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- #21
Who can guess ?
B,
Volume wise, all of the coolant circulates through the filter in a reasonably short period of time. I haven't measured the flow rate, but I imagine it is not very long before all of the coolant makes a pass through the filter; after all, there is only 4 gallons of coolant in total. So it becomes a matter of chance as to whether or not any particular particle gets caught by the filter or the radiator first. And of course, the filter is much more efficient than the radiator in terms of capturing particles.
As far as the cause of the sludge, I can only guess. First, I don't know what it is. Somebody previously stated, I think on this forum, that it is left over casting sand. Well, I don't know what casting sand looks like, but this stuff, when dry, is very fine, like talcum powder. What I do know, is this is the only engine I have owned that I have ever seen with this problem. And there are only two things that are unique about this engine compared to all others I have owned. 1) It has an aluminum radiator and 2) it started life with Toyota red coolant. So if i had to bet, I would bet that it is a problem with the Toyota red coolant. But that is just a guess, and I have no data to back that up. Also, it must be something else than just the coolant, perhaps poor maintenance (not by me!), mixing coolants, a bad batch of coolant, or something, as (I presume) most owners are not seeing this issue. But it is common enough that a number of reports have shown up here and in other forums specific to land cruisers.
When I bought the truck, it had what looked like new, clean Prestone in the radiator. 10K miles later I dipped my finger in the top of radiator and came up with sludge. Upon draining the coolant what looked nice and green in the radiator looked brown and nasty in the bucket. Perhaps it was a mix of green and red coolant, I don't know. I do expect that had I done a more thorough examination (I.E. drained radiator and examine dcore) when I purchased that the problem would have been evident then.
After cleaning the radiator I have been using Prestone, based on having used it for years in other engines with aluminum heads with no problems.
I do expect that the filter will make a major difference in the rate of accumulation of sludge in the radiator. I won't know for sure until I pull out the radiator and have it flushed again and then run it for a few thousand miles.
A side benefit of the filter is that it should prolong the life of the water pump. That in itself would not be sufficient justification to go to all the trouble to install one. My main motiviation is to avoid a clogged radiator and a overheated engine. Clearly, In my experience, just cleaning the radiator and changing the coolant is not sufficient to cure the problem.
Rich
B,
Volume wise, all of the coolant circulates through the filter in a reasonably short period of time. I haven't measured the flow rate, but I imagine it is not very long before all of the coolant makes a pass through the filter; after all, there is only 4 gallons of coolant in total. So it becomes a matter of chance as to whether or not any particular particle gets caught by the filter or the radiator first. And of course, the filter is much more efficient than the radiator in terms of capturing particles.
As far as the cause of the sludge, I can only guess. First, I don't know what it is. Somebody previously stated, I think on this forum, that it is left over casting sand. Well, I don't know what casting sand looks like, but this stuff, when dry, is very fine, like talcum powder. What I do know, is this is the only engine I have owned that I have ever seen with this problem. And there are only two things that are unique about this engine compared to all others I have owned. 1) It has an aluminum radiator and 2) it started life with Toyota red coolant. So if i had to bet, I would bet that it is a problem with the Toyota red coolant. But that is just a guess, and I have no data to back that up. Also, it must be something else than just the coolant, perhaps poor maintenance (not by me!), mixing coolants, a bad batch of coolant, or something, as (I presume) most owners are not seeing this issue. But it is common enough that a number of reports have shown up here and in other forums specific to land cruisers.
When I bought the truck, it had what looked like new, clean Prestone in the radiator. 10K miles later I dipped my finger in the top of radiator and came up with sludge. Upon draining the coolant what looked nice and green in the radiator looked brown and nasty in the bucket. Perhaps it was a mix of green and red coolant, I don't know. I do expect that had I done a more thorough examination (I.E. drained radiator and examine dcore) when I purchased that the problem would have been evident then.
After cleaning the radiator I have been using Prestone, based on having used it for years in other engines with aluminum heads with no problems.
I do expect that the filter will make a major difference in the rate of accumulation of sludge in the radiator. I won't know for sure until I pull out the radiator and have it flushed again and then run it for a few thousand miles.
A side benefit of the filter is that it should prolong the life of the water pump. That in itself would not be sufficient justification to go to all the trouble to install one. My main motiviation is to avoid a clogged radiator and a overheated engine. Clearly, In my experience, just cleaning the radiator and changing the coolant is not sufficient to cure the problem.
Rich
. I didn't actually expect anybody to guess I would be mounting a coolant filter. It's kinda of a nitch application in a land cruiser. I would be glad not to need one.
