Originally Posted by Bodi
Does the EGR plug from sand/castings first and cause the oil Cooler to starve of coolant or does the Oil Cooler plug first and cause the EGR to starve of coolant?
Or am I miss understanding the entire EGR/Oil Cooler concerns??
As the coolant goes thru the motor, it goes thru the oil cooler before it goes to the egr cooler. The oil cooler is a has coolant passages running thru it to cool the oil. The coolant passages in the oil cooler are very small compared to the egr cooler, these coolant passages in the oil cooler get clogged up from casting sand and silicate fallout and block up the the very small coolant passages. Once oil cooler coolant passages clog up, you don't get good (if any) coolant flow to the egr cooler. When there is no coolant getting to the egr cooler, the super hot exhaust gasses (800*+) damage the passages in the egr cooler.
Also when the oil cooler gets blocked up, it doesn't cool the oil down either. This will cause the motor to have a meltdown of the plastic internals of the oil filter stand tube which will destroy the motor.
This is why it is so important to monitor ECT and EOT, even if you do the egr cooler delete.