Greetings all

I hope someone can give a little advice. I've looked through loads of posts and have some ideas, but I'd like to double check with you to make sure I'm not spending lots of money on the wrong thing. Actually it could be everything!

Car
96 Disco. Petrol
It has just over 200k KM on the clock and had it's 200,000km service late last year.
Recently changed Thermostat and Viscous unit for the fan. Changed coolant temp sensor and coolant temp gauge to VDO units.

I'll try and include as much info as possible, but guaranteed I've missed out something stupid.

Symptoms
The car has the same ticking sound in the engine that it has had since I bought it 2 years ago.

The gas from the exhaust is clear and the oil is dark and not milky.


When i turn on the car and start to drive it slowly, the temp gauge climbs slowly to about 110, then goes down to around 95 - 102. Occasionally it climbs to about 110, but then drops down to the 95-102 mark again. They are slow changes,so I don't think it is electrical connection problem on the gauge.

Hot or cold day, doesn't seem to make any difference.

If I start the car and leave it idling in the sun in 30 degrees C, it will quite happily sit there at about 95 degrees with or without the air con on.

If I take the car on the motorway and take it over 2000revs, the temperature rises drastically. (115-120 and turn it off)

If I point a IR temp sensor at the engine, The bottom of the radiator is about 15 degrees cooler, so from posts I'm guessing it needs a new rad.

If I start the engine with the reservoir top off, after a while the coolant will overflow for about 2 seconds, then go lower again. 30 seconds later this will happen again. But the water itself is not actually hot, so it's not boiling over.

If the engine gets hot and I turn the engine off, It doesn't start again for about 30minutes... I'm guessing this is some sort of safety cut off.


Personal conclusions from reading posts.
So far, various elements seem to point to everything bad... new radiator(temperature difference top-bottom), air in the coolant (head gasket?). Slipped cylinder liner./sleeve - even though I don't really know what that means (tapping sound and increase resistance in engine at revs)


I'm in Chile - there are not so many LR work shops. The local dealer only seems to know how to plug a computer into the new ones.


Any suggestions, other possible problems... or do I have a huge bill coming?

Thanks for any help or advice

David

 

1. Very good information.

2. Water expands when heated, so that is part of what you are seeing.

3. The boiling point of water changes with elevation (Chile has mountains made for Rovers), but also by pressure cap (the coolant cap). So the coolant cap has to be in good condition to keep it from overheating, especially if you have no antifreeze / coolant in the system.

4. The "overshoot" of seeing temps go up, then drop back, is the precise electronics measuring the performance of a mechnaical device (the wax ball inside the thermostat). It would be common to see it go past the "opening" temperature, then fall back. This swing will decrease as vehicle warms up. A really big swing can mean thermostat is sticking. Also, some thermostats allow a pocket of steam to form behind them and that is not good. The spring of the stat needs to be submerged. Many modern stats have a small hole or a jiggle device in the flange. Orient that at the 12:00 position to allow steam to pass by and not build up. You can also drill your own hole, like 1/8 inch. You can also test a thermostat in a pan of water on the stove.


5. You have one of the copper and brass radiators. Near me, in farm country, a small radiator shop can unsolder one of the side tanks, and rod out the calcium buildup (well water is worse than city water). They may also flush it with hot citric acid. About $75 US. A new copper radiator is big dollars, there are aluminum/plastic ones now for about $235.

6. From what you have said, overheats at higher speed, but runs OK at lower speed, the radiator is highly suspect. It can't get rid of the heat load because it is partially full of calcium.

7. The won't restart when hot could be related to ignition amplifier that drives the spark coil. You will also want to check the fuel temp sensor:

Engine Fuel Temperature Sensor (EFT)

13CU/14CU/14CUX

• NTC type sensor
• Range = 9.1k-ohms at -10 °C (14°F) to 150 ohms at 100°C (212°F). Approx. 1.2 k-ohms at 40°C (104°F)

• Located on the fuel rail forward of the intake housing, between left and right injector banks

If it was bad, unplugged, or shorted in wiring could cause trouble. So will fuel pressure leak. You can meter the pressure at fuel rail (looks like tire valve), 32 - 34 when running, when switch off should not drop by more than 10 PSI for a period of minutes. Fuel pressure regulator, and vac hoses to it could be suspect.

 

You need a new radiator from the sounds of it, it is partially clogged and it cannot handle the extra work from a larger load on the engine.
The water level rising/falling in the overflow tank is the water being pushed around by the water pump.
As the thermostat open's/closes the engine temp will rise and fall.

 

BTW, don't think a chemical flush or home brew flush alone will give you any quick relief.. See https://landroverforums.com/forum/di...-method-55045/ . Mine did not respond to distilled vinegar, commercial flush products, even removing and soaking inside of radiator with muriatic acid. When they are old they'll look like this inside (this is a two row rad, a D1 actually has a 3 row unit). The rod out is what helped mine.

 

Thank you so much for the reply, specially as it didn't include words like 'head gasket'

I'll aim for a new radiator first and see where that takes me.

btw, I knew I forgot something. I changed the fuel temp sensor last year, so I'll look at the other options you kindly listed.

Thanks again, I can hear the mountains calling already (ever the optimist)

 

A new copper brass radiator may be $600 or more, just parts. You may want to consider a trip to the radiator shop first.

 

I agree on pulling your radiator and having it looked at by a radiator shop first.

 

I really hope you are not in my boat.
I had overheating issues and tried everything, and I mean everything from rodding the radiator to replacing thermostat and water pump, etc.
Everything seemed to be fine so we invested close to 3,000 USD in tires, new suspension parts, electrical and other repairs, etc.
Three weeks later, a sound that sounded like a cracked spark plug developed and sure enough, it was a head gasket (it blew out and can be seen above the spark plugs).
I guess my point is, no matter what, don't overlook (or as they say in spanish menosprecie) the risk of the head gasket.

 

I got my new $235 [on sell for $207] ready to put in just waiting on a lower radiator hose to come in the mail. I am wondering should i go ahead and through caution to the wind and add Barr block sealer to the new system just in case?

 

No. The stopz leakz is only a temp fix at best. With new hose(s) and rad, and hopefully a new thermostat you should be good. If you decided to later you could pour in stop leakz.