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I took off the valve cover to adjust the valves on my TR3 and found a small puddle of green antfreeze on the 'slotted 50 cent sized" plug which I am assuming is a frost plug of some sort? Dosnt't appear to be any antifreeeze in the oil as there is not the usual 'chocolate milk" mixture you see with a blown headgasket. Is it possible that this plug is just seeping antfreeze? Is this an aluminum plug I have heard being mentioned. Should I replace it? How difficult is this to do. Any advice appreciated. PS The car has sat all winter except for a 15 mile drive about a month ago.
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OhNo! Small amount of Afreeze under Valve Cover?
- Thread starter karls59tr
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TR3driver
Great Pumpkin - R.I.P
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The original plug was cast in place, and it's not unusual for them to corrode from the inside out. I would replace it sooner, rather than later.
With some care, I think you could do it with the head still installed. Take the rocker shaft off and put plenty of clean shop rags around the area, to keep any shavings from finding their way into the crankcase. Then afterwards, flush the cooling system to carry away the shavings that fell down inside the head.
The original plug is not very thick for it's diameter, so you want a hole small enough that the pipe plug just barely starts into it rather than being seated full depth (and possibly impeding the flow of water). I don't remember offhand if there are any internal partitions in the way, but if so you may need to modify your tap a bit.
I'd probably use a little Loctite 565 too, although I didn't know about it last time.
I just looked at my spare cylinder head and it has an aluminum plug in it that is stamped SS in large letters and "Stan 403" in small type in a circle. This is most likely the stock plug. The plug in the head with the leak has no markings,dosn't look aluminumn and has a slot in it, so I assume that the original has been replaced with the NPT threaded plug mentioned. I'm thinking that I should be able to carefully drive out the plug using a drift and a ball peen hammer? I see that Moss has the correct plug for $13.00. I wonder if there is any difference in the one they sell as compared to an NPT you can buy at plumbing supply? Would it be advantageous to coat the threads with some sort of sealant?
The plug does corrode from the inside as Randall mentioned. When I rebuilt my engine I hit the plug with an icepick and it went right thru. The replacement part has been back ordered for over a year. I'm getting tired of waiting for the part so I will replace with the type plug mentioned above. It sounds like the plug you have is some sort of replacement. Permatex has a high temp thread sealant that I plan to use on mine.
The plug came out easily.It was made of aluminumn and threaded so the original was likely replaced when i got the head done.(I think the original plugs get boiled out when the head is hot tanked for cleaning?) I would like to reuse this plug with the proper sealant. High temp Permatex was suggested. I'm thinking since aluminumn and cast iron have different rates of expansion.....is there a more suitable sealer or is the Permatex the way to go?
g1enterprises
Freshman Member
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That special tool you made was pretty crafty, maybe you should mass market it 