Nice radiator surprise

[turbocruiser]

Wile we have a group of clean rad owners here wonder if you guys have done anything diffrent then the rest of us? If it is casting sand then it is just luck of the draw, if it is related to corossion or electrolisys then you guys or your PO's have been giving diffrent care or some other reason why the sludge did not develop.

Any of these pristine rad's run on Toyota red thier entire life?

As I recall, several here, including Dan, have owned their rigs since they were new and they did wonderful maintenance, always used RED, always flushed, and still saw some sludge on the first flush!!! That would make me want to think that the casting sand and release agent was simply not washed out of the blocks at the factory. A huge oversight considering the harm it can cause and also considering Toyota Quality Control in general!!!

 

[Rich]

Thanks Rick.

 

[MoJ]

If as reported, it's been discovered relatively early in the life of a 1fz, I can't imagine it being casting sand because it's been reported over a range of model years. I.e., it would have been discovered by Mr. T. in 93/94 and then resolved as it would be an easy manufacturing defect to prevent once the problem had been discovered. From a manufacturing standpoint, a problem like that is generally taken care of quickly if the solution is cost effective. I'm thinking it's the result of some inherent design defect that would have required major process or component redesign to avoid it from happening, not something as simple as making sure the block was good and clean prior to install. My 2 cents.

 

[turbocruiser]

If as reported, it's been discovered relatively early in the life of a 1fz, I can't imagine it being casting sand because it's been reported over a range of model years. I.e., it would have been discovered by Mr. T. in 93/94 and then resolved as it would be an easy manufacturing defect to prevent once the problem had been discovered. From a manufacturing standpoint, a problem like that is generally taken care of quickly if the solution is cost effective. I'm thinking it's the result of some inherent design defect that would have required major process or component redesign to avoid it from happening, not something as simple as making sure the block was good and clean prior to install. My 2 cents.

Not to argue as such, but then why, if its some inherent design defect, do only some have sludge? Again, not to argue, just to learn.

 

[MoJ]

Can't answer that and you may be right, it may be a root cause that's a bit more random than what I made it sound. However, with all the years of experience Mr. T. has, I find it hard to believe casting sand would sneak by over a wide range of years, seems like too much of a rookie mistake. As a supplier to both Honda and Toyota I can say that they don't let obvious problems like that get by them for long once it's discovered. Whereas the American manufactures tend to make threats when theres a problem Toyota and Honda tend to instead send a dozen people to your plant that don't leave until they're 110% satisfied it's been fixed. After that they add detection of that defect to they're quality plan making it a long term addition to they're inspection system.

 

[flintknapper]

Not to argue as such, but then why, if its some inherent design defect, do only some have sludge? Again, not to argue, just to learn.

I agree that a design defect would be an unlikely cause. The reason I say this is because a defect is a "constant" and would be present in every casting.

The reason Toyota is so sucessful with their quality control is because they eliminate as many "variables" as possible.

One small variable in the production process could easily cause a problem affecting only certain vehicles over several model years.

Example: If Toyota's block castings are a "vendor part" then perhaps that vendor ran out of the casting sand that they normally use and purchased some from another mfg., this might have been the case over several years.

Casting sand is always a mix of sand, clay, and sometimes other organics, and is wetted a certain amount before final forming. In addition....some type of release agent is used to keep the sand from sticking to anything it is not supposed to.

If this mixture differed enough to allow it to stick to the casting then you could indeed see a problem from time to time.

Toyota's process for "flushing" or removing casting debris might be fine for a "normal" block, but suppose the "tainted" block still had sand attached that would only come loose later after many heating and cooling cycles. If this has not been reported to Toyota in significant numbers then they would not consider it a problem.

Now, I have no idea how Toyota cleans their parts or even how they are produced, and the above is clearly hypothetical.

One thing is certain though.....if the materials present in a "sludged" radiator are indeed sand, clay, etc.....the engine is not "making" it.