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

Hello guys,

I would like to hear your opinion on using O.A.T. coolant. Just a few facts: I have a DII V8 2001 160t km, with changed water pump and new head gaskets at 120t km service - this is two years ago. The mechanic who did the job put a new coolant in. This was green in colour and since LR recommends a pink O.A.T. coolant I was a little bit worried. The mechanic told me that it is safe for the car and I shouldn't worry about it.

Before the start of the summer season, this is like two months ago, I changed the coolant again. I have read a lot of posts regarding the coolant. As I learned, there are two groups of people - one saying go for the O.A.T., the other one saying O.A.T. is a piece of crap. I went for O.A.T. as recommended by LR. I flushed the system first using a Nulon coolant flush, drained everything, flushed a few times with pure water, ran the engine, flushed again, until a perfectly clear water came as the last drain.

Then I used 6liters of nulon O.A.T. concentrated coolant and added 3.5 litres of demineralised water. This means a mixture of 6l O.A.T., 3.5l demineralised water and 3.5l of soft tap water in the cooling system. Now, after two months and 2000km driving, I have 3 coolant leaks. The first is around the water pump, and the other two on the left side of the engine around the head gaskets. I attached a few pictures. I am pretty sure that the engine didn't overheat during the time and also I checked the temperature sensor with a scanning tool if it works. No problem here. The leaks seem to be external only - I checked cylindres' compression - around 170psi each cylinder.

Please, is there something wrong what could cause the three leaks? Three leaks which appeared simultaneously? They were not there before I changed the coolant, I am sure about it. Is there something wrong with O.A.T.? Too reactive? Should I switch to a different coolant? Note again, the water pump and head gaskets were changed 2 years ago (40t km back) and I didn't have a single problem with the green coolant.

Thank you for you help and apologise for this long post
Cheers
Jiri



pic1.jpg

pic2.jpg

pic3.jpg

Originally Posted by BigJon

OAT is very "thin" and it will leak where ordinary green coolant won't. As a first step I would go back to the green stuff and see if it cures the leaks. As others have noted, Rover V8s lasted for years and years on the ordinary stuff.

There is alot more aluminium in the cooling systems of the later model Landys,after reading HOW the OAT works in other posts,Im more than happy to keep using it.
Andrew