Catastrophic fail today

[IanRTL]

Originally Posted by pudgiesinwaverly

When I am due for a timing belt I am also going to replace the head gasket.

For what reason? It is extremely rare for an actual head gasket to fail on a RL. If it isn't broken, don't fix it. You'd have a pile of extra money into it and it wouldn't be necessary.


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[laserguy]

Originally Posted by FineLine

Speed, for galvanic corrosion to occur the dissimilar metals need be in contact with an electrolye - a solution capable of conducting electrical current. In this case it would be a mixture of water and road salt, sodium and calcium chloride. The different electrical potentials of the metals isn't significant until the electrolyte is introduced. From the pictures I've seen it doesn't look like the corrosion is occurring from the coolant or transmission fluid being the electrolyte. It is external corrosion of the fitting washers, one is a cathode and the other is the anode with the result being an increase in the thickness of one of the washers. This forces the fitting assembly to move backwards out of the transmission heat exchanger which compromises the internal seal. At that point the two fluids can mix or if your lucky the entire fitting pops out and you lose both fluids before they mix and circulate through the engine and transmission. I think a periodic application of naval jelly on the washers would help considerably.

Glad I am not alone sharing the same thoughts, I know nothing about galvanic
rust, it just made sense to me the the washer gets rusted and damaged to the point that it serves no purpose causing the damages described and seen in every case.

[thooks]

Am I the only one that thinks a radiator blowing out (at 100k miles) isn't a "catastrophic failure" ???


Uh, a 'catastrophic failure' would be the engine locking up tighter than strings on a banjo.

[S1njin]

I would assume its catastrophic if the radiator also takes the transmission along with it due to the fluids mixing.

[IanRTL]

If it were just the radiator, it wouldn't be such a big deal. The fact that it can destroy your transmission if not caught and fixed right away is certainly a catastrophic failure in my book.


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[feetdry]

Well it might overheat the engine "just a smigg" if you don't get her shut down soon.

[speedlever]

Thanks for the explanation FineLine. Would the atmosphere near the coast (salt air) work similar to salt and water in the rust belt?

And is this the same way the MDX video showed the failure? It appeared to fail inside first and only came apart during the removal process.

Originally Posted by FineLine

Speed, for galvanic corrosion to occur the dissimilar metals need be in contact with an electrolye - a solution capable of conducting electrical current. In this case it would be a mixture of water and road salt, sodium and calcium chloride. The different electrical potentials of the metals isn't significant until the electrolyte is introduced. From the pictures I've seen it doesn't look like the corrosion is occurring from the coolant or transmission fluid being the electrolyte. It is external corrosion of the fitting washers, one is a cathode and the other is the anode with the result being an increase in the thickness of one of the washers. This forces the fitting assembly to move backwards out of the transmission heat exchanger which compromises the internal seal. At that point the two fluids can mix or if your lucky the entire fitting pops out and you lose both fluids before they mix and circulate through the engine and transmission. I think a periodic application of naval jelly on the washers would help considerably.

[speedlever]

Originally Posted by feetdry

Well it might overheat the engine "just a smigg" if you don't get her shut down soon.

Which could warp the head and cause other issues.

[frogbite]

Ok, i completely read this thread and even started one myself yesterday that I think I answered myself. One thing that is not clear to me is if it is reasonable to assume if you don't see any corrosion or rust around the fittings are you alright? I live in a warm climate in the middle of the state of Florida, so if I don't see any physical issues with the fittings should I be concerned?

I will probably still change out the radiator at 105k, but being at 95k now and seeing others hit this at 99k or earlier has me concerned. My truck is a 2007 and is also garage kept since I bought it in 2007.

[speedlever]

I think you're probably in good shape. Can you get some pics of your fittings?