E34 fluids and changing

[jhayregz]

Now just wondering, I found myself low on rad fluid. And I've notched up 2500kms in a week due to driving from a different province.

So if I was to change oil do I need BMW dealership oil or can I buy a synthetic kind.
And rad oil?
Automatic transmission oil?
etc.etc.

Thanks

[JhwShark]

How many miles and what year?? Is this the first time to check/add/replace fluids?

Try to use what you have been using. Radiator fluid is not oil and if you do not flush out old you do not want to add a different blend if possible. BMW has a special rad fluid in some applications.

I would stick with same format engine oil: if classic (non-synthetic) then add/change with classic....

For tranny use what the manual suggests...ATF (with some number format).

Jon

[jhayregz]

well thats the thing. im at the 3rd owner
last time fluids were changed were at 132000kms
now at 134xxxkms

i dont know what the previous owner had put in before

[mda185]

I have owned 2 E34 models over the past decade, 89 535i and 95 525iT with total of 400K miles. I run Mobile One 15W-50 synthetic in the summer and Castrol Syntec or Mobil One synthetic 10W-40 in the winter. The 15W-50 oil protects better than newer, thinner oil formulations that are made with fuel economy as the priority over engine life. Conventional wisdom says to use BMW factory anti freeze in the cooling system and you can't go wrong with this. You can however, use the newer formulations from Prestone and others as they are compatible with BMW requirements. This was not true 10 years ago. Red Line synthetic D4 ATF is one of the best automatic transmission fluids to use in the E34. Cheaper than the factory fluid and still a very high performance oil for automatic transmissions. I buy my Red Line from Summit Racing in one gallon jugs.

If you plan to keep your car a long time, the better synthetic oils are a very good investment.