Thread: What is wrong with using O.A.T. coolant?

I have the same question.
My mechanic ( a prominant Sydney Company ) said change to the green stuff. I could not see why it needed to be changed when the vehicle was made for and delivered with this OAT coolant.
When my head gasget was changed the work shop that did that ignored my request and put green stuff in it. Prior to this my water pump leaked. When the green stuff was put in it stopped leaking ( only leaked when very cold and turned off ).
So after 40k I changed back to OAT, since then the water pump started to leak when the engine was turned off and the temp got down to about 0.
I got a new water pump, it leaked more than the old one, I got another water pump, it didn't leak for 10k then it has started to leak. My current mechanic tells me that the surface tension of the OAT is far less than the green stuff which is also far less than water so it leaks but it still ****es me off.
So what is the solution???

Thank you guys for your comments. I am happy to try some experiments I am now thinking to use a different coolant, either Castrol or Nulon green hybrid, and see what will happen. Both contain silicates, though in different rates.

Any recommendations which coolant to go for? What do you guys use? How often do you change the coolant? More often than once in 2 years?

Cheers
Jiri

I have been using the Castrol corrosion inhibitor for the last 15 years, no problems so far. Before that I used SQ36.

this is precisely why i wont use OAT, coolant leaks. end of story

It really depends on the original coolant spec. OAT cannot be used in a standard green coolant spec'd vehicle. It will eventually affect the rubber components it come into contact with including head gaskets.

Also, where originally OAT is spec'd and green has been used, there will be pockets of corrosion or scale somewhere in the water galleries especially around gasket joints, out of view.
The re addition of OAT will start to attack this corrosion and then protect the affected area. Leaks will eventually follow.

OAT is a technical progression, the bad wrap is either thru misuse, misinterpretation, and misinformation.

Green coolants, I have found the Nulon non glycol Extracool excellent. Add to this some Redline Waterwetter and its good. However it still requires changing every year.

CAT ELC is supposedly from the same tap as LR OAT but has additional SCA's added for the heavy duty truck and machinery use. Anti cavitation additive to protect ignition position of wet liners and waterpumps, flow and contact additives to reduce temperature thinning and maintain a high heat transfer co efficient plus some others extending life and anticorrosion properties.

Both types will suffer if the cooling system has air leaks, however some brands of OAT will suffer badly from exposure to air, namely GM Dexcool products, however after millions of dollars of warranty claims and litigation, GM now say they have modified the chemistry.

Just used what is spec'd and experiment with different brands of the correct type.

Cheers

Andrew

Good Thread is this,

I was planning on changing from Green Nulon which has been in the car since I bought it 3 yrs ago to the red Nulon with OAT. But now I'll just stick with the green coolant.

I can understand the reason for not changing from an established green to a new red OAT as posted by LOVEMYRANGIE and for maintaining a discipline of changing regularly.

I'll stop thinking about when to change, and just get on with enjoying my D2.

Thanks

Just to make you feel better my 3.9 drools from the ends of heads also and I use Nulon Longlife green and have for 11years.

It is a characteristic of V8s .

Mine has got worse since my 18KK towing the camper in up to 45C without the gauge ever moving from just below 1/2 and now uses about 5Ml of water per 1000Ks. I think there is something in the comment that thered stuff is more easily seen.

I think the engines can get up to 100C or so without showing on the gauge and The loosening of the head bolts lets some water/coolant out.
If you are not losing significant water just put it down to another Land Rover quirk.
Regards Philip A

can i just say from a reasonably long background in auto parts, this is not just a rover quirk. they were simply one of the many european manufacturers that weren't scared to go a little ahead of the pack and try something new and interesting.
as usual with someone sticking there heads out a little, they are the first to be chopped off in the bad times.