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Discussion Starter · #1 ·
I just replaced the radiator in my 96 BBB. After draining the radiator, I noticed that both radiator hoses go to the top of the engine and there is still a bunch of old coolant in the engine. How do I drain all of the coolant that is in the engine? Thanks
Z
 

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I just replaced the radiator in my 96 BBB. After draining the radiator, I noticed that both radiator hoses go to the top of the engine and there is still a bunch of old coolant in the engine. How do I drain all of the coolant that is in the engine? Thanks
Z
To drain the block, you should remove two knock sensors on both sides of the engine. Just squeeze the electrical connectors and pull them off. You need 22mm socket or the closest SAE socket for the knock sensors.
 

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Before pulling the knock sensors I would have a couple of replacements on hand as it is likely one or both will get damaged. On a previous car of mine the knock sensor started turning in the housing which made it quite difficult to remove(the case is just press fitted together). The correct size is a 22mm socket but will deep well socket or maybe a medium well might just fit over the connector. You will have to remove both knock sensors to fully drain the block. - Peter
 

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for 96 block knock sensor part # is 10456287 and tq is 14 ft lbs...don't over tighten and use thread sealer on them
 

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You can probably get most of it out by pulling the temp sensor out of the front of the water pump. But yeah, if you want to pretty much completely drain the engine, knock sensors.
 

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Two other tips:
1. Point the car as downhill as possible
2. Disconnect the steam line hose from the coolant tank and blow compressed air through it. That will force a lot of coolant out the front of the block at whatever opening you choose (temp sensor, lower water pump bolt, etc.).
 

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Two other tips:
1. Point the car as downhill as possible
2. Disconnect the steam line hose from the coolant tank and blow compressed air through it. That will force a lot of coolant out the front of the block at whatever opening you choose (temp sensor, lower water pump bolt, etc.).
Be VERY careful with that tip No. 2. I tried that on our 96 SS. I blew air into the steam line I had disconnected from the reservoir, with the radiator hoses disconnected. The pressure built up. When I stopped, all the pressure blew the coolant back out the steam line. It SUCKED!

Now it may have worked better if I had disconnected the heater hoses, but if you didn't it makes quite the mess.
 

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Discussion Starter · #8 ·
Thanks for the tips guys. Very much appreciated!!! Are knock sensors expensive?
 

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Be VERY careful with that tip No. 2. I tried that on our 96 SS. I blew air into the steam line I had disconnected from the reservoir, with the radiator hoses disconnected. The pressure built up. When I stopped, all the pressure blew the coolant back out the steam line. It SUCKED!

Now it may have worked better if I had disconnected the heater hoses, but if you didn't it makes quite the mess.
Good point. yes I had the heater hoses disconnected at the water pump. Perhaps the trick is to just wait until all of the block pressure has dissipated so nothing comes back at you when you remove the air gun. The other trick is to spray short bursts in a repetitive motion. This gets a wave action going inside the block and helps slosh out more coolant.
 

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Thanks for the tips guys. Very much appreciated!!! Are knock sensors expensive?
A quick lookup revealed about $35 from my local parts store.
 

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Discussion Starter · #13 ·
Thanks Cletus. Therer they were clear as can be. I didn't even break them. What a crappy design though! Thanks again.
 
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