Help - Please ID this item

[Schmieder]

1996 Grand Prix SE 3100

Special bolt like item on the cylinder head. Only one per head and has a square female adapter for insert/removal.

Picture_of_item

I need to purchase these items but I haven't a clue what they are called or the dimensions they are. The pic is my old cylinder head. The new heads do not have them installed. I tried to remove it but it is not budging. It bent some really tough steel trying to remove it. They are in there too darn good to remove. I don't even think a blow torch will help.

Please help me ID these things so I can get a pair and move foward with my turbo build project.

Thanks guys!

[Weatheralls Auto]

Goes into coolant passage for a Temp sensor.
what you are pointing to is just a plug.
(only 1 head would get the sensor which would be a single wire for the dash unit)

Using heat will help remove them for sure, they are in with pipe sealant (not JB Weld, as pipe sealant seals pretty darn good as you can now see lol)

[86FieroSEv6]

...also used for coolant fan switch on some applications. Pipe plugs should be available at your local hardware store.

[Superdave]

It's a metric threaded plug if i remember right.


I'd try heating it up to remove it, if that doesn't work i'd just pick up an extra single wire CTS and thread it in there. lol

[Schmieder]

It's a metric threaded plug if i remember right.


I'd try heating it up to remove it, if that doesn't work i'd just pick up an extra single wire CTS and thread it in there. lol

I have an old CTS around here somewhere.

And in fact, I keep old stuff like that. I replaced it and stuck the old one in the box to save.

In fact.......my wife said, "Why are you keeping old stuff you'll never use?" I told her you never know.

So now, I have an old CTS I can use to match the thread ..BOOYAH!!! She's going to just love this 'I Told Ya So"....lol


I think I'm going to thread in a CTS for the rear head (Cylinder #5), so later I can rig a sensor when I need to read the temp in that area.


Once again, 60degreev6 to the rescue. I love you guys, the number of headaches avoided is substantial. It's like this web site is a pain reliever for 60degree enthusiasts.

Updated Post: I know the system is calibrated to read water temps from the block next to the thermostat housing, but with a little tuning wouldn't it be a better spot to read maximum water temps in the coolant system? Ehh, I think I just get a water temp gauge later and run it into that passage. Seems if one were to ever get a head gasket leak, that sensor would read high temps first due to the exhaust gasses entering the coolant system. Seems like a good safety system when running boost, even just for cylinder head temps since boost is going to increase temps anyways.

[Schmieder]

Goes into coolant passage for a Temp sensor.
what you are pointing to is just a plug.
(only 1 head would get the sensor which would be a single wire for the dash unit)

Using heat will help remove them for sure, they are in with pipe sealant (not JB Weld, as pipe sealant seals pretty darn good as you can now see lol)

It bent hardened steel. Last night I thought about cutting them out. That would be a load of laughs for the guys who get the heads for my core charges, lol.

I may actually try a blow tourch. Since the heads are aluminum and the plugs are probably steel, the aluminum will expand faster releasing pressure. That is probably why they are in so darn tight from years of heat cycles, aside from the teflon tape.

[IsaacHayes]

I thought 96 3100 had a 3 wire CTS in the thermostat housing? Yours has a 2 wire in the theromstat housing for the PCM and a 1 wire in the head for the gauges ???

Get a 3 wire CTS from a Beretta and swap it in if you want to read the same spot as the PCM does. I did that on my 94 3100 just because the sensor in the rear head was bad, and I didn't feel like spending money to replace it, or get to it as the thermostat neck was easier to get to and I had a spare sensor.. hehehe

I'm not sure a CTS to plug it on the other head will work, won't that run into the timing chain cover/water pump housing?