Anyone know about Nikasil BMW motors?

[vega]

How much of a problem did the UK have with the V8 short block?

I know there were quite a few engine failures in the states.

[andyf]

im getitng an V8 as one of tmy three optiosn

[Jezz_S13]

don't know the full details, but ther were bad weren't they, if it's the block I was thinking about.

I was talking about getting a 735i (straight 6) a while a go to a bloke quite knowledgeable about BM's and he told me to avoid the 740 and newer 730's with the V8's.

[vega]

OK, alcohol got the better of you again then mate :rolleyes:

That was just the kind of information I was after, cheers, piss 'ed :D :D

[vega]

Apparantly, the bores are plated, not lined, with Nikasil, which is Nickel ans Silicone. This was a weight saving and money saving feature. It wasn't new technology though, as porsche have used the idea, and all of BMW motorcycles used it from 1981.

But in the states, these new M60 V8 motors started to break town. Lumpy idle to start with, then total failure. BMW found the motor was failing the leakdown test, and further investigation showed it to be down to worn bores. They started replacing them for new, but again fitting these nikasil blocks.

The cause was apparantly down to high sulpher content fuels, very common in the US. In the UK though, Low sulpher fuel was very much normal from '93, so I don't know how badly affected we were. I can't find many reports of problems over here.

BMW extended the warranty to 4 years or 100,000 miles, and then started to replace the blocks for Alusil ones. They also tried to retard the timing and replace the thermostat to get the engine to run hotter, as many of the motorbikes were air cooled.

Basically, my dad is looking at a 530i, and it is lovely :) 75000 miles, sounds nice and drives good. I had a drive in it during the test drive and it can't be faulted. Doubts are being cast because of this though, real bummer. He has all but agreed to buy it from the dealer now too :(

[Chris]

nikasil bores were used extensively in motocross bikes and were notoriously fragile ( but i stopped riding 10 years ago so could be out of touch )

jaguar adopted plated bores but had a 50% reject rating on the production line ( due to porosity )

land rover are also suffering engine durability probs at the mo

[vega]

Oh well, looks like he's gonna buy it anyway :)

[Paul_S13]

I think it was a few years ago that both the V8 and the straight 6 lumps had trouble, apparently up north they had a batch of high sulpher petrol that killed many a BM engine and they did offer free rebuilds for awhile.

[vega]

It'll be ok so long as only quality fuel is used though won't it?