Knock sensor lead

[shaker3940]

Hi all, I want to give my VX V6 a coolant change and as per the gregorys manual it says I have to remove the Knock sensors to completely drain the block of old coolant. I have found the sensors but for the life of me I cannot figure out how you get the wire off (I didn't try to hard for fear of breaking the wire) can anybody out there advise me on how the wire unplugs from the sensor?

[vt_lover]

you need to pinch the plug with your thumb and forefinger.

[shaker3940]

So you would need to remove the heat shield so you could get a grip on it?

[Peter X]

Well Well i removed my knock sensors on the weekend - broke one i wont do it again - no need - i read the book as well - when i took the sensors off there was no bloody coolant behind them - I turned in car heater to on - took radiator cap of bottom hose off drained all coolant - top radiator hose off - put garden hose in top radiator hose stuffed rags around it and turned tap on ran water through for about 5 minutes till water was clear - i kept thinking about the knock sensors so i took them off no bloody water - but if u wantn them off (holden service techs don't take them off when they flush)
The passanger side one is the easiest - it is oval shaped use your fingers squeeze the the widest part of plastic n pull plastic off then use a socket to remove sensor - the driver side is harder - n stupid me used pliers this one i broke - Remove the heat sheild n u should not have a problem

[avanti_rider]

I agree with Peter X. I did exactly the same thing when i flushed my coolant about a month ago. Dicked around for ages trying to get the knock sensors out and ended up breaking one of the wires. When i finally got the knock sensors out, no more coolant came out! I ended up using the hose to flush out the block and radiator and it got a heap of crap out.

[Kunu]

best thing to use to get these off (only when replacing them) is to use a pair of extra long 45 degree nose pliers check picture below..and u will have no dramas in the future..beats me why they say to remove them when changing coolant as none is present grrrr

[graham7773]

It is a good idea to flush the cooling system with Nulon R40 engine flush before you do anything else. When you took the knock sensors out, did you push something thin into the holes to clear crud build up? If not, you still have crud in the block which will eventually cause problems with coolant flow. If the holes are cleared, you will get another 6 liters of old coolant out. By the way, when you put the new coolant in, do not premix it. put 6 liters unmixed in and top up with your choice of Distilled or Demineralised water.