Thread: Disco 4 Buying advice - coolant leak, air-con not cold

Coolant system is mainly plastic parts that fail due to heat cycles, the gitting into the block is a known issue with the later D3s and early D4's. Pita to get to. There's also a breather plug in the top crossover pipe, these can leak, but are pennies to fix and easily accessible.

What you describe sounds like the oil cooler may have failed/be failing, check the valley between the manifolds and also the expansion tank.
They fail "safe' in that you either leak oil into the coolant, or coolant out to atmosphere, rarely coolant into oil. Cooler is nestled under the intake between the v, relatively easy to change out.

Coolant system flush is recommended, use demin water and flush a few times, refill with correct concentration long life coolant.

Re A/C, typically the pcv in the compressor sticks, can be unstuck with a reverse shot of compressed air, but you still need to empty the system and get it recharged. likely a new compressor and full ac system flush will be needed.

If everything else is OK, use these to drive the price down. For coolant system repairs, including oil cooler, I reckon 1.5-2k, A/C $2400 for a new compressor with labour to pull the old one and refit.

As above but with mine leaking coolant in a similar area it was the plastic coolant piece in the middle of the V at the front of the engine.

Great info, thank you. Have contacted seller and will hopefully negotiate a good outcome for both of us.

Originally Posted by Eric SDV6SE

Coolant system is mainly plastic parts that fail due to heat cycles, the gitting into the block is a known issue with the later D3s and early D4's. Pita to get to. There's also a breather plug in the top crossover pipe, these can leak, but are pennies to fix and easily accessible.

What you describe sounds like the oil cooler may have failed/be failing, check the valley between the manifolds and also the expansion tank.
They fail "safe' in that you either leak oil into the coolant, or coolant out to atmosphere, rarely coolant into oil. Cooler is nestled under the intake between the v, relatively easy to change out.

Coolant system flush is recommended, use demin water and flush a few times, refill with correct concentration long life coolant.

Re A/C, typically the pcv in the compressor sticks, can be unstuck with a reverse shot of compressed air, but you still need to empty the system and get it recharged. likely a new compressor and full ac system flush will be needed.

If everything else is OK, use these to drive the price down. For coolant system repairs, including oil cooler, I reckon 1.5-2k, A/C $2400 for a new compressor with labour to pull the old one and refit.

Well it was a good guess. Seller repaired the oil cooler (along with thermostat housing and breather tube), and I picked it up yesterday.

Still need to fix the A/C - it's making a definite whine when it's on. Let's hope it hasn't spewed grey death through the system like I've read about elsewhere.

Thanks!

We were told the AC compressor needed replacement - $3k and then went elsewhere by luck and PCV for $1100. So check it out, the PCV is really common on these.