Intermittent overheating.

[TheCheng]

My friend has a 2003 Freelander 2.5ltr (NAS) which is driving him crazy. He can drive for miles over very hilly roads without problems one day, then the next day the car will go for ten minutes and then blow all of the coolant out of the pressure cap. He has had the head gaskets, thermostat and the pressure cap changed by the LR dealer but with no change. We have read all of the posts regarding this subject but they mainly deal with a permanent overheating problem, traced to the thermostat or head gasket. I do not see what could cause such an intermittent effect, as surely a warped or cracked head would blow all of the time, not randomly? He has no water in the crankcase so the cylinder sleeves seem to be OK so far.
The only theory that I can come up with now is that the water pump may be seizing up now and then. Any ideas, anyone?

[bluefreelander]

this is because the freelander runs with very little tolerance to a little bit of coolant missing, specially when the cylinder sleeves are about to dislodge, get a freelander cooling kit for it before is to late.

here is some info from landroverforums.com:
---------------------------------------------------------------------------------

Hey I get a bunch of e-mails about the kit, you can get it doing a search on e-bay

"Freelander Cooling Kit" or "Land Rover Freelander Cooling Kit "
the freelander with the first prototype is running awesome and just passed 140k miles!
also other benefits is the oil stays crystal clear between oil changes and it does not lose it's viscosity due to the high running temps.

here is the info from ebay

---------------------------------
If you have a Land Rover Freelander you know about the common engine failure, usually between 50k - 90k miles, these vehicles are nice but will not forgive you when the engine overheats, it will self destroy. the engine is was designed with different metal/steel alloys that when they overheat the expand at a very different rate and engine fails.

The entire system works great but borderline hot, so any small problems with the cooling system will be lethal, the common reason is a cracked coolant reservoir, or hose rupture, again the reservoir will crack or the hoses will fail because the engine just runs a little hotter that it should, the coolant components will crack or blow due to the excessive pressure and sustained high temperature, if you look at the temp needle, it likes to be close to the middle.

So if you have a Freelander or will buy one, do yourself a favor and buy a "Freelander Engine Cooling Kit" which is a set of relays, wires and connectors that installs in minutes and reduces the operating temperature by turning the fan (s) at a different temperatures than the programmed by factory without interfering with the a/c and other components.

This is the cheapest insurance, it will help you avoid a 5,000.00 bill replacing a freelander engine.

This is a device that prevents damage, it will not fix the damage if it already ocurred, (however it will help in cases where the damage is mild)

As all electrical components, there are no refunds, only replacement if defective. all kits are tested before shipping to insure reliability

Important: even if device fails, the factory system still works as originally described



KIT INCLUDES: DEVICE AND INSTALLATION INSTRUCTIONS

[TheCheng]

Thanks for the info, Bluefreelander. That makes sense. We noticed that the car suddenly spits out all of its coolant when it slows down after a run. While it keeps moving at speed, there is no problem, no matter what the RPM/load is and this would indicate that the electric fans are coming on just a lttle too late after the natural airflow reduces.
The temperature sensors indicate temperature by resistance change, so this cooling kit must just change the output resistance to fool the ECU that the temperature is higher at all times than it actually is. This can be done by either adding a resistor in series or parallel, depending on the type of sensor - resistance increases with temperature rise or decreases with temperature rise. Does anyone know what type of sensors are fitted?