Re: Any Land Cruiser Owners?
Hi All,
We are on our second 80 Series, a 1997 40th Anniversary petrol auto. (1FZ 80). I bought it to transport my darling wife. My gal is quadriplegic following use of a product called L-TRyptophan back in 1989.
The height of the front seating is perfect to allow me to lift her straight in and out without too much back strain. Her mobility equipment easily fits into the back without folding down the rear main seats. And we also tow a heavy caravan which is specially fitted out to accommodate our needs. Great rig for the purpose.
In November of 2004 at around 85000 miles, our engine succumbed to a catastrophic failure akin to the many failures reported in the smaller Toyota vehicles and some other makes of vehicles. Bitumen (yes the type of stuff that some roads are made of) accumulated within the engine lubrication system. Varnish from the bitumen set in the close running clearance of the cam followers and locked them. The subsequent attempt to crank the engine broke cam shafts, cam cogs, chain and guides. Ya don't expect that!
Oil and filter changed regularly at around 3000 miles. No warning, it just broke on the first start of that day.
At that time I was blissfully unaware of the massive problems of this nature in Toyota vehicles. Had I an inkling I could have easily detected the ensuing potential problem, prevented the failure and corrected the cause of the bitumen accumulation.
And by the way, the cause was not PCV system related, or oil type related, or in any way due to faulty maintenance. Put simply, the cause was excessive heat build up in the block.
But the temperature indication system never waivered from central on the guage when warmed. So you might ask how this could be. Well; there is a direct relationship between the guage always looking good and excessive heat potentially accumulating in the block.
The evidence is unmistakeable, cogent and overwhelming when studied as I have:
Firstly, the head gasket coolant ports restrict the flow of coolant upwards to the head.
Secondly, cavitation induced by sharp edge restrictions across the coolant pump outlet duct further inhibit coolant flow. In other words, though the cooling system appears to function magnificently even under the most severe conditions, mine was fatally flawed. A little bit of logical thinking about the mass and surface area of the aluminium head, cam cover and inlet manifold in a stream of cooling air will tell you that the actual flow of heated coolant that reaches the head is being cooled very nicely. The trouble is that the real heat load that can accumulate in some operating conditions isn't reaching the head. The temperature sender is in the aluminium head adjacent to the outlet port to the radiator.
And one more causitive factor in this saga: The sump pan cannot be completely drained. The drain plug is not situated at the lowest point. And what you can't see from the outside; the captive nut that the plug screws into protrudes about half an inch into the sump. Thus nearly an inch of muck remians no matter how often you drain or flush the system. Consequently, as well as clagging up the top-end and all internal cooler aluminium surfaces (where the bitumen condenses from the clouds of smoke cooked off from the very hot crankcase surfaces) bitumen that drips downwards accumulates at the lowest point. Now that of itself mightn't be too much of a problem except that the oil uptake draws strongly from the very bottom, just where the dregs accumulate.
I've fixed mine by recalibrating the head gasket holes to ensure that flow from the pump is not restricted to the point that cavitation occurs. I have also smoothed the flow path to remove the sharp edges that otherwise also had to result in cavitation. I repositioned the sump drain plug to the lowest point and reversed the captive nut so that the protrusion is on the outside.
To monitor the effectiveness of my modifications, I have placed a permanent thermocouple into the middle of the body of oil in the sump. I am very pleased with the results. Normal running sump oil temp is 85 - 87 Degrees Celsius. Under sustained high power up hill it runs up to 94 Degrees. I understand that LandCruiser sump temp is normally 100 Degrees Celsius plus.
There is more data and it is all good.
I'll be happy to talk more and particularly to give people the benefit of my hindsight as to the clues that were there had I been looking for them.
But I'm very interested to hear from other LandCruiser owners who have had problems with what I regard as erroneously called 'sludge'. The incorrect use of that term can wrongly lead people who might not know better, to accept the notion that their problem is their fault when plainly is most unlikely to be their fault at all.
'Sludge' is a grey to black slimy muck formed when blow-by (gasses getting past pistons into the crankcase) and moisture (condensation) combine. Many years past, detergent oils with dispercancy factors were introduced to keep these two components separate and thus prevent the formation of sludge. PCV systems wer later introduced to draw off blow-by gasses and evapourated moisture. They were never intended to draw off the clouds of smoke from oil mist overheated when contacting excessively hot surfaces. The passing of smoked off oil into the combustion chambers produces heavy pollution. And on the way to becoming pollution, it clags up inlet valves and cokes up the tops of piston, not to mention what it does to the ring grooves and little-end freedom to float.
Kind regards to all you Cruiser owners
Ole Cruiser1
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