Landrover: Head gasket, thermostat or radiator cap?

salad17

Landrover discovery 1998 series 1

Here's a quick look at the problem:
https://youtu.be/wOi0BysfsSo

Ok so pulled over with an overheating problem.

Big pressure buildup in the coolant reservoir. Spewing copper brown liquid when I open it. My initial thought is the obvious head gasket.

Then I watched this video:
https://www.youtube.com/watch?v=IrOfR4XJZR8

which suggests that if I squeeze this pipe that is normally able to withstand 15psi, bubbles should not appear in my coolant reservoir. So when I squeeze the pipe, bubbles do appear in my coolant reservoir, which suggests to me that there could simply be a valve failing between the pressurised cooling system and the coolant reservoir? The valve that is normally on the radiator cap?

Does that make sense?

Thanks!

dooroy

The video of what happened when you opened the cap would suggest head gasket failure or maybe a crack in the cylinder head.
A failed /closed thermostat could cause that also.
Were you long driving when it over heated ?
Was there coolant in the system or just plain water ?
Was the level going down - the water pump in the Tdi is quite high up and a
drop in coolant level can cause overheating as the coolant isn't circulating due to the WP being above the coolant level . A well documented design flaw.
The system shown in the second video is not the same as what you have - in the Land Rover the plastic container becomes pressurised - and they can sometimes crack and cause a leak.
Refilling and bleeding the system can be tricky due to the system design - have a read through this ;
https://forums.lr4x4.com/topic/48353-bleeding-cooling-system-300-tdi-discovery/.
There is a lot of info available online for the 300 Tdi - and well worth going through.
Hope this helps.

salad17

dooroy wrote: »

The video of what happened when you opened the cap would suggest head gasket failure or maybe a crack in the cylinder head.
A failed /closed thermostat could cause that also.
Were you long driving when it over heated ?
Was there coolant in the system or just plain water ?
Was the level going down - the water pump in the Tdi is quite high up and a
drop in coolant level can cause overheating as the coolant isn't circulating due to the WP being above the coolant level . A well documented design flaw.
The system shown in the second video is not the same as what you have - in the Land Rover the plastic container becomes pressurised - and they can sometimes crack and cause a leak.
Refilling and bleeding the system can be tricky due to the system design - have a read through this ;
https://forums.lr4x4.com/topic/48353-bleeding-cooling-system-300-tdi-discovery/.
There is a lot of info available online for the 300 Tdi - and well worth going through.
Hope this helps.

I had been driving it a good bit, couple of hours and pulling a trailer on a hot day!

Just water in it, as far as I know, and the level kept dropping. But also spewing out of the filler lid if I had the engine on. I pulled in to let it cool for an hour with heating on, then drove to a petrol station and refilled water but it just kept spewing out of the lid.

Great thanks, I’ll have a read through. I’m just trying to see if it’s worth saving at this point, or scrapping. Would be a shame to scrap.

dooroy

If it starts spewing out water as soon as you start it then the head gasket is well gone - or you could now have a crack in the cylinder head ( common enough).
Pulling a trailer on a hot day would certainly show up any weakness in the system and the fact that water pump is high up would add to the problem when the level was dropping.
You could remove the head and if gasket is obviously gone then a skim , new gasket etc and you could be back in business.
It would be advisable to have the head pressure tested just in case.
If head is cracked then a much more expensive repair.

Jimmy.

Isn’t being constantly in mechanical trouble part of the romance with a land Rover?
To answer your question op the first video makes no sense.

salad17

Haha the first video is my landrover, the end of the video was just after it overheated.

If it makes no sense, then I guess that's the joy of having a landrover right there?!

salad17

dooroy wrote: »

If it starts spewing out water as soon as you start it then the head gasket is well gone - or you could now have a crack in the cylinder head ( common enough).
Pulling a trailer on a hot day would certainly show up any weakness in the system and the fact that water pump is high up would add to the problem when the level was dropping.
You could remove the head and if gasket is obviously gone then a skim , new gasket etc and you could be back in business.
It would be advisable to have the head pressure tested just in case.
If head is cracked then a much more expensive repair.

Thanks for the tips. Yeah I'm not looking for any expensive repair, as it needs welding on the chassis already so it wouldn't be worth it.

I would imagine taking the head off is beyond my abilities!

dooroy

Taking the head off is easy enough - just keep the push rods in order and twist each pushrod as you lift it so the cam follower remains in position.
There are one or two head bolts which are difficult to access - otherwise straightforward.
As these jobs go - one of the easier ones .

salad17

dooroy wrote: »

Taking the head off is easy enough - just keep the push rods in order and twist each pushrod as you lift it so the cam follower remains in position.
There are one or two head bolts which are difficult to access - otherwise straightforward.
As these jobs go - one of the easier ones .

Ok thanks, good to know. I'll find some good walkthroughs and then try and build up the courage to give it a go!