Cars / e32 / Engine / The BMW Nikasil Issue

The BMW Nikasil Issue

Article by: Simon Worby

Article applies to: E31, E32, E34, E36, and E38 models with aluminum blocks most notably the following: 320i, 323i, 328i, 520i, 523i, 528i, 530i, 540i, 728i, 730i, 740i(l), 840i

What is the “Nikasil issue”?

The “Nikasil issue” is a serious problem that affects all BMW motor cars with engine blocks with “Nikasil” liners in their alloy block when high sulphur fuel has been used. This is 8-cylinder models with the M60 engine made from approximately 1993 to 1996, and 6-cylinder models with the M52 engine made between 1995 and 1998 (note M52 Nikasil engine never went to the USA). The “Nikasil issue” is extremely serious as the final result is a non-functioning engine. The material “Nikasil” is also known as “Galnikal”. “Nikasil” is a very hard dispersion layer of galvanically (electrolytically) applied Nickel applied to the soft alloy bores to prevent wear. If this hard layer is damaged, excessive bore wear occurs rapidly.


Above: Examples of pitting and damage to the nikasil lined cylinder walls.
Thanks to and photos by: Stephen Bottcher –

What causes the “Nikasil issue”?

In short, high sulfur fuel. Contrary to popular belief, the “Nikasil issue” does not only affect the USA. It is potentially in existence in all countries, but is a particular problem in the UK and the US. It would appear that Nikasil lined blocks were not tested with fuels that had a high sulfur content, which was unfortunate because the chemical reaction between the sulfur in the fuel and the nickel lining in the block caused damage to the hard nickel lining. Once the lining is damaged, excessive bore wear of the soft underlying alloy occurs very quickly. Some Nikasil engines have failed in as little as 30,000 miles.

Fuel high in sulfur was imported into the UK and (apparently in very small amounts only) into continental Europe. The problems occurred first with cheap (supermarket) fuel in the north west of the UK, although in time the whole of the UK was affected – and it was no longer just supermarket petrol that was causing problems. Having said which a vehicle run only on good quality fuel which was low in sulfur would not have problems, but there was no way the consumer could know which fuel to buy. There do appear to be quite a few Nikasil engined vehicles which, either through luck in the fuel used or some other mysterious reason, appear to be absolutely fine even after very high mileages.

Continental Europe (through essentially not getting high sulfur fuel) appears to be largely unaffected by the Nikasil problem: it would appear that they did not suffer from imports of high sulfur fuel. I have not heard of any problems with Nikasil cars on the Continent, nor have I found any reference to any difficulties.

Is it BMW’s fault?

Yes and no. The basic problem is with the low quality fuel. We can only assume that BMW did not discover the problem in their testing because they used only good fuel; had they known about the potential issue, we can only hope they would not have released the engines! Sulfur can be, and should be, extracted from fuel before it is used, however this is a costly business. Fuel from South America is high in sulfur and was cheap to buy. But the extraction of sulfur is dear, so it simply didn’t happen. So it is the oil companies’ fault. Or should BMW have been more thorough in their testing?

Whatever, this issue has cost BMW quite a lot of money. The really weird thing is that they released a new Nikasil engine (the M52) after they knew about the Nikasil issue. It would appear that at that time they also thought it was a US-only issue, because the Americans got an all-iron version of the M52 engine, whilst in Europe we got a Nikasil one. As the issue has proved to be far from “just a US issue”, this risky 6-cylinder decision has cost them rather a lot of money in addition to the money the 8-cylinder engine problem was already costing them.

Or is Nikasil the problem? Well, not really. Nikasil has been used for a long time and is still used by BMW in their motorcycle engines – without problems. As BMW themselves say, “[…] this process was used for some years in BMW motorcycle engines before being introduced in the V-8 engine, so it’s not an untried technology – just an advanced one.” In fact other manufacturers used Nikasil and some still do – with varying degrees of success. Porsche appear not to have any problems with their Nikasil lined 4-cylinder or flat-6 engines, but there are reports of problems similar to that with the BMW both in Audi’s and in Jaguar’s V8 Nikasil engines.

In summary, I don’t think it is a simple enough problem to be able to apportion blame easily. I think it is fair to say that BMW did make some mistakes, and perhaps should and could have reacted more quickly. But the basic problem was caused by the quality of the fuel supplied by the oil companies over which BMW had (and have) no control. Arguably the oil companies who supplied the poor fuel have cost BMW dear and have badly damaged their reputation, and there is nothing they can do about it. I bet BMW wish they could just pass on the complaints and costs to the oil giants…

Undoubtedly BMW did make mistakes in dealing with the Nikasil issue, but I do not think it fair to blame them for the root cause of the problem.

How do I tell whether the car I am looking at might be affected?

Only the M60 and the European M52 are affected.

The M60 is easy – it was fitted to all the E34 530i and 540i V8 cars. It was not fitted to the earlier E28 5-series or the later E39 5-series. Also the early E34 3.0 cars (pre-1991) were M30 6-cylinder cars and were not affected.

The M52 is not as easy. The E36s (3-series), E34s (5-series) and E39 (5-series) are affected. E30s, E46s, E28s are not. But not all the 6-cylinder cars are affected either. The early ones had the M50 (no VANOS) engine, and late ones had the M54 (double VANOS) motor. It is only the single VANOS M52 units that were affected (and then not even all of them). The effect of VANOS is to lower the revs at which peak torque is produced. On the M50, peak torque is produced at 4,700 rpm (2.0 and 2.5 litre). On the M52, maximum torque is produced at 4,200 rpm (2.0 litre) or 3,950 rpm (2.5 and 2.8 litre). On the M54, peak torque is produced at 3,500 rpm (2.0, 2.5 and 2.8 litre). Look at the peak torque figures in the Owner’s Handbook and your question is answered.

Once one has established that the engine is an M52, the next stage is to work out whether it has Nikasil liners or not. Steel liners were introduced into production at Week 10 in 1998, i.e. March 1998. Cars built before then will have Nikasil liners; but that is not the same thing as saying that cars sold after then will have steel liners – cars can sit around for a while, and it is the build date that is critical, not the date on which the vehicle is put into service. Contrary to certain information, the engine code change from “S6 3” to “S6 4” did not coincide with the move to steel liners and therefore not all “S6 3” cars are Nikasil. Whilst it is probably safe to assume that any car sold during 1999 or later is safe from the Nikasil issue, my advice (to be on the safe side) has to be to be very wary of any M52 and check the block material with BMW before buying it.

Also affected are the 7-series with the M52 and M60 engines, and the 8-series with the M60 engine. The Z8 with the M52 engine is not affected as all these cars received the “American” iron block (because they were built in the USA).

Will the problem develop in my engine now?

Theoretically a new Nikasil engine used solely with Ultra Low Sulfur (ULS) fuel (as is now the norm in the UK) would present no problems at all. Had ULS been the norm in 1993, it is perfectly fair to assume that we would never have had the Nikasil issue.

However, the problem is that if the engine has already been affected, the all-important protective wall in the cylinder will have been damaged. The problem will therefore worsen, albeit perhaps marginally more slowly.

The long and short of it is that this issue is likely to rear its ugly head at some point or other in the vast majority of Nikasil block equipped vehicles in the UK. This is information that is well worthwhile knowing.

What are the symptoms of cylinder bore wear?

Initially uneven idle caused by “leak down”, i.e. lack of effective sealing (essentially loss of compression) in one or more cylinders. This will result in a rough idle. A gentle rock at idle is acceptable, however excessive movement at idle is the first symptom of cylinder bore wear. If you leave the car at idle with all ancillaries switched off, and you open the door wide and watch the top edge of the door, if it is moving significantly and unevenly you may well have cylinder bore wear.

If you take the vehicle to BMW they can plug it into the computer and check the idle quality. In most cases a simple (30 minutes long) test is sufficient to indicate whether the car is suffering – in very advanced cases it will take far less time than this. To be absolutely sure, though, BMW need to run a “leak down” test, which tests whether the leak down past the piston is within acceptable limits. This is the real proof. Even if the car is within warranty you will probably be asked to pay for the tests – but only if it passes! If the car is out of warranty, you will have to pay for the tests and this will not be refunded. The tests cost around £100.

In severe cases, the loss of compression is so bad that the engine loses power. Furthermore oil consumption increases dramatically as oil is sucked up the side of the leaky pistons. In really severe cases, the compression decrease is so severe the car will not start in cold weather.

Experience indicates that inflicted 6-cylinder cars display more severe symptoms than inflicted V8s. I have never known a V8 not start, nor use large quantities of oil due to the Nikasil problem, but I have seen or heard of both in the 6-cylinder engine.

What did BMW do about the problem?

When the problem first came to light, BMW were rather confused (as were the owners of the vehicles involved). However it didn’t take long for BMW to work out what was happening. Some of the cars were very new. BMW replaced the cylinder blocks and also tried to alleviate the problem by re-programming the DME to ensure higher combustion temperatures (a move which may have helped slightly but certainly didn’t solve the problem). As initially they had no contingency block material, dead Nikasil block were replaced with new Nikasil blocks. Eventually they switched to different materials, a different alloy called Alusil on the V8s, and iron liners on the M52.

BMW extended the warranty to 4 years and 100,000 miles in the UK (whichever comes first). Unfortunately for most owners, few cars do as many as 25,000 miles per year, and all Nikasil block cars will now be much older than 4 years. So they are no longer covered.

How many blocks have been replaced?

BMW does not give this information away. All I have been told is that it is a significant number, and that it is more in the north of England. A recent survey of vehicles in Auto Trader revealed that of recent 6-cylinder BMWs nationwide in the £7,000 – £15,000 price bracket (and with less than 100,000 miles on the clock) some 1% – 2% of vehicles for sale were advertised as having had a replacement engine. Interestingly, there appear to be very few 2.5 litre cars with an advertised replacement engine – but clearly the research is not scientific enough to say that the 2.5 litre cars suffer any less than the others. [Thanks to Dr Loke for his efforts doing this survey.]

The 1% – 2% figure is interesting, but it surely only represents the tip of the iceberg, i.e. those cars which have been fixed and where the owner recognizes this as a distinct advantage in the sales process. It is my personal opinion that the problem is so severe that in time the vast majority of susceptible cars will be affected – that is certainly what other unscientific surveys on the V8s ownership point towards.

I have also been given information recently from a very unofficial and extremely limited survey of 840i owners. 75% of the cars had had their blocks replaced, but only 25% of the current owners had heard about the Nikasil issue. The interesting point here is that it would appear that owners of very expensive luxury cars appear to know very little about them!

Will I be okay if my car has a full BMW service history?

Unfortunately no, for a variety of reasons.

Firstly, having a car with a full BMW main dealer service history does certainly not mean that the vehicle would have had an idle quality or leak down test routinely in the past. BMW do not broadcast the problem and dealers do not routinely check for the problem. Arguably they should, but there is no evidence to suggest that they do and plenty to suggest they do not.

Secondly, and equally worryingly, BMW appear to be reluctant even to test engines, but will do it if you insist and pay them to do it. BMW dealers must have hundreds of problem cars going through their workshops every year which the mechanics know about but which they ignore completely. They appear to wait until the problem gets so severe the owner stumbles across the problem himself.

Thirdly, BMWs warranty is only valid if the vehicle has a full BMW service history. They don’t extend it further if you have a service history; rather they curtail it if you haven’t!

Here are two examples I have personally seen of Nikasil cars which dealers appear to have ignored:

Case A: 1993 540i with 95,000 miles. Full BMW service history. Car also recently spent a considerable amount of time at a BMW garage having a new gearbox fitted. The servicing dealers appeared to have been only too happy to turn a blind eye to a problem that they really should have recognized, and probably did. In BMW’s own opinion the problem with that vehicle was severe enough that it would have been in evidence for 40 thousand miles or so.

Case B: 1995 320i with 78,000 miles. Full BMW service history. Car also recently needed new oxygen sensors for the MoT. The idle was so poor a knowledgeable buyer would probably have shunned the car even if he knew nothing about the Nikasil issue. The owner said that the car used around 2 litres of oil between services. At that rate of oil use, other components were probably being damaged: catalyzer and (perhaps) oxygen sensor.

Should I buy a car with a Nikasil block?

Cars with Nikasil blocks are good value; the trade is fairly aware of the issue (much more so with the M52 than with the M60 in the UK) and prices have been depressed because of this. This naturally filters through to private sales, even if the buyer and/or seller is not aware of the Nikasil issue. Cars which have had their blocks replaced are far more expensive. If you are aware of the risks and know that you may have to replace the block, there is no reason not to buy a Nikasil block car. It may be a useful bargaining tool. Forewarned is forearmed.

What do I do if I already have a car with a Nikasil block?

For peace of mind it may be worth taking the car down to BMW for them to test. It will cost between £30 and £70, depending on whether it has the problem and how easy it is to detect.

If you discover you have a car with the Nikasil problem, the first thing to do is to remind yourself that the car was good value because of the issue, and that although irritating, it is not the end of the world.

You then have three options: leave it until it dies, sell the car, or repair the car.

How should I try and sell my “Nikasil period” BMW?

The answer to this depends on whether your BMW still has the Nikasil block, or whether it has been replaced with the Alusil or iron block. If you don’t know, you need to find out BEFORE someone asks you so you can answer them.

If you have a replacement engine, you are in a strong position, and it is my feeling that you should certainly mention it in any advert you produce. A comment along the lines of “120,000 miles, 30,000 of which on new non-Nikasil engine”. A car with a replaced engine is peace of mind for anyone buying the vehicle, and is consequently worth somewhere between £1,500 and around £3,000 more than a similar car with an original block.

If you have the original block, do not despair. People do still buy these cars without even asking the question, and the best way to sell is to price the vehicle competitively. If you are asked, you must not lie, but if you are sure the car is not suffering, you might offer them a leak down test at their preferred garage, which you should offer to pay for if the vehicle fails. But the reality is that if you are asked, then the buyer is clearly aware of the issue and your chances of achieving a sale at the price you might like are considerably reduced. If you’re happy with a lower price, you may well be able to find someone who will take a risk, or who has contacts in the trade who can replace the engine if necessary. The alternative is just to be patient and wait until someone turns up who doesn’t know or doesn’t care…

How much does it cost to replace the block?

An 8-cylinder will cost around £3,500 (inc. VAT) at an independent BMW specialist and around £1,000 more at the BMW dealership. A 6-cylinder will cost around £1,000 (inc. VAT) less than the V8. These are the “book” prices; I understand that it may be possible to negotiate very substantial discounts off these prices at certain BMW dealers – a figure as low as £2,500 for the V8 has been quoted to me. The new M60 V8 is an Alusil bock and comes complete and built-up with a new pistons and a new crankshaft. The replacement M52 is an alloy bock with steel liners and likewise comes with new pistons and a new crankshaft. It is allegedly possible to re-sleeve the V8 with iron liners, but although I have heard of people doing this I do not know whether it is successful in the long term. It should be possible to get a machine shop to put sleeves in the 6-cylinder engine as well as is appears that it what BMW are doing on the replacements. The only alternative viable option would be to pick up an engine from a scrap yard. Make sure you get one that has already been replaced and is Alusil (M60) or has iron liners (M52). Please note (if you are going to get work done by an organization other than BMW) that you must change the pistons and rings at the same time as the block because they are also made of different (matching) materials.

Will BMW pay for the replacement?

Unless it is under warranty, in all probability no. The 4 year / 100,000 mile warranty may seem inadequate, particularly for a 4-litre V8 coupled to an automatic gearbox, but at the same time BMW cannot cover everything. They must draw a line somewhere.

If you have been the sole owner, or you can prove that someone (i.e. a BMW dealer) should have picked up the issue within 4 years, you may have a case.

If the vehicle has not got a full BMW service history, it’s almost certainly not even worth asking.

However, if you want give it a go (out of warranty), then I would suggest the following:

1. Do not be demanding or difficult. You have no rights, so the only way to tackle this is with gentle persuasion, not threats.

2. Write to the customer services manager for your country and copy your letter to his superior in Munich.

3. State your case, how long you’ve been a BMW owner, etc., and mention your disappointment.

4. Provide information (and proof) of the vehicle’s BMW service history.

5. Suggest you have contacts within the BMW owners community, but don’t threaten to bad-mouth BMW if you don’t get your own way.

6. Remember to play along with their assertion that the problem is caused by the fuel and not by their engine design (IMHO this is basically true anyway). Don’t wind them up by telling them it’s their problem. It isn’t anymore – it’s yours.

Wait for a response, and when it’s negative don’t give up. Write again. If you persist (and stay polite) you may get at least a concession.

The responses from BMW may take a while, so use the time to think about what you are going to do if you don’t win!

In January 2002 I was given information that indicated that BMW may have had an internal “deadline” for replacing blocks free of charge of December 2001. However I have recently heard (May 2002) of three owners who has just had a replacement block paid for by BMW – on a 1996 320i with 64,000 miles and a full BMW service history, on a 1997 520i bought in 2000 but bought from BMW with a 3 year warranty, and on an 1996 328i with 52,000 miles and a full BMW service history. So although I think that getting a replacement block free of charge may have got more difficult, clearly there is no “deadline” as such.

** I have had a communication for someone who recently had their block replaced:

Received 14.09.02


I can honestly say that I had to do very little to get my new short engine supplied and fitted by BMW. I purchased the car from John Warren Cars, an independent BMW dealer, who I contacted 3 months after purchase, having been made aware of the potential problem. He was aware of the problem of Nikasil wear but the car had passed an emissions test for it’s MOT and he was unaware that this car had a worn engine. I asked if he had any idea’s on what my best course of action may be, and whether the warranty purchased with the car covered the problem. From then on he arranged the leak down test at his local franchised BMW garage, Specialist Cars in Stevenage, and also lent me a courtesy car whilst it was in for 2-3 days. Needless to say the engine failed the leak down test and the report was sent to the warranty dept at BMW UK. I know that John Warren knew a couple of the people at the dealership, he must do as he has been dealing in BMWs for years, but whether they said all the right things to BMW or just sent the paperwork thru I don’t know. Any way after a tense 7 day wait they confirmed to me that a new short motor would be supplied and fitted by them and all parts and labor would be paid as a goodwill gesture. The only bad news was that I would have to pay for the oil and anti-freeze to go in the new motor!! They even said they would over look the cost of the leak down test, probably because it failed but what the heck.
I was amazed, having spoken to numerous friends in and around the motor trade and found several web-sites saying how unlikely I would be to get the engine paid for, I felt somewhat blessed. Even a good friend who is head of PR at Vauxhall said that he thought I may get the parts at a reduced price at best, as that would be their approach to the problem. Again when the car was in at Specialist cars John lent me a courtesy car, which helped out no end as I live in Essex, and use the car daily, the new engine was available to fit within 3 weeks of failing the test and was in for 7 days. Whilst in they replaced a steering joint which was a recall fault, several belts, hoses and an engine mount which had serious signs of wear, all for the cost of the parts only as while the engine was out the labor was covered by BMW. I collected the car on Sept 9th and have a warranty covering the new short motor, and a bill for £150.00 for parts and lubricants, I didn’t write a single letter or make a single phone call to anyone other than John Warren or Specialist Cars to arrange appointments and check progress. I can only say that if John did pull any strings or call in favors at Specialist cars he didn’t mention it, and I doubt that would have any impact on BMWs decision anyway. I would definitely recommend John Warren Cars,, to anyone looking to buy a used BMW he has a good stock of cars and can locate most others, I sound like his PR man, and also Specialist cars who were as efficient as you would expect and kept me informed all thru on what was happening, even when they broke the front pulley getting it off the old engine. Which added to the 3 days they quoted for replacing the engine, whilst a new one was ordered. As a final note I now have a 328 sport which goes like a scalded cat even being careful with the revs for the first 1000 miles, and a car worth every penny I paid and perhaps now a bit more. I don’t think this experience will help reveal the secret to getting a new engine, if there is one, but as I had a 6 yr old car, with 2 previous owners, 52,000 miles and a service history, though complete, with 2 independent garages stamps in it, and purchased from an independent dealer, I still got it replaced. Well done BMW, but then perhaps that’s what makes people buy BMWs again!!!”

Stephen White

There is a complete dearth of information on in Nikasil issue from a British or even a European perspective. The Nikasil M52s were never shipped to the States, so information about them is almost non-existent. There is some American information about the V8s, most of which would lead you to believe that this is a US phenomenon only. Beware, it is not!


I am not affiliated to BMW in any way. The information here is provided to help people and, naturally, comes without any warranty. Any decision you make is your own and nobody else’s. If I’ve got something wrong and you buy a lemon, sorry, but that’s not my responsibility. I’ve put my best effort in to make this page accurate and complete, but we’re all human and there may be mistakes. If you find something wrong, please let me know and I’ll correct it.Please also note that the opinions expressed are mine and mine alone. They are not the opinion of Lestac Ltd or Lestac Translations Ltd.

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