I have noted many instances of radiators being replaced purely because of a split/cracked top tank.
This was a recent problem which resulted in my SVX letting me, or in to be exact my wife down, for the first time in eight years of daily motoring.
Several radiator specialists offered a new OEM radiator, a replacement custom made alloy top tank or a new custom made alloy radiator. All very veryexpensive options.
I went to a plastic repair specialist and the tank was welded for the huge sum of NZ$20,00. The fracture was welded closed, overlaid with extra material, then reinforced with fiberglass tape impregnated with weld.
The crack of about five inches in length, was across the internal angle formed at the front of the tank, where a flange is formed to provide a flat surface for crimping to the the metal core. This is an obvious weak point, subject to vibration stresses, originating from the flexibly mounted engine and passed via the top hose. The area is now reinforced and I beieve better than when new.
The tank could have been welded while in the car, but I chose to remove the radiator as the traveling distance involved, could have meant overheating the engine.
When the car overheated while my wife was driving, it would appear that the ECU shut things down. She had noticed heat and had observed the temperature gauge in the red, just before this happened. She said it was if the ignition had been turned off and there was no indication of anything tightening up. I have not seen this feature documented and wonder if anyone can confirm it as a being safety measure?
P.S. ---- N.B. I am advised that the tank is of a Nylon matereial and a special plastic welding rod is used together with a special hot air gun. The result is a fused joint much as with a metal weld. This is no way a stick on fix and is permanent.
I reason that the crack has in fact relieved what was a previous stress point in the tank by opening up. Therefore the repair should correct an existing problem. Special attemntion shoiuld be paid in respect of the flexibility of the top readiator hose, for obvious reasons.