21-06-2012, 10:51 PM
I've been reading recently on the forums, there seems to be more and more people doing it, either if you've snapped the heater matrix hose connections, which is stupidly easy to do as they get brittle from the heat from the exhaust manifold, or because the heater matrix has failed.
DON'T DO IT!!!
The cooling system is finely balanced on these engines, it's quite heavily engineered to do it's job. If you shove a bit of pipe between the inlet and the outlet, you'll end up passing the almost the entire cooling system flow through the pipes off the head since this is the easiest route, meaning you lose approximately 2/3rds of your radiator flow to just pumping it through a closed loop where no cooling will take place.
The other way is to block it off - this causes hot spots in the cylinder head, since there's an outlet to the matrix on the back of the head in one corner, this means that the corner doesn't receive much water flow at all, causing it to locally get very hot in that one spot.
Just replace the heater matrix as soon as possible!
The XUD9s are VERY sensitive to heat - it's their one downfall that affects their longevity, if you overheat them, they just destroy themselves very quickly - the gasket goes, you fill the head with air, then you just massively overheat the cylinder head and then warp it to high heaven. If you see the temperature gauge go above around 90*C - lift off and leave it cool down, you WILL eventually pop the head gasket if you keep using the power above there.
Just a quick warning really, unless you like replacing heads/gaskets - keep the matrix in. The cooling systems are much more complicated than they first look!
DON'T DO IT!!!
The cooling system is finely balanced on these engines, it's quite heavily engineered to do it's job. If you shove a bit of pipe between the inlet and the outlet, you'll end up passing the almost the entire cooling system flow through the pipes off the head since this is the easiest route, meaning you lose approximately 2/3rds of your radiator flow to just pumping it through a closed loop where no cooling will take place.
The other way is to block it off - this causes hot spots in the cylinder head, since there's an outlet to the matrix on the back of the head in one corner, this means that the corner doesn't receive much water flow at all, causing it to locally get very hot in that one spot.
Just replace the heater matrix as soon as possible!
The XUD9s are VERY sensitive to heat - it's their one downfall that affects their longevity, if you overheat them, they just destroy themselves very quickly - the gasket goes, you fill the head with air, then you just massively overheat the cylinder head and then warp it to high heaven. If you see the temperature gauge go above around 90*C - lift off and leave it cool down, you WILL eventually pop the head gasket if you keep using the power above there.
Just a quick warning really, unless you like replacing heads/gaskets - keep the matrix in. The cooling systems are much more complicated than they first look!
