OK to answer the questions.
Don't think it has anything to do with driving style - mine used to get a real mix of driving - between 30 and 40 around town and country roads, up to 85 on the motorway (when it was clear but not on our infamous M25 London ring road where the average speed is dead stop). Driving in the UK is generally faster than the US or Canada but not as fast as Germany or France (they're all mad in France - only kidding).
Some people are running additional gauges as the water temp gauge on eth 2LT/2LTE engine has the sensor too high up the engine - as soon as it loses a little water then you get no reading. A few people put additional sensors lower down on the bottom of the Rad. A few people have also removed the sensor wire from the additional electric fan so it runs all the time when the ignition is on.
When the Head goes, you generally get no warning, it overheats because the head has gone and pumped all the coolant out of the system. Heads tend to go between the Exhaust valves and the pre combustion chambers and also between the inlet and exhaust valves - mine had 6 cracks, between all the valves and between the exhaust and pre combustion chamber on 1 and 4.
The EGRs on the 2LT / 2LTE are vacuum operated and they often stick open allowing the Exhaust gas to recirculate all the time rather than just under heavy acceleration, it has been said that this can cause uneven head temperatures promoting the cracking. A common mod over here is to remove the EGR from circuit either blocking the port on the exhaust manifold or just plugging the activation pipe. This also extends the life of the oil as there are less carbon deposits comming back into the engine as well.
Another thing that seems to help is by putting a large front pipe on the Turbo (Dump pipe) - moving up to a 3 inch one. This not only allows the Turbo to spin up quicker which improves the power of the engine, but also allows the turbo to get rid of the exhaust gasses and therfore some of the heat quicker.
So far I have changed 7 cylinder heads on Surfs (in my spare time with a friend) for various people and also for my own. Average time to do it is 12 to 14 hours so it's not a job you want to take on lightly although it is not that difficult.
Also in terms of temperature, mine let go in the Summer but lots let go in the winter so it doesn't seem to have anything to do with the air temperature.#
To be honest the cooling systems on the Surfs/Hiluxes seems to be borderline and needs to be running 100% to not give any problems. Mine was fine after the head was replaced however I sold it on after 2 years and the guy who bought it from me had the Water pump let go on him and cracked the head as he didn't pull over quick enough - wish I'd changed the water pump now as it's real cheap to replace and easy while the head is off, however there was nothing wrong with it at the time.
I think that when it is 100% sorted the 2LT /2LTE is a great engine - almost as many made as the Small Block Chevy, however I wouldn't say that economy is good, my Cruiser with the 1HDT is much more economical even though it is more powerfull and the Cruiser is a lot heavier. However when well looked after and with a new head, the 2LT will last as long as a 1HD-T engine (over 300K miles) without major problems. It's also pretty easy to work on - the 1KZTE is easier though apart from the Turbo being tucked well out of the way.
If anyone wants to have a look at the other forum, log on to http://www.hiluxsurf.co.uk and you can browse through the pretty active forum and find out lots about the 2L engines and derivatives as well as the 1KZT engines in the newer Surfs.
Don't think it has anything to do with driving style - mine used to get a real mix of driving - between 30 and 40 around town and country roads, up to 85 on the motorway (when it was clear but not on our infamous M25 London ring road where the average speed is dead stop). Driving in the UK is generally faster than the US or Canada but not as fast as Germany or France (they're all mad in France - only kidding).
Some people are running additional gauges as the water temp gauge on eth 2LT/2LTE engine has the sensor too high up the engine - as soon as it loses a little water then you get no reading. A few people put additional sensors lower down on the bottom of the Rad. A few people have also removed the sensor wire from the additional electric fan so it runs all the time when the ignition is on.
When the Head goes, you generally get no warning, it overheats because the head has gone and pumped all the coolant out of the system. Heads tend to go between the Exhaust valves and the pre combustion chambers and also between the inlet and exhaust valves - mine had 6 cracks, between all the valves and between the exhaust and pre combustion chamber on 1 and 4.
The EGRs on the 2LT / 2LTE are vacuum operated and they often stick open allowing the Exhaust gas to recirculate all the time rather than just under heavy acceleration, it has been said that this can cause uneven head temperatures promoting the cracking. A common mod over here is to remove the EGR from circuit either blocking the port on the exhaust manifold or just plugging the activation pipe. This also extends the life of the oil as there are less carbon deposits comming back into the engine as well.
Another thing that seems to help is by putting a large front pipe on the Turbo (Dump pipe) - moving up to a 3 inch one. This not only allows the Turbo to spin up quicker which improves the power of the engine, but also allows the turbo to get rid of the exhaust gasses and therfore some of the heat quicker.
So far I have changed 7 cylinder heads on Surfs (in my spare time with a friend) for various people and also for my own. Average time to do it is 12 to 14 hours so it's not a job you want to take on lightly although it is not that difficult.
Also in terms of temperature, mine let go in the Summer but lots let go in the winter so it doesn't seem to have anything to do with the air temperature.#
To be honest the cooling systems on the Surfs/Hiluxes seems to be borderline and needs to be running 100% to not give any problems. Mine was fine after the head was replaced however I sold it on after 2 years and the guy who bought it from me had the Water pump let go on him and cracked the head as he didn't pull over quick enough - wish I'd changed the water pump now as it's real cheap to replace and easy while the head is off, however there was nothing wrong with it at the time.
I think that when it is 100% sorted the 2LT /2LTE is a great engine - almost as many made as the Small Block Chevy, however I wouldn't say that economy is good, my Cruiser with the 1HDT is much more economical even though it is more powerfull and the Cruiser is a lot heavier. However when well looked after and with a new head, the 2LT will last as long as a 1HD-T engine (over 300K miles) without major problems. It's also pretty easy to work on - the 1KZTE is easier though apart from the Turbo being tucked well out of the way.
If anyone wants to have a look at the other forum, log on to http://www.hiluxsurf.co.uk and you can browse through the pretty active forum and find out lots about the 2L engines and derivatives as well as the 1KZT engines in the newer Surfs.
I think I got "photographed" about 3 times that night 
