hello. I’m in the process of removing the radiator before I pull the engine and noticed quite a bit of mayo sludge in the top rad hose, so oil is obviously mixing with coolant somewhere. Problem is I have no way of telling if it’s a leaking oil cooler or HG issue. I’ll be replacing the HG as a matter of course (car has been parked for 15 years) but I’ve already drained all fluids so can’t pressure test. Is there any way to check the oil coolers once the radiator is removed from the car?

 

Pressure test of the oil cooler coil. The oil cooler circuit operates at a much higher pressure than the radiator thus why oil will blow into the coolant- 5 barg would be a sensible pressure but it may well show signs of leakage at a lower pressure.

 

 

Makes sure it is the coil they test at that pressure. The radiator itself can safely withstand 1 barg [15 psig] anything more and it will likely blow