I changed my knock sensor today. And as I was removing the old one I expected a flood of coolant, but when it finally came out not a single drop of coolant spilled. Isn't this a coolant drain plug? I didn't pre-drain any from the radiator. It should have been a full system. Afterwards I check the overfill bottle and it showed full.

 

There's gotta be coolant coming out of it for sure. I've changed about 4 knock sensors and every single time there was plenty of coolant coming out.

 

Nope not a drop. The car was ful of coolant in the overflow bottle. I couldn't check the radiator since I took it on a test drive first. The car has been running like a champ with the temp just a tad over the first black line. I don't understand this.

 

i'd be VERY VERY concecerned

 

I am going to TTT this for a few more replies before I let it die.

Tthe car is running fine and not hot so coolant is obviously flowing. I flushed the block last time I had it tore down for the opti replacement a few months ago, and everything came out clean and clear. Could it have been the angle the car was on? I only had that side jacked up while I was changing the sensor?

 

Should have been some coolant come out unless there was some sludge at the hole stopping it.

 

Ok, In your extremly valued opinion. Since the engine seems to be running fine and not hot, should I do something or leave it be and not worry until it blows up.

 

I'd flush it again for sure. Unless your car was sitting at a 90 degree angle (and if so, I'd like to see a picture of that ), coolant should come out.

Usually comes out on your head, while you get all pissed off that it is splattering everywhere and that slimy, sticky, nasty coolant is all over you, down your back, and smells terriable. Then when you think it is all out, that one last splatter goes right in your eye, because that is only fair. Then once you dry yourself off, you bump something and it goes all down your back again. But I'm not bitter or anything.

 

If it is indeed sludge that is keeping it from coming out, a flush would certainly be good preventative maintenance. IMO, it would indicate the system needs attention. Then again, the lack of coolant coming out could be caused by casting flash or something. You might want to remove the sensor again and poke up in the hole to see what is really going on. Then you might be able to enjoy all those things that Joe experienced.