Thread: When oil coolers go bad...Td5 oil cooler corrosion

My MY99 Td5 has had a niggling coolant weep/drip from the rear outlet of the oil cooler pretty much since I bought it 30 000kms ago.

I'd replaced the short hose behind the turbo (the one that exits the cooler housing to the rear) in an attempt to fix it.

When replacing this hose I was working blind with the turbo still in place. I could feel that there was an amount of corrosion on the spigot end of the cooler. I tried getting an old bicycle chain and running it over the rough and corroded surface of the spigot to make the face of it better for the hose to clamp onto.

I thought this had worked reasonably well as the spigot was less "lumpy" than when I started. But the hose to spigot union was still pretty average and it still allowed a leak. It's the easiest leak to see too as it pools on the flat surface at the back of the block - where it meets the transmission.

Anyway, the point of the thread is to show Td5 owners what the corrosoion on that spigot was like. The photo shows that the spigot was pretty buggered.

I replaced the cooler with a genuine LR part sourced through brit-car.co.uk. I think the landed cost was around the $450 mark. Install was given to Allan at Gympie LR spares and repairs. There were a few other jobs done at the same time but the total bill was in the region of $900 (full fluid and filter change (except Auto 'box), oil cooler fitting, replace front diff pinion seal and some other minor items that I can't recall.

If you've got reason to have that short hose off the oil cooler at any time try and get a phone under there to take a photo or use a mirror. I should have had this replaced much sooner than I did. If you have a weep or leak from this hose then chances are that tightening the hose clamp will simply not seal the hose against what is probably a corroded spigot.

The corrosion that was evident on the matrix inside the actual cooler did not appear to be that bad. I was expecting it to be severe but thankfully it was mostly intact. I've still got the cooler if someone wants a photo of the matrix.

It looks to me like a coolant anti corrosion failure from not being changed for many years. If your oil cooler is like that I wonder what the radiator is like.

Regular coolant changes using distilled water should completely prevent that type of damage.

My RRC had a completely clear radiator and no corrosion in the water pump, heads or elsewhere after 10years and 240KK from regular changes of coolant about every 3 years or so using Nulon Green and distilled water.
Just for saying that I will probably now find corrosion in my D2. When I bought mine it had green in it, but I changed to red , and there was some white corrosion on the stubs. Probably PO had used tap water. Such is life.

Regards Philip A