hello, I have a 98 grand voyager 3.3l and 240,000 kms on it. I ahve a small pinhole leak at the top of the rad beside the cap. I guess it is the top of the plastic tank. any way of covering up this hole since its plastic and flat. thanks

You could try using a high heat epoxy filler but, that's a temp fix at best. I'd bet your hole is a tiny crack. It's only going to get worse.

very tiny cant even see it when cools down. prob from high heat plastic expands. anyway put a very thin bead of silicone on it. hope it cuires well and solves prob temporarily.

silicone won't do it, even for a temp fix...

gotta use epoxy/resin as the other poster noted... since the system has to be pressurized via rad cap or cooling efficiency goes to shiat...

do it while the vehicle is cold/ parked overnight... spray brake cleaner on affected spot, sand if u wish, and respray and let dry...

mix the epoxy together and paste it on, wait to cure... then should be good to go!

ok thanks will try tomorrow if as you say the silicone dont work.... 2 part high heat epoxy