I am adding a mechanical coolant temp gauge to a 1997 LT1. I have good access to the plug that is in the passenger side head. However, it looks like you could stick a 3/8" ratchet in it and crank it out like on a rear end fill plug. That is not the case. The 3/8" ratchet is too big and a 1/4" ratchet is too small.

Is there a socket set I can buy to get this plug out?

Thanks,
Ryan

 

It's a 5/16 square drive.

 

thank you sir.

 

That socket is proving difficult to find...

 

You could try a quality piece of 5/16" square stock in a 5/16, 8 point socket.

 

Just picked some square stock up...I think it is going to work good.

 

It worked out like a champ. Thanks

 

Good post. I just had the same problem.

 

 

so this plug is on the passenger side head, just the opposite of the ect sensor on the driver side head??

What thread and pitch is the adapter needed for this?

 

It's near the rear, since the heads can be used on either side.

3/8-18 pipe thread.

 

yeah, between #6 and #8. I felt down there, but I didn't feel any plug. I did feel a "hole" w/ possible threads, but it was nowhere near as big as the one on the driver side.

What gives? I definitely didn't feel a square plug.

 

SHBOX can you tell me which Autometer adapter I need so I can hook up my sensor to the passenger cylinder head.

Autometer atm-2263

atm-2271

atm-2370