Cylinder Head Plug
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 7,411
Likes: 253
From: Little Elm TX
Cylinder Head Plug
Ran into my first problem with my new cylinder heads today. There's a plug in the passengers side where my cylinder head temp sensor goes! 
It's a square head and I have no clue as to what size it might be and I don't have any square head tools. Any help with the size would be GREATLY appreciated. I don't want to be buying tools trail and error. 
I was hoping it would be 3/8 like a socket wrench adaptor, but it doesn't appear to be and 1/4 is to small.
It's a square head and I have no clue as to what size it might be and I don't have any square head tools. Any help with the size would be GREATLY appreciated. I don't want to be buying tools trail and error. I was hoping it would be 3/8 like a socket wrench adaptor, but it doesn't appear to be and 1/4 is to small.
Last edited by R23HTC; Aug 11, 2005 at 11:49 AM.
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 7,411
Likes: 253
From: Little Elm TX
Well I figured out part of the problem. The drivers side is missing a plug. Boy I'm glad I caught that before I start dumping anti-freeze. Now all I have to figure out is the size of that square? I think I'm going crazy! 
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
You are correct on the size, I didn't want to mess around looking for something I could use so I took my small propane bottle torch and heated the area around the plug and then put a pair of vise grips on the plug and it came out easily. Didn't even scratch the head.
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Burning Brakes
Joined: Aug 2004
Posts: 1,110
Likes: 1
From: Geneseo Illinois
St. Jude Donor '06
i think i ran into exactly the same problem. A friend of mine, a mechanic, came over, looked at it, went back to his garage and a little later came back with a 5/16 square headed tool. I think he had ground down a 3/8 " to fit. came out like a charm.
Pro
Joined: Apr 2005
Posts: 590
Likes: 0
From: Boynton Beach, FL
Same Problem
I just ran into the same problem on the 93 I bought. I tried to remove the driver side plug to put in a fan temperature switch. I bought 5/16" hardened keyway stock, cut off an inch and inserted it into a 5/16" ratchet. The heads are still on the car. The plug was in so tight it would not come out even with a 1/2" breaker bar. It rounded the corners on the hardedned keyway and the plug square is now a parallelogram. I wound up buying a temperature switch you plug into the radiator hose. I hope you have better luck. 
Larry
Larry
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 7,411
Likes: 253
From: Little Elm TX
Originally Posted by Vetracr
I just ran into the same problem on the 93 I bought. I tried to remove the driver side plug to put in a fan temperature switch. I bought 5/16" hardened keyway stock, cut off an inch and inserted it into a 5/16" ratchet. The heads are still on the car. The plug was in so tight it would not come out even with a 1/2" breaker bar. It rounded the corners on the hardedned keyway and the plug square is now a parallelogram. I wound up buying a temperature switch you plug into the radiator hose. I hope you have better luck.
Larry
Larry
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 7,411
Likes: 253
From: Little Elm TX
Originally Posted by GS345
I had the same problem on my GS. I looked through my tool box and found a square shank screwdriver, cut off the end. Worked wonderfully
jeff
jeff
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 7,411
Likes: 253
From: Little Elm TX
Originally Posted by ittlfly
You didn't say if the heads are on the engine. If not, run it down to a machine shop. It probably take longer to drive there than take the friggen plug out. 
That's when I found out it's a good thing I noticed as there was no plug on the drivers side. Sure would have been a big surprise to watch all my new coolant come pouring out. 
Safety Car
Joined: Apr 2003
Posts: 3,793
Likes: 9
From: VA
It's a pipe plug, and what you need is a pipe plug socket.
Such as:
http://buy1.snapon.com/catalog/item....8&group_ID=259
I'd expect NAPA to carry something like this.
Such as:
http://buy1.snapon.com/catalog/item....8&group_ID=259
I'd expect NAPA to carry something like this.
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
Originally Posted by R94 LT 1
Yeah they are on. If they weren't I'm sure I could figure it out. I put them on, got them all torqued down, the intakes on, and I'm putting all the sensors back in and I'm like WTH! That's when I found out it's a good thing I noticed as there was no plug on the drivers side. Sure would have been a big surprise to watch all my new coolant come pouring out.
That's when I found out it's a good thing I noticed as there was no plug on the drivers side. Sure would have been a big surprise to watch all my new coolant come pouring out.
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 7,411
Likes: 253
From: Little Elm TX
Originally Posted by steve9899
It's a pipe plug, and what you need is a pipe plug socket.
Such as:
http://buy1.snapon.com/catalog/item....8&group_ID=259
I'd expect NAPA to carry something like this.
Such as:
http://buy1.snapon.com/catalog/item....8&group_ID=259
I'd expect NAPA to carry something like this.
And yeah, that Snap-On tool is what I need.
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 7,411
Likes: 253
From: Little Elm TX
Originally Posted by STL94LT1
Same thing happened when I changed heads. I just wired/installed the temp sensor on the driver's side.