Hello,

Non-mechanic here in Washington State. 98 4runner Base 2.7l 3rzFE with 270k miles. Engine threw off P0420 bad cat converter. Investigating that issue, mechanic discovered that there is carbon in the coolant but does not appear to be coolant in the oil.

The diagnosis is a small head gasket leak causing coolant to get in exhaust and vice versa, damaging the cat converter. Given the mileage, the fact my engine is leaving oil at every seal as well, and cost to replace head gasket, he thinks the engine may be due for a rebuild, i.e., pull out replace all the seals timing chain etc and maybe even re-machining of internal parts.

Mechanic says it may not be worth doing all this work, unless I really love the vehicle, which I do. So to really do it right, he thinks just as easy to pull the engine out and swap in a "remanufactured" engine as opposed to rebuilding it.

So options are,

1) do nothing, eventually my leaky old engine will be damaged by the disintegrating gasket;
(2) buy a used engine from wrecking yard;
(3) have my engine rebuilt or buy a rebuilt engine; or
(4) buy a remanufactured engine.

I have found "remanufactured" long blocks online for about $3700 from several suppliers, none for under $2k, and pull/re-install would be $2400 plus cost of new converter. I think installing a mystery wrecking yard engine sounds like a terrible idea. A "rebuilt" engine just seems like a half-assed remanufactured job and maybe just as expensive.

What do y'all think? What would you do? Recommendations for a good rebuilt or remanufactured engine? Does the labor estimate sound appropriate?

Thanks,

Dillon