2.5 Td Cylinder Head Refitting

[noz]

I finally found the time to put the head back on to the silver 2.5 last weekend. I've used it all week to get to work and it's fine apart from a pin hole which has developed in the big radiator. The radiator is only 18 months old so it's not corrosion. I found that the plastic air vent on the hose coming from the intercooler was rubbing against the fins and wore a hole right through to the water. I tried to solder as best I could but the heat exchange surface seems to be coated in some sort of placstic film. Anyway, I repaired as much as I could and sealed the remainder up with radweld.

The air vent should have been mounted in the rubber housing which is moulded into the top radiator hose to keep it away from the radiator. It is now......

This was the second time the head had been off. I should have spotted the erosion between cylinders the first time around. An expensive mistake and one that won't be repeated.

I'm not convinced the heads on the 2.5's are particularly weak as some have suggested. I think it's more to do with the extra half radiator mounted in front of the main radiator. In addition both the oil cooler and intercooler both dump their heat into the cooling system. This might be just acceptable when the system is brand new but as the system corrodes naturally, the reduced heat transfer means the heat cannot be dissipated as fast and the head cooks under heavy load. After suffering this maltreatment a couple of times the head duly gives in.

These things are sent to try us.

Cheers

noz

[Peter.N.]

Hi Noz

I don't envy you that job this time of the year in Scotland, cold and dark. I have very succesfully repaired holes in radiators by just bunging a lump of ordinary linseed oil putty in the hole, it goes off like concrete. Looking at the design of the 2.5 cooling system, it does seem to be asking rather a lot of the radiator to get rid of all that heat.

Peter.N.