I just need a straight answer. After reading multiple threads about the topic of coolants, I cant seem to get a straight answer. I am concerned about the coolant I have been using, which is dexcool. Not the 50/50 stuff, just the orange coolant from autozone. Is this bad? Some say yes and some no. What should I do since I just changed the thermostat and filled up with dex?

I own a 2001 Disco II SE7
180k

 

drain and flush your system, replace with 50/50 regular coolant. the major problem with dexcool is once it mixed with air it start blocking everything up.

 

Got it! Thanks for the reply.

 

Drain and flush. Use 50/50

 

Pix of sludge buildup caused from Dexcool in a non-perfect not-the-engineering-test bench world -

Also, try to always use distilled water if adding just water, final flush out, or mixing your own coolant. City water has some calcium in it, certainly if the source is deep wells. Country water untreated from wells has even more calcium in it and will do bad things to your radiator.

 

I've been using peak anti-freeze in mine. It seems to run cooler with it. Rarely did it get above 203F in the summer, even when idle, a/c on, and 100F+ outside. I did 2 flushes, and will likely do a 3rd before winter really hits us. Gotta make sure to get all the dexcool out, and to make sure the coolant is 50/50 for sure. I go into the mountains with it and it gets -17F and I would hate to blow a freeze plug.

 

I've been going through the same issue; as a member of this board (off and on, my poor disco sat in storage for 4 years) since '08 I have seen varying expert opinions on what should go into our trucks.

My philosophy has become this: what does the manual say, and what choices do I have within manufacturer's spec.

I've done some research this morning, and here's my conclusion:

For coolant the manual specifies OAT (organic acid technology). Use whatever you want, as long as it is OAT coolant.

OAT is designed to interact with metal when needed to remove deposits. IAT plates metal, and then breaks down over time. Who knows what difference that makes within our trucks. Maybe nothing, maybe something.

Regular Peak has phosphates, making it an IAT (inorganic) coolant. Global Lifetime is Peak's OAT coolant, so according to the manual that's what we should use.

I'm going to flush my DEXCOOL, put in Peak global lifetime and flush every two years.

Reading material:

DEXCOOL pretty much sucks after 2 years.

Dex-cool Contamination

Gates coolant info

http://www.gates.com/downloads/Gates...h_Bulletin.pdf

Standard Peak coolant MSDS, showing phosphates.

http://www.peakauto.com/pdf/msds-pea...ze_coolant.pdf

Peak FAQ. Describes Peak Global Lifetime as their OAT coolant.
PEAK FAQ

Good luck,

Josh