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The TA has had a slight overheating issue and I couldn't figure it out. It would take forever to warm up and once it did it didnt want to cool down. I decided to install an electric water pump and started removing everything today. After removing the old water pump I found this interesting bit of corrosion which might explain the funky temp issues.
The pitting from corrosion was so bad I had an 1/8 inch missing between the 2 channels and it occurred on both sides of the water pump, just less so on the other side.
I thought it was interesting, has anybody experienced this before?
Likely the result of some galvanic corrosion. Either the water pump is "leaking" voltage (poor/no ground) and is essentially electrolyzing the metal right off the pump housing. Could be use of incorrect coolant. How does the mating surface on the block look?
I saw this once on a 4.0 L Jeep thermostat housing, there was literally no gasket material between the housing and the head. The coolant was very peculiar in color and suggested there may have been some "mixing" which depending on the mixed varieties will destroy materials or plug passageways.
I’ve seen it before in engines that had used just water for a long time or sat with just water in the block.
Water is incredibly destructive, especially when left alone.
out here in the refineries i work in, they deal will all sorts of chemicals. sulfuric acid, benzene, hydrogen sulfide etc, etc. the single most damaging chemical to the equipment - water.
water will absolutly obliterate any thing if given a little bit of pressure and heat cycles. its quite amazing.
I’ve seen it before in engines that had used just water for a long time or sat with just water in the block.
Water is incredibly destructive, especially when left alone.
Absolutely. What is THE most destructuve force regarding natural disasters.
Originally Posted by LT1FirebirdSLP
Likely the result of some galvanic corrosion. Either the water pump is "leaking" voltage (poor/no ground) and is essentially electrolyzing the metal right off the pump housing. Could be use of incorrect coolant. How does the mating surface on the block look?
Aged coolant can carry voltage as well. OP, if this is the case, you need to check out the inside of your radiator to ensure it too has not started corroding. I’d suggest flushing the **** out of your system. Were you using regular water or distilled?
Thanks for the input guys, I appreciate it. According to our PHD'd engineer who handles our metallurgical testing needs, the term for this type of corrosion with aluminum surfaces is "Crevice Corrosion". The aluminum is unable to create the oxides needed to protect its surface so it corrodes whether in the presence of chemicals or not. This is particularly eventful in aluminum surfaces where gaskets are used for prolonged periods of time with a high clamp force that creates small crevices beneath the seals.
The coolant being used was a GM specified coolant that was 15 years old. I have drained the entire system from the radiator and the block but will flush it twice once I finish putting the electric water pump on. I've been on a guys trip in Moab with my father and son since my post, but Ill have it squared away when i get back.
As for the block, I haven't removed the gasket material from the block yet and I am worried that rust might have occurred there as well. I'll know by this weekend I think.
03-06-2019 | 07:38 PM
Overheating Issue with Interesting Find 
