As to dealer sold it that way, my D1 came with incorrect belt route, electric fans replaced with used ones and wired backwards, sticking thermostat, radiator plugged with gunk, radiator fins blocked with leaves and mud, and dead fan clutch, wobbly water pump. So replaced fan clutch, radiator flushed and rodded out by an indy shop, new thermostat, replaced water pump.

In other words, welcome to the weekend and evenings Disco repair society...