This is a slight tangent to my 'overheating' thread.

Basically, I bleed and bleed, and still get air. I've bled it the proper Rave way 15 times and about every other way i can find, and still get air. I got a fitting and some tubing and ran the tubing into the elevated resouvior. Bleed it cold (proper-style) then started it and watched the fluid go through the tube. Still get air. Eventually coolant will come out of the overflow under pressure.

I checked the obvious suspects: new pressure cap, new fan, new water pump, new thermostat. I've tested for exhaust gases over and over again, nothing (thank goodness). I flushed whole system last week with water pump. I didnt see anything nasty and radiator seemed to flow okay. Pressure tests were fine. no leaks, no lost coolant.

Where can this air be coming from??? It's getting in there from somewhere-

Extra info, may not be useful: When accelerating, lots more bubbles come out of tube. Tube 13 in digram (connecting tube) is always empty. Bottom tube is usually much cooler than top in radiator, and 80% of radiator is confortable to touch but top part is certainly not.

Any ideas where air can get in but coolant can't escape?

-rj

 

Check this thread. Bubbles in the system was mentioned, this might help.
https://landroverforums.com/forum/di...time-d2-77961/

 

One month later update/conclusion:

Along with the perpetual pressurized overflow and random overheating, I started hearing what sounded like an exhaust leak from the passenger side that just got louder. I threw up my hands and tore it down to the shortblock, had the heads tested/refreshed, and put it all back together.

The gasket was dissolved between 4 & 6, which answered the exhaust leak sound. There was some gasket corrosion between the cylinder and water path on 7, so I have crossed my fingers and prayed that was the source of the exhaust gas in the coolant.

In the end, despite all the Co2 testing, I think the only possible answer was that there was exhaust gas in coolant. I was very atypical - no coolant loss except when the overflow happened, and a negative reading on the Co2 test. No oil in water or water in oil. Weird.

I have also done the thermostat mod (live in west central florida - so no worries with cold) , and my temps are around 188. Still seems a bit high, and it fluctuates quite a lot (87,93,98,92,87 over 2 minutes coming to stop after steady driving), but the pressure isn't happening and all in all things are great. I'm going to assume this saga is over.

Thanks for all of your help!