Any Idea what this Is?

TRISCUIT

MEMBER
1986 TOYOTA PICKUP
2.4L
4 CYL
2WD
AUTOMATIC
130,000 MILES

Hi,

I’m slowly taking apart things to remove my cylinder head for a head gasket R&R, and after removing my top radiator hose, I decided to empty the little bit of remaining coolant into a bottle. After doing that I turned the hope vertically and this little pin(?) Fell out.

What the heck is this thing? I set a key next to it for size reference.

I have no idea what it is. I haven’t removed the intake side fully, or the thermostat housing (yet). I’m glad I followed the urge to watch what came out of the upper hose otherwise I would have never noticed this thing.

Picture below.

Thanks for any advice/help/guesses.

Image (Click to make bigger)

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

I've been in the business for nearly 40 years and have never seen something like that in the cooling system. Is it a solid piece of metal? There is a chance it was dropped into the radiator by accident at one point. There isn't anything in the "cooling system" that would look like that.

As far as the head gasket, I attached the directions below (in the event you need them). Make sure to remove the head bolts in the order indicated and reinstall them using the process indicated.

Let me know if this helps or if you have other questions.

Take care,

joe

See pics below. The last pic provides torque specifications and sequence.

Images (Click to make bigger)

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Thursday, January 11th, 2024 AT 8:32 PM

TRISCUIT

MEMBER
76 POSTS

It’s odd, isn’t it? Yes, it is a solid piece of metal that is cylindrical in shape and clearly was machined for a purpose. It didn’t shear off of anything.

My first thought was, “Did the thermostat come apart?” But that piece doesn’t look like it came off of a t-stat, even if mine did break apart somehow. I’ll know more when I remove the housing.

Then I thought, “Did something break off in the radiator?” I may remove the lower hose and see if anything comes out of that one (aside from coolant).

Thank you for the cylinder head removal instructions. Is it safe/reliable to bench test the thermostat with boiling water when I get it out to ensure it doesn’t need to be replaced? It’s new but the truck never came up to operating temperature either before or after its replacement. The truck has been sitting for a while so I’d like to test the t-stat while I’ve got everything apart.

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Monday, January 15th, 2024 AT 2:39 PM

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

It is a good idea to test the thermostat. I've been seeing a lot of faulty new parts. Keep in mind, the thermostat should be fully open at 195F.

Let me know if you have questions or if I can help in any way.

Take care,

Joe

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Monday, January 15th, 2024 AT 7:21 PM