1997 land rover discovery 1 - My son took the rover over the mountains a few months ago. The beast started spraying coolant all over the engine compartment. we parked it for a few months until I could find some time to get to it. turns out it was coming out of the horribly designed, black, clamshell coolant reservoir (thank you landroverforums for that diagnosis). Waited another couple of months cause, you know, stupid work and all, and finally replaced the reservoir. Fired up the beast and all seemed ok. Had my son take it around the block and by the time he got back it was dumping coolant somewhere near the bottom of the engine and the firewall. does this sound like head gasket or is there something else I can check first?

 

Are you getting a good seal from the reservoir cap? A bad cap and cause a coolant spill.

 

How would I test that? I got a new reservoir but used the old cap. It seems unlikely with the amount of coolant leaking from underneath the engine, but Ill try anything

 

High pressure caused the reservoir to split, so maybe found another weak spot. Maybe try letting it warm up at idle with the cap removed to prevent pressure. Watch for bubbling in the coolant, or use a tester with the blue liquid to check for exhaust gasses. Trace any leak trails up to the highest point.

PS. Some folks run Rover V-8s with the pressure cap loosened to prevent pressure induced cooling system troubles.

 

My thought was to get a tester with the blue liquid to check for exhaust gasses.
Do a coolant pressure test to 18 pound, you'll find the leak real quick.


Interesting I had never heard some Rover owners loosening the reservoir cap to prevent pressure. Now I am curious as to how loose is acceptable.

 

Loosen cap on reservoir just enough to bleed pressure and not spill coolant. Maybe 1/2 to 1 turn, more or less. One of the uber-posters did a technical write-up of pros and cons of this mod. Biggest con is tendency of coolant to boil at high elevations, over 6000 ft or so, depending on glycol concentration. Could have been Extinct or Best, don't remember. Loose cap is a good thread for the Tech Section sticky. The thread might be in the D2 forum. My '94 would spill a bit with the cap loose unless I ran the coolant level about an inch below full cold.

 

I’m pretty sure it’s Extinct, and in the D2 section.

 

Thanks for the reply.
The loose cap becomes some tricky business for me. The Rover doesn't like tricky.

 

Telletale signs:

1) Bubbles in and/or smell combustion gases in coolant reservoir.

2) Hoses REALLY hard, like a LOT of pressure, (with cap on tank).

3) Gurggling sound from the heater core in the AM when you go to start it?

4) White smoke when you start it ...or when running (smell it - carefully). If it smells like antifreeze...then it is.

5) Spark plug which is really clean and looks like new compared to the others. (the steam cleans them)

Also, rule out the quirky lower radiator hose. That can develop a pinhole or looseness at some location and squirt water up into the engine. You never want to take that lower radiator hose for granted. A bad one of those can ruin an engine (if it blows/overheats/drops a liner).

I just leave the cap loose on mine. Then it doesn't build up pressure. But best to replace the HG's. Enough coolant exposure will ruin the catalytic converters and that's another big expense (and constant dash light).

 

Hey Mark,
Your logic is aligned with JohnZo on the loose coolant cap as to not build up pressure. By keeping it loose would that not allow air into the system?
Still trying to understand how loose should loose be. Is this loose cap concept more of a go for off roading or a daily driver?

Thanks