Defender td5 with possible headgasket failure

Hi all,
My defender td5 has for the last two weeks started blowing steam from the cap of the coolant reservoir and when I remove the cap I can hear a 'gurgling' sound coming from the reservoir. It only does this on long journeys, driving in the highest gear. Before this started I had the oil cooler replaced. is it still okay to drive the car like this for long distances without the cap of the coolant reservoir?

No

Is there any oil in the water?
Is it losing water?
Is there any water in the oil? White creamy Mayo like substance in oil cap.
What does temp gauge read?

Td5 heads are prone to warping and cracking so to continue to drive in any capacity could cause £££ of damage

any smoke out of the exhaust?

oil in the water was already encountered and resolved; the oil cooler change. Temp gauge stays within normal; only on long distances I have noticed gauge to jump to red area and then return back to normal. The jumping off the gauge is also cause to a sudden decrease in power. No smoke out of the exhaust

I'd suspect the head gasket. It may be the cause of your previous oil cooler fault too. Don't drive with the cap off, the cooling system is designed to run under pressure. get it sorted asap.

have already booked a checkup by the dealer this Friday; head gasket change will definitely take time and money! Hoping for something less dramatic

it's not cheap bit not too drastic. the only problem may be if the head is badly warped or cracked. get a pressure test on the head before they put it back on!

I was also wondering if something in the cooling system has gotten clogged since the oil cooler was leaking before this happened

Td5 heads can do some weird things, one that happened to me was the engine gets the slightest bit hot and the head starts to shuffle sideways and the plastic locating dowels cant stop it, if left it goes far enough sideways that the valves can hit the cylinder sidewall and scrap the engine.
Later engines had steel dowels.
I wouldnt be running it at all until problem sorted.

Thanks guys, will have the car checked; don't want to wreck the engine, but it does test my patience. I have had oil cooler issues, clutch master and slave changed and now head gasket!
the disco I have also needs to have its front wheel bearing changed; Where I live everything parts are double the expense; I really envy the guys with land rovers in England

What disco have you got? if D3 dont fit the cheap bearing as you will be doing it again within 18months.

nope, have a d2 td5; both cars have same engine

just talked to a guy from a non land rover related garage and he told me that if the defender had a head gasket failure it would show the symptoms on short distances itself. is this true?

or could it also be the thermostat that is stuck in the closed position thus with holding the coolant from going in the radiator; I just flushed the cooling system again and I saw no sign of any debris or oil.

during the last post and now i had changed the cap on the coolant reservoir; the rubber inside the old one was seriously deformed. This seemed to have solved the water boiling problem so i was happy that the overheating issue was resolved. Some days ago i went again on another trip involving serious off road parts and mountain climbs. this time the car overheated with the temp needle not budging from the overheat part of the gauge. Being towed back home i discovered later on that the engine oil was full with water. I assume that this definitely means head gasket?

could be a cracked head or block. get the head pressure tested and move on from there!

That's why it should not be driven until you know what the fault is!
The engine is probably toast now if it was full of water.
Although l hope not.

Could the water have entered via the oil cooler? However when I drained the engine oil it first started with just water afterwards the oil. Water still looked normal, the same for the oil.

Oil and water don't mix. The oil will always float to the top, so you'll get water draining out first and then oil.

Hopefully if you fix the fault the engine will still be OK.

i am just referring to the appearance of the 'normal' water and oil because i have had oil coolers going bad and when you drain the engine everything is like thick greaish mud. i might start small and have the oil cooler pressure tested and move to the head from there. yesterday i mailed a dealer in the netherlands about the posssible head gasket failure and he told me that on td5's the head gasket never fails; it's always the head that has gone awry