You can use an exhaust sniffer (or your local mechanic can) to detect the
presence of exhaust gasses in your coolant tanks.  If so, almost certainly a
cracked head.

Karl Wolz
 
 

|-----Original Message-----
|From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] 
|On Behalf Of Evan Mac Donald
|Sent: Monday, November 28, 2011 8:22 PM
|To: vanagon@GERRY.VANAGON.COM
|Subject: <No Subject>
|
|Ok list, I need some help.
|
|I need somebody to tell me the symptoms my poor '85 1.9 WBXer 
|is�suffering from are not from a cracked head. Lie to me if you must.
|
|So, to explain. My van (Butternut) has always self-bled her 
|cooling system�very quickly, and easily. No fights, no real 
|fussing, just a couple of top-offs after a couple of careful 
|hot-and-cold cycles, and Viola! Done. This is from several 
|waterpumps, hose replacements, damage repairs, etc. Always 
|bleeds fast, after the damage is gone.
|
|The last run we made in beasty was at the end of September, to 
|Busses by the Beach Bus Boo, in western Michigan. Lots o' fun. 
|I live in eastern Michigan, so the trip is only about 180 
|miles. No big deal. Done the trip LOTS of times, and in much 
|worse weather.
|
|This time, about 5 miles from being home, the heater stops 
|working, and the temp gage maxes out. Quickly. And the coolant 
|level light blinks. The weather at the time was about mid 
|50's, in �F. UH-oh. not good. I stop, and the light stops 
|blinking, and the gage returns to normal. Huh? Check the 
|tanks, and both are full of air. Now, my reservoir tank never 
|has bubbles, after bleeding. So , I fill the tanks, and start 
|home again. Cycle repeats. First I have heat, then none, and 
|the gage does its dance. It is the old style gage, that maxes 
|out the temp needle, if the low-level alert light comes on.
|
|I have tried several times, over the intervening time, to get 
|the bubbles to go away, and my heat to return. I completely 
|emptied and refilled the entire system, with a pressure flush 
|in between. I even unhooked the belt from the water pump, and 
|spun it with an angle grinder, to get things moving around, 
|without actually running the engine, and risking further 
|damage. This will really only clear the heater cicuit, but 
|that is a big section of the problem, all on its own. No joy. 
|
|
|My thought is that I have cracked a head, into a coolant 
|passage. I do not want to do a head if that's not whats wrong, 
|but I do not see any other solutions for this problem.
|
|My question is: are there any other likely causes of this? Or 
|am I going to have to replace a head?
|
|TIA, and I hope everybody is over their tryptophan overdose...
|�Evan Mac Donald 
|
|
|"...in the absence of facts, myth rushes in, the kudzu of history."
|-Stacy Schiff
|-----
|No virus found in this message.
|Checked by AVG - www.avg.com
|Version: 2012.0.1873 / Virus Database: 2101/4645 - Release 
|Date: 11/28/11