Nikasil and oil and temperature

This isn't a real fix, the tried something similar on the early V8s too. It robbed a bit of power there, not heard ofit being done to M52s though.

You should find plenty of oil rated to API SG or SL combined with CF4 or CI4 which are superior and newer ratings. These will usually have an SAE viscosity of 15w/40 for heavy duty use even in very hot climates. The CF, CG4 CH4 and all C ratings are heavy duty, high detergent diesel ratings but can be combined with petrol ratings to produce what are called 'multifleet' oils suitable for both petrol and diesel engines. These are superior oils to petrol only type as long as the viscosity is suitable for the application.

Huw

The Thermostat and ECU reprogramming were both part of a service campaign (12 09 94 - 4132) as an early attempt to head off the sulfur corrosion of the nikasil liners. I do not believe that either of these modifications were successful if the car was run with high sulpher fuel it still wore the linings. In that campaign the 85 degree thermostat was replaced with a 95 degree one.

I have a 94 540i which originally had the nikasil block. It was subsequently changed to an alusil one by BMWNA. Interestingly, the thermostat in mine was still the higher temp one and the ECU was not reprogrammed back to original after the block swap.

As a part of a recent major service inspection (which I performed) I replaced the higher temp thermostat with a Wahler 85 degree one,a s well as replacing the original hard plastic thermostat housing with an aluminum aftermarket one.

Are you sure it's a nikasil block? I didn't think any of the small sixes had them.

Europe had all aluminum blocks in the early '90s (I believe with the M50TU) while US had iron or sleeved blocks until the M52 in '98. They had a big problem with the nikasil blocks in the UK.

FloydR

BMW South Africa confirmed that my car has an Aluminium/Nikasil block. BMW donated a number of these vehicles to the South African Police way back in

1995/1996 and ran them each with a 200,000 km service plan. Even though the Police destroyed most of them in accidents, a few survived that and made 200,000km without any problems (according to BMW).

In my view 2.8 is hardly a small six, but you are right, the smaller 2.5 and

2.0 sixes were not brought to SA with Nikasil. Only the 2.8 was sold here and only for six months or so after which cast iron blocks were reintroduced.

I am not familiar with what BMW SA did regarding the Nikasil V8s.

Getting back to the oil issue. Should I just top-up with an oil recommended for diesel engines?

Kind regards MW de Jager

Not specifically. You can use a dual rated oil though. That is, one which has an S rating for petrol as well as a C for diesel.

Huw

Yes, they most definitely did, but not in the US where they had cast iron blocks.