Tuesday, Oct 11, 2011 at 11:34
from what you describe, it sounds like your rad core is either internally, or externally blocked.
Works fine in most conditions, but put that bit of extra load on it, and it cant cope and exchange the heat created.
First thing to do is to make sure the air con condensor is not blocked full of grasshoppers/ leaves etc, and then
check between that and your rad core, often the bit between the two can become full of debrits.
Even a garden hose to back flush from the engine side forwrads thru the core can move a bit of stuff.
If your water pump is not leaking, nor the shaft wobbly, leave it be for now.
Basic
check of the rad cap will show if its allowing the system to stay correctly pressurised, thus increasing the boiling point of the system, however if the engine is creating heat, and the cooling system is not dealing with that heat, then look for the bits that exchange that heat.
I am surprised that they didnt do a basic co
test of the cooling system, that will show any sign of combustion gasses entering the cooling system, but often when this happens, other symptoms occour that you have not mentioned yet.
Other things to observe are the workings of the fan viscous hub, and ensure the fan shrouds are correctly fitted, and not allowing air to be dragged in from the wrong side of the radiator, thus loosing cooling efficiency.
Its called a cooling system, as there are a few parts that make it a whole, and one or more with a fault can cause issues.
When I had my garage, with what you describe, blockage of the rad is the first thing I would have looked at, along with cap operation, and a co
test.
Even a good looking radiator, if its 20 or 15% blocked internally, can cause the symptoms you describe.
Worth the coin to remove rad, and remove tanks, and do a proper cleaning job.
Hope this helps
Trains
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