Oil cooler flush question.

[PhD_Polymath]

As some of you may know, my Disco had the unfortunate event of head gasket/ slipped liner (?) failure and made the oil look like a milkshake. I am completely overhauling the engine with flanged liners and most of the internal bits. My question is about the external oil cooler. As I want to ensure the new engine is free of gycol contamination, I turn to the Land Rover community for advice about how to flush the cooler of the creamy oil slurry that currently resides within. I don't really have the funds to replace it (I wish I could), but would love some insight. I thought about just running it and changing the oil at short intervals initially, but would prefer to have an idea of if the engine has coolant leaking into the oil after the rebuild (not flushing would yield a false positive, making me instantly pull all my hair out and end up committed to a mental health facility). Thanks!

 

[Binkie]

True flushing must be done with some sort of pump system, preferably separate from your engine, with seperate reservoir and plumbing, and filtration. Also, in order to flush properly, the flow must be high enough to develop turbulent flow at the tubing walls within the cooler. Generally, a flow significantly higher than normal would be good enough. A seperate pump system is not likely in your plans, though, so I would try to find something soluable both with water and oil somehow force it through. Perhaps some sort of solvent first, then lightweight oil, and call it a day? It you did this, you might still have some drops of glycol in there, but miniscule amounts.

 

[PhD_Polymath]

Thanks for the info. I am having a machine shop do a lot of work on the engine and will see if they or someone they know can properly flush the system with a pump. The turbulent flow is a good point. I see how a low rate could leave a lot of glycol behind.

 

[tacr2man]

In the past when doing this on other vehicles , I firstly flush with a degreasant, then use soapy water , and then clean water . Then use a high detergent engine flush oil . When doing engine blocks i have found diesel/flushing oil mix , then flushing oil , and changing the filters after a couple of short runs works ok . The end result was ok , as the vehicles worked oK for the owners , who would not have been able to afford a more expensive route . HTSH

 

[Binkie]

One other thing u can do, depending on the cooler design. If it is the single continuous tube bent round and round (NO end tanks), you can fire a foam projectile through the cooler using compressed air. This is done to clean new hydraulic hoses during assembly at more professional hose assembly shops. You can try to get this done at a shop for a minimal charge, or find a dense enough piece of foam and risk it yourself. DO NOT attemp this if there are end tanks, elbow or tee fittings within the cooler-you will never get the foam projectile out. If you loose the projectile, DO NOT use the cooler any more, it will either be plugged, or the projectile will end up in your engine somehow.