[oab_au]

Giday Keith, the EGR can cause the rough running but I can't see it causing the rise in temp.
The EGR starts working when the engine is up to temp and the throttle is at cruise position. If you push the throttle down the EGR closes. This seems to work in with the way the trouble comes on for you.

There is another component in the system the BPT valve, this looks at the exhaust pressure and varies the amount of exhaust gas that the EGR valve passes. If this valve is inoperative the amount of gas fed into the inlet will always be at maximum, to affect the running at cruise. This can also cause the O2 sensor to read an abnormal signal that it can't relate to any other component, so it gives a code.

I can't see this causing the way the temp changes. The engine can't produce a higher temp when the amount of burnable gas in reduced by the EGR, the temp has to be reduced in the combustion chamber, hence in the water also.

Harvey.