Intermix Issue

[pdsells123]

I just bought a 2000 Millenium with 160K on the clock. (My 2nd Millenium and 3rd 996) The car has intermix issues as in oil in the coolant but no coolant in the water. The engine/trans are coming out next week but I am not sure how to clean the cooling system after I rebuild. Any suggestions? I suspect the oil cooler but will go all the way down with this much mileage...

[tonythetarga]

Depending on how thick the sludge is, cleaning may not work. I had a 99 996 with a known intermix that I bought and replaced the engine. I learned the coolant lines could not be cleaned and I replaced all of them. LOTS of hoses and about $1500 later. I had to replace the hard center pipes as they are thin aluminum and became perforated with pinholes from the cleaning dip. The rads survived the dip cleaning. If it still looks like coolant then you might be ok. If it’s lined with a brown sludge, it’s an issue.

[looneybin]

Jake Ruby says to run some Shout through it, it works better than anything
I guess if it’s good enough for clothes, it’s good enough for the cooling system

[BYprodriver]

Dawn is what's used to clean water fowl from oil spills in water.

[looneybin]

Originally Posted by BYprodriver

Dawn is what's used to clean water fowl from oil spills in water.

But you will never get it all out, and it will suds up and make air pockets

[pdsells123]

I mean't no coolant in the oil. The stuff is super thick and looks like a mocha shake. Another tech suggested pumping diluted (normal mix) of degreaser for a couple hours and than flush with warm water. They also suggested the the rads should be replaced as they will never get really clean. I will attach a pix next week when I get the engine out.

[Jeff Alton]

Cracked cylinder head?

Pull all coolant lines from the car for cleaning, radiator as well.

[pdsells123]

Engine out and apart. Bad oil cooler. I made a plate to bolt the cooler to and put soapy water in the coolant side. Guess what? Bubbles... I checked the heads over and they look good but will send to Hoffman to pressure check and do what needs to be done. Now that it is completely apart, I am impressed with the minimal wear for 160K miles. All the slides and pads are in good condition but there is minor bore scoring and minimal bearing wear. Since this is not the "keeper" car, I am thinking US Chrome for cylinder/block work, some new pistons/rings and go from there.

[pdsells123]

I am still trying to figure out how to "pump" whatever I decide to use as a cleaning agent. Something must be pumped through the whole system just to get rid of the milkshake. Should I use a sump pump submerged in a 5 gallon bucket with another 5 gal for the return? After the first 5 gallons start over with another clean batch? Then maybe a recirculating 3rd batch?

[Jeff Alton]

How far apart is the engine? If completely apart, pretty easy to clean the engine. As for the lines and radiators, remove from car and clean individually for best results.

Hopefully you did get lucky, an oil cooler failing internally is pretty rare. If you are concerned at all about the heads do a quick search you will find pics of where they crack, specifically the 2000 model for some reason is more prone that other years.