AO Platinum Member
Join Date: Feb 2002
Location: The land that Time forgot
My conclusion in that thread is that the radiator's mounting is causing the radiatore to fracture (i.e. physical stress or flexing). The pressure inside the system would most likely burst a hose connection or even a hose before the radiator itself let go.
There's a simple test to check for pressure in the system (open the bleed screw - cold system - and see if any air comes out). No air means no internal problem.
A faulty water pump would cause the engine to just overheat.. not desirable but it's not likely to burst the rad. Similarly a dodgy thermostat would allow the engine to run too cool or too hot... not cause a pressure build-up.
In any case, I understand that your lad has fitted a new expansion tank (aka "radiator") cap and a new thermostat.... so those are brand new. The only way a cap would not help is if there is air trapped in the radiator (it has no means to get out). Any gas in the block would find it's way out of the header tank (probably pushing coolant out with it). You don't have coolant loss, or stains around the cap AFAIK so that suggests it's all good in there.
If there's no air in the system.. then it must be an external problem rather than an internal one...? Engine has been rebuilt loads of times and it only needs one of those rebuilds to have been any good to have sorted the problem out. It's unlikely that x number of garages could not have fixed a dodgy head gasket correctly. It's also unlikely that you have a cracked or porous component .. so many replacement parts and again only one needs to be good to have fixed the problem.
Take the bumper off and look at the rad' mounting in clear daylight. It has 2 bayonet lugs which sit in rubber cups/bushes that themselves locate into the bottom radiator mount. Put the bushes in the mount holes first and then slide the rad' lugs into the bushes.
The top of the rad is fixed to the front valance by self-tapping screws which fit through rubber pads (very thick rubber washers). The holes should all line up and the radiatore should not be under tension. It just sits flush against a metal panel (resting on the bushes) and the screw goes through it. It's semi-rigidly mounted.
Also if you have air/con' plumbing bolted to the rad make sure that it doesn't put pressure on the radiator. If you're tightening it up under tension, then something isn't right. It should just line up and bolt to holes in the radiator side-flanges.
Look on ePer to get a diagram of what it should all look like..
No bullets for Chaingun..