Hey y'all,

I tracked down a burning coolant smell on my 2000 4.0 OHV 103K to slow leaks on the outsides of each head. Noticed the smell and very slow loss of coolant (never hitting the ground) over a year ago, but oil was always clean and the truck has never overheated, so I kinda just forgot about it after replacing thermostat housing and hoses didn't solve the problem. Finally saw this corrosion while replacing the steering rack last week. I've flushed the coolant regularly since owning but I remember my first flush being pretty nasty. Temperatures here are pretty extreme and can swing 60+ degrees in a day/night cycle, so I'm thinking a bit of corrosion plus this aluminum head thing in drastic temp changes equals room for leaks. Other thing to note is a brief rough idle on startup, especially after a cold night (I think I remember cylinder 4 misfire codes triggering briefly during these rough idles and clearing after, but might have only been before I replaced coil pack, plugs and wires). My questions are; could this be more than a gasket issue or heads needing machining? Could coolant be getting into cylinder 4 (driver side where the leak looks worse) causing that idle, but not show up in the oil? Block test showed nothing, so as far as I can tell the only leaking that's happening is coolant to the outside, but maybe I'm missing something.

It's my only vehicle and I have no garage, so a tear down isn't possible without getting myself into a dusty mess. I also have to make two 500 mile trips in the next two weeks. But if I do find a way to work in a garage, any idea about what else I might discover down there?

And lastly, thoughts on trying a bottle of gasket sealer??

Thanks for reading,
Ian


driver side

passenger side

 

Oh also, could the leak be at the intake manifold instead?