My coolant temp sensor on my drivers side head is loose in the head and leaking coolant fast. Do I just replace the whole piece into the head?

Thanks for any help guys

 

I'm just going to keep posting as I try things, anyone feel free to chime in.

So I've never seen a mechanical sensor before and that must be one.

I checked the head casting numbers and turns out this engine was an efi 350 originally.

The sensor I got today was period correct 350 small block but is electrical and the sensor element itself was much shorter.

I'm assuming that is an adaptor into the head to run this "incorrect" sensor. The adaptor is loose in the head making me worried that the threads may be stripped.

What should I do? New heads if it's stripped?

 

That is for an aftermarket gauge, not stock at all.

"EFI" doesn't particularly matter in this case.

About all you can do, is either figure out what brand and model and whatnot it is, and replace that; or, find the stock wire, put the stock sending unit back in, and hook the stock gauge back up.

 

You could replace it with one of these. They use the same type of sender

http://www.summitracing.com/parts/rnb-7-120

 

Try inserting either the adapter you have, or the new one in separately (smallest single piece) to make sure the threads in the head aren't stripped. After you verify it's not stripped, you can use some teflon tape to make up some of the difference if it is a loose fit, or leaks. I'm not sure why it has an adapter like that, maybe to keep it away from the headers?

 

The reason is because it has a longer probe like this one. He probably could not seat it otherwise.

 

I would try to actually put the sensor part in the head instead of the 90*, extension and bushing combo going on there. It will give a more accurate reading. Especially with it turned up like that, air bubbles can settle in there with no way to bleed out except the leak you have. Someone went through a lot of trouble to put that in wrong...hacking the header flange?

 

Ok, thanks for the info on the length of the sensor.
Edited: I agree on it not reading accurately with the 90° adapter as well.

 

I run the factory gauge off the head and the same mechanical gauge I posted in my intake manifold. The gauge reads the same as my IR temp gun.

 

Sorry, I wrote that wrong. I meant with the 90° extension/adapter. I'm using a mechanical gauge myself.

 

I bought the factory sensor and put it directly into the head. Just need an electric gauge now! That was a lot of good info, thanks guys! Now for my throttle hesitation...