Hi all.
I know I wrote a few weeks ago that I had winterized my late model A4 ("Thermostat winterizing question", this topic), but something was nagging at me and I had to get to the bottom of it. The something was this:
The block drain located behind the starter and alternator did not drain anything after the fresh water flush and before adding antifreeze. I inserted a wire to clear debris that might have been blocking the drain with no change in result. When I added antifreeze, I assumed, always a bad thing to do, that the antifreeze would push out any remaining fresh water. But, as time passed, I realized that I was not confident in that assumption.
I then determined to remove the thermostat to see, first, if I even had one, and then to see the content of any fluid I might find in the block. Removing the thermostat housing was an adventure; I achieved success today. (I have one dirty thermostat!) Indeed, the block was full of fluid, but upon observation it was clear that it was a mixture of antifreeze and water. Therefore, the block must be drained and new antifreeze installed.
But how can I do this if the drain is not functioning properly? The Manual says there is a second drain, shown in the panoramic view to be under the water pump, but I can't find it. Even if I could, it is probably blocked as well. I can pump the block through the thermostat aperture or drain it out the by-pass hose, but I'm not sure that would drain the entire block. Even if it did, I need to open up the drains provided for the purpose.
So:
How can I unblock the drain I can find?
Is it possible I don't have a second drain under the water pump?
Is draining the block through the by-pass and installing -100 antifreeze sufficient?
On a less important note, I may have stripped the threads on the studs to which the thermostat housing is bolted. How are they best removed in the event I need to replace them?
Thanks for all assistance.
Mark
I know I wrote a few weeks ago that I had winterized my late model A4 ("Thermostat winterizing question", this topic), but something was nagging at me and I had to get to the bottom of it. The something was this:
The block drain located behind the starter and alternator did not drain anything after the fresh water flush and before adding antifreeze. I inserted a wire to clear debris that might have been blocking the drain with no change in result. When I added antifreeze, I assumed, always a bad thing to do, that the antifreeze would push out any remaining fresh water. But, as time passed, I realized that I was not confident in that assumption.
I then determined to remove the thermostat to see, first, if I even had one, and then to see the content of any fluid I might find in the block. Removing the thermostat housing was an adventure; I achieved success today. (I have one dirty thermostat!) Indeed, the block was full of fluid, but upon observation it was clear that it was a mixture of antifreeze and water. Therefore, the block must be drained and new antifreeze installed.
But how can I do this if the drain is not functioning properly? The Manual says there is a second drain, shown in the panoramic view to be under the water pump, but I can't find it. Even if I could, it is probably blocked as well. I can pump the block through the thermostat aperture or drain it out the by-pass hose, but I'm not sure that would drain the entire block. Even if it did, I need to open up the drains provided for the purpose.
So:
How can I unblock the drain I can find?
Is it possible I don't have a second drain under the water pump?
Is draining the block through the by-pass and installing -100 antifreeze sufficient?
On a less important note, I may have stripped the threads on the studs to which the thermostat housing is bolted. How are they best removed in the event I need to replace them?
Thanks for all assistance.
Mark
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