Any way to tell which? Have a chance to purchase a beautiful 04 disco but it is loosing coolant. For the right price I have no issue buying and doing head gaskets but afaid of doing the gaskets only to find out after that the block is bad... Any way to tell?

 

Symptoms are going to be very similar... best bet is to do a compression test I think, and poke a borescope into the spark plug holes to inspect the piston heads. Cleaner piston heads on 1, 7, 2, or 8 are more likely to be head gasket related -- and can be double checked by checking compression on adjacent cylinders with spark removed. If low compression on adjacent cylinders, put a spark plug in the other one and re-test, if compression increases, then its likely the gasket.

Also, is the oil milky or show any signs of coolant getting into it? If so, much more likely to be bad block. If coolant is being burned out the exhaust... head gaskets.

 

 

Not for certain.

There's a good chance, however, that a block would crack at its thinnest point, which is behind the cylinder liners... which would often cause them (not the only cause!) to slip, giving a telltale knocknknockknock ticking.

You can lose coolant from a lot of places, though. Sometimes it's a cracked coolant reservoir or bad reservoir cap. Heck, if the Disco is running hot enough it can be boiling coolant out the reservoir overflow tube.

Sometimes it's a cracked waterpump (super easy to replace). Or cracked heads. Or throttle body plastic heater tube.


Head gasket or cracked block are not the exclusive coolant leak culprits.

 

https://www.ebay.com/itm/Block-Teste...YAAOSw3h1ZVJC4

Add to fluid without taking motor apart.