This is a LONG story with a lot of strange issues. It has gone on now for almost 8 months - I am frustrated, tired, and I just want to get my Discovery II running properly.

I'll try to keep this short without missing any details.

I have a Discovery II - 120k miles - Purchased middle of last year. 4th Discovery I've owned, and this one has had SO many issues.

It was originally brought in for what I was told was an exhaust leak inside the engine. Turned out to be the head gaskets.

Head gaskets replaced.

After that it overheated once - we assumed it was an air bubble, purged it and continued to drive. No problems for about a week. However, in the middle of Kansas it started overheating again - took it in for service, they said it was the fan.

Fan and fan clutch replaced.

Drove 60 miles. Overheated again. Had it towed back to dealership, they said they didn't know what was wrong and kept it for a few weeks. Eventually they said it was the thermostat.

Thermostat replaced.

Got the car back - everything was fine for a few weeks, but then the overheating started again - and started getting worse. Would overheat once a week but then eventually got to a point where I didn't feel comfortable driving it.

Took it into Land Rover - they said it had a crack in the radiator. Had it checked by a second mechanic who said there was no crack but that the radiator was clogged. He also said it needed the thermostat replaced.

Radiator replaced. Thermostat replaced.

Mechanic said he tested it for several hours idling in the shop and for an hour in town and said it was fixed.

Picked it up - it overheating 15 minutes after picking up. Heater runs COLD.

I've been working with Disco Mike on this one now...
Pressure tested system, no leaks.
Pressure tested cap, no leaks.
Added coolant, bled system of air per his instructions.
Drove car for the past few days - no major issues, would sometimes start to get hot and I could run the heat and get the temperature back down again without any issues. I equated this to air in the system.

However, now it seems to be back to square one again - I drove it to work today, it started overheating on the way. Turned on the heater - no hot air. It seems to get worse after driving on the highway.

It also appears to be random... sometimes it will overheat after 5 minutes of driving, sometimes not at all.

Every time I think this thing is fixed it ends up being something else - but it's always the same symptoms.

WHAT AM I MISSING HERE?!

I have never had this many problems or frustrations with a car - something is not adding up here. I've been to MANY mechanics and they can't seem to diagnose and repair properly. I don't get it!

What else can I do, what can I try?!

Current symptoms:
Overheating and boiling over - lots of steam while driving - system won't cool down, heat runs cold. I have been told this means there is air in the system. WHERE IS THE AIR COMING FROM?! There are NO LEAKS?!

 

Stop driving it before you turn that engine into a boat anchor and call me when you can.

 

"system won't cool down, heat runs cold"

Low on coolant you may not have a leak? but your coolant has gone some where.

 

I chased this kind of problem for several months after a headgasket repair. Gasket blew on left rear. I had these same symptoms with no coolant in exhaust and a coolant oil chemical test that was inconclusive but could have had a little oil. once I even drove almost 100 miles before an overheat but other times it would happen almost as soon as it warmed up. We tried everything I could find in the forums. Finally figuring it was a slipped cylinder we pulled the head off again. There was light steeming of cylinder 8 but the mechanic I was working with refused to accept this diagnosis and sent the head out to a specialist friend. Sure enough he found a teeny tiny little crack in the c. 8 head to the coolant. Welded and installed. No problems. For 4000. I hope this helps. I was at the point where I thought I was going crazy. It sounds like a lot of things can cause a problem like this in our trucks?!?!? I hope this helps!

 

Thanks Mike... I'll give you a call after work. I started driving after the pressure test because everything was fine. And, for a couple weeks everything was fine. It wasn't until today that I started seeing a major overheating issue that wouldn't cool down.

I'll explain more over the phone.

Thanks.

 

Thanks for the info - its definitely a possibility.

I'll check into this. Thanks.

 

I topped off the coolant this morning before I drove. It was maybe an inch lower than normal. But, it was getting warm last night and some may have boiled over.

It started overheating almost immediately after starting -- within 10 minutes. Coolant was topped off before driving. But, you're right - coolant MUST be going somewhere even if there isn't a leak.

 

i would borrow or rent a preasure tester bring it up to 18 pound and leave it over night. line the ground under the truck with newpaper if there is still 18 pounds in the morning then you dont have a leak.

 

I pressure tested the system - held 18 pounds of pressure for about 25 minutes. The cap also held pressure according to Land Rover dealership.

I didn't test it overnight though - I can try that and see what happens and report back.

 

if you have air in the system and a small leak, it can easly take more than 20 minutes before you see water. You should at the same time be wiggling and pulling on all the hoses and connection while it is under preasure. Thats were the hard leaks are to find, the ones that dont leak all the time.