Thread: The Overheating Disco...

Hi Folks,
I have been having an overheating problem with my V8 Auto Disco 1 for a little while now. I am a bit stumped and not sure what path to follow next.

First overheated towing my horse float to a show. Got up to red as i pulled into a servo and shut it off. Steam coming from under bonnet. Opened up the expansion tank, empty. Put around 9 liters in all up. I'm guessing it had been low for a while, my OH normally drives it an mentioned hearing some gurgling noises occasionally. My fault for not checking it first. Drove 20km hwy to the show without overheating. Assumed it was just low on coolant.

Overheated after driving to pick OH up from a mates place, town driving (i wouldn't go as far to call anything in Darwin "city driving" lol!). Got to red as i pulled into our driveway. Steam, bubbling out of expansion tank.

Has overheated in similar fashion maybe 2/3 times more (this is all over a period of about 3 months).

Also it has NOT overheated (just below 1/2 way on the temp guage) and proceeded to bubble coolant out of the expansion tank once the car is shut off. This is confusing me massively!!! Any ideas on what can cause this to happen? I checked the exp tank cap for cracks and whilst the black plastic outer isn't cracked the little cover in the top of it is smashed. I have express ordered a replacement should be here Wednesday.

I *suspect* (or hope?) that this might be where it is losing coolant rather than somewhere scarier. I drained the oil and changed oil filter a fortnight ago - not milky looking at all. No sweet smell in the exhaust.

Car runs well besides a slightly lumpy idle, plenty of power pulling a float with two horses on board up hills.

I'd like to do as much of this myself as possible but if the exp tank cap isnt the problem i'm not sure where the next logical step is... thermostat? Radiator? Head Gasket (Noooooooooo!).

Please help a disco n00b!

Cheers in advance for the wealth of knowledge i know will follow!

DiscoPotato

No water in oil/ sweet smell doesnt neccarily mean you have escaped a bad head gasket. My '97 4.0 v8 ran fine, never missed a beat but the thing drank coolant like crazy. It is possible for them to fail and burn off the exhaust.

DO a leak down test, then a compression test. sad to say I bet you've lost the gasket.