

| Subject: | Over-full overflow tank..cause for alarm? |
| From: | Don Hanson |
| Date: | Mon, 19 Apr 2010 09:18:02 -0700 |
My first 'longer' trip in my 84 (with an inline 4 Golf Jetta motor) since around Xmas. I've been driving it, after letting it stand for a few months, for a month now on shorter trips. Everything seems fine, no poor running or power loss, no strange behavior at all... I may be 'gunshy' now or perhaps overly-concerned for no real reason but when I first got this van, I caused myself some extra work because I was unfamiliar with the WBX cooling system. I didn't get a proper air-bleed after flushing the coolant for new..This resulted in some odd temperature behavior issues that I didn't 'pick up' on until I had damaged my headgasket. I had to replace the headgasket on the I-4 motor, no big deal..about 3-4hrs only, but I could have done BIG harm if I'd ignored it...thanks to the list I caught it in time to avoid major damage..So now I've learned to pay close attention to how my WBX cooling system (the I-4 plugs almost directly into the stock vanagon 'circulatory system') is behaving. Yesterday I did about 250 miles around Mt Hood going to and from a bike race and I noticed my temperature gauge was reading slightly lower than usual. I put a tank of premium fuel into the van and that is what I was burning on this trip, if that would make a difference. My temp gauge usually reads on or just slightly above the second of the bottom two marks...below that LED. Yesterday I was seeing the needle just above the bottom of those two lines, even when climbing to ~5000'...until I got back to low elevation when I noticed it back nearly to where it always has been...Some fluctuations in the reading...Not a fluttering of the needle, the gauge looks to be operating normally...but the needle would move, over a 10-20min period from quite cool to where it normally has run and maybe fall again...So my gauge is showing 'system running very slightly cooler than normal' When I got home I went back and opened the license plate to check my coolant overflow tank level. It was over-full and poured out about a cup of coolant when I removed the cap...So I opened her up to check the pressure tank...No air in there. The coolant looks normal, also..no combustion by products are evident. Water pump feels fine, though I didn't take off the drive belt and spin it...Next, I went to the air bleed screw in the rad. It took about a cup of coolant, added right into the bleed screw hole, as I've devised as 'my' method of getting the last air bubble out of my radiator. So what would cause my coolant to 'migrate' from the pressurized cooling system into that overflow tank? and should I be concerned? It's not running out of the Normal temp range, but pretty close to 'too cool'... any change in operating temp is alarming to me, since when my first problem happened, the symptoms were 'cold air from the heater' and the temp gauge behaving quite erratically... Don Hanson
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