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Join Date: Nov 2017
Location: Sioux Falls, SD
Re: Need Help w Overheating 327 '66
A couple of things to think about as a wrap up my overheating 327. In hindsight, it was relatively easy to flush the system with water. I initially was using different solutions that necessitated running to store and spending money. Simple water really took care of a lot of the problems and I was able to let it drain away instead of costly trips to the Hazardous Waste Recycling in my town.
When I figured out that flushing with water wasnít solving the problem by itself, my first thoughts should have been to take off the aluminum intake and inspect the passages of the heads. That would have saved a lot of time and cost only a few bucks for gaskets. The trick I posted earlier about using foil to protect from debris falling into the engine is a good one that Iíve been telling everyone about.
Itís best if you are working in warm temperatures, when working with your radiator. There were so many times that I was wet from my knees down or my elbows down because the water missed the bucket or I sprayed myself with the hose. In South Dakota, itís more tolerable to do so in May rather than January.
When draining water, I popped the bottom hose and always collected it. There were some pretty large chunks that came out and would not have fit through the petcock. The bottom hose was able to be pointed directly into a bucket under the front bumper. A 5 gallon pail didnít fit but a smaller 2-3 gallon I had from another project worked well, plus it had a lid. When I drained into the bucket, Iíd always inspect the water coming out. Did it look rusty, was it still green, were there chunks at the bottom? I inspected it every time I drained it.
The petcock was pretty damaged on my radiator, the only replacement I could find in my area had ďwingsĒ that didnít fit in the recessed area. I believe the recessed area of the radiator was to protect the petcock but it ended up making it more difficult for me to work with. I used a Dremel to trim the wings to fit into the recessed spot.
Initially I had purchased a new radiator, thinking that was the problem. Once I established that it wasnít, I quickly put the old radiator back in. The old radiator was still in working order and if there were going to be particles passing through the system, I wanted them going through the old radiator. As it now turns out, the old radiator is working very well and looks better with my old school build than a bright shiny new one.
Another idea I had was to use a small scope to see into the radiator to inspect how the tops of the tubes look. Tubes can probably plug anywhere down their entire length, however I hypothesised that the top tank would have more blockages or chunks than the bottom since the water travels top down. Big deposits wouldnít make it to the bottom tank when I flushed the system. So after It appeared to be clear, I pulled the radiator and flushed it upside down. So much more stuff came out and the radiator cooled even better.
Radiators are made of very malleable material, handle with care. Itís extremely easy to bend fins or bust off petcocks. Also leave the thermostat out of the equation, replace it after everything is done, it saves you a lot of time. It doesnít hurt to pick up about 5 extra gaskets for it anyway, they are cheap.
One product that I liked was the Blue Devil coolant flush. Every time I thought I was finally done, Iíd run a bottle of that stuff through it, follow the directions, and drain out more murky water.
And finally, the biggest solution to this problem was this forum. The posters on here are awesome and provided me with the tips Iíve listed above. While I might say I figured them out, they were really provided from a lot of other people who solved this problem before me.
1966 Malibu 327 200-4r