Hey everyone, I have a T100 with the 3vze thats been leaking coolant for a few weeks now. I had the day off today to look into it more and found what looks to be a leaking freeze plug. It is the lower most freeze plug on the passenger side. I saw on a forum where they pulled the entire engine to replace the freeze plugs. I don't have the means of doing that, so if there are any other suggestions on how to replace them that would be greatly appreciated. Also as a preface, I double checked and made sure it wasn't the U-shaped bypass hose behind the plenum. There doesn't seem to be any moisture above this freeze plug. Any and all help is greatly appreciated.

 

Also, does anyone know what diameter this freeze plug is? Everything I see online says this engine only uses 35mm freeze plugs, but the one above the problem plug, clearly says 30mm... Regardless I can't figure out what size the little leaky guy is...

 

According to Toyota, the plugs in the block are 35mm. https://parts.lakelandtoyota.com/sho...rimLevel=18373
Unfortunately, Toyota doesn't show any plugs in the heads. https://parts.lakelandtoyota.com/sho...rimLevel=18373
(I've never had mine out of the engine bay, so I can't say that I know what the back looks like.)

Have you tried just measuring the leaking plug?

 

If there is a marking on it you could look at the driver side head on the front as it would have the same plug.
Not sure of your working area to get at plug on a T100 but on my SR5 there would not be enough working room to remove and replace plug without at least removing the head.