I am starting a new thread after the many twists and turns of identifying the root cause of a creeping overheat condition. The car has both a sludge/obstruction issue in the cooling system and there is substantial damage in the thermostatic switch tee due to electrolysis. The journey to this point was described in this thread:
Last entry and identification of the issues
I started to pull the radiator out last night and didn’t get far before I found what the issue was - actually two issues:
- The main overheating root cause is a complete blockage in the hose from the header tank to the thermostatic switch tee. Michael - you were right!
Look at the part, it’s a disaster:
The hose to the header tank was also blocked:
There is green sludge present in the system. It looks like there was an intermixing of two coolant types that precipitated the sludge. I think heating the engine accelerated this. I had not touched the radiator before this issue started occurring so the PO must have done this before he sold me the car.
I think the location of the sludge is at the coldest area of the coolant. My hope is the engine will be less affected but that will have to wait until the water pump is pulled and the engine is flushed.
- The second issue is that during the restoration for this car, the issue of possible electrolysis and subsequent damage to the radiator and other parts were not considered. If you look at the tee along with the replacement part I had recently purchased (I had planned to replace it during the radiator install), you can see the horrible state of this unit along with the lower radiator outlet. Both show severe erosion and would have failed/leaked soon.
At this point, it is clear that a major amount of redress and flush is needed.
I think this thread has arrived at the conclusion which is the identification of the root overheating issue as well as recognizing that the car has electrolysis part erosion that requires corrective work. I will start another thread on the journey to get this car back on the road. I will add the link to this thread when I start it within a few days.
Thanks to all for your invaluable input that has helped get this issue identified. I think it may help others seeing this kind of creeping overheat condition.
I think looking back, the easiest way to see if this is the issue is to pull the thermostatic tee out and inspect for sludge and obstructions.
I will list the areas that will be addressed and (hopefully) fully fixed in the next post in 1-2 days. Comments and suggestions welcome.