I have seen it said often that if a Nikasil engine has made it until now, after the problem with bad fuels with high sulfur went away, then it should be good to go.
Not so. My Nikasil engine with just under 80k miles has failed. Took me a while to figure out this was the issue since I wasn't expecting it.

At first I thought the timing chain tensioners had failed and the chain skipped a tooth. Replaced them but that did not fix the very rough idle. Then I thought maybe it was electrical related like coils or fuel injection. Then I got a compression tester and found low compression on two of the cylinders. 70 and 107 compared to 120's -130's psi for the others (supercharged 99 XJR). During my research on this forum I read that valve seats can drop if overheated due to air pockets in the coolant. Thought I finally found the possible issue. So I bought a borescope to see if I could see the problem. Everything seemed fine at first but several looks later I noticed roughness at the very top of the cylinder bore. The rest of the bore was smooth. So I finally discovered the Nikasil failure.

What's weird is that it happened so suddenly. Car started and drove normally for about 15 miles and I was cruising gently. When I came to a stop, the engine began to idle very roughly and the car shake, like it was about to stall. Sounded like an American muscle car with a hot cam. It did stall several times when at stops on the way home. Once driving with rpm's higher than 1500 or so it's fine and you don't notice anything wrong.

So that's my Nikasil failure story. Attached pictures from the view with the borescope.

 

That sucks, sorry to hear.

 

Yes sir...nikasil was a great idea...until it wasn't.

 

Oh wow! So sorry to see this. Recently sold my 98, would definitetly think twice in the future about buying another early car after seeing this. Planning on fixing it?

 

Were you having other issues prior? I.e. oil burning, poor performance etc.

Im lucky in that when i head my heads off, my nikasil bores were in good shape. My car also burns zero oil so i wonder if you had early warning signs.

Sorry to hear you sold your 98 87lc2

 

Some good questions, almost sound like there was no warning at all which is quite scary. Nice that you were able to check yours with the heads off.

Since I got the X350 I hadn't used the 98 much at all and stupidly let it go. Put it up for the "make me sell it price" and it sold rather quickly which was a surprise. Regret it already and have been quietly searching for another supercharged Jag, either an X308 or X350 R.

 

I'll be fixing the car but probably not this engine itself. I'll replace it with a used engine.

I didn't notice anything out of the ordinary. Started and drove normal until it didn't. I would have expected this kind of failure to happen more gradually and not so suddenly so it didn't even cross my mind it could be this. No oil burning just smoke on startup if it sat for weeks but that was due to oil leaking past the valve stem seals.

 

Whelp, now that the bores are gone, I suppose it could be time to see if any of those snake oil compression fixes actually work?

 

90s bmw and jaguar used the poverty edition of nikasil, even then failure is super rare unless you get hit with really bad gas.

other makes and models with nikasil never ever ever ever ever have these issues

 

I believe motorcarman said that overheating can also damage nikasil.

 

There are some engine oil additives that also contain Sulphur.
Today's gasoline still has some Sulphur content, although for
most, it is negligible.

 

Lucas oil stabilizer probably may help
friend of mine has used patix to make his engine stop smoking heating the adhesive well saved him about 3k
Sometimes these things works

 

There is no "poverty edition"of nikasil. The failures in Jaguar and BMW engines were related to sulphur in the fuel and lower operating temperatures in the engines (good in most instances, but not good in the mix of sulphur and nikasil). When Porsche used nikasil in the 911, for example, they had no reported problems because the engines ran significantly hotter and the cars were much less likely to be used for 2 mile runs at low speed, or started and moved out of the garage and shut off. The issues in Jaguar engines came principally in engines not run long enough to be thoroughly heated, and using fuel with high sulphur content. As you point out, many of the nikasil engines are still in use without apparent issues.

 

you can drive a water cooled 911 turbo on arab gulf fuel all day long, not a hot running engine in any way shape or form. again this condition only exists in the bmw engines and the jaguar v8, it never ever happens on anything else no matter how you drive it. properly done nikasil cylinders are proven 100% compatible with any gas on the market, jaguar's wasn't.

 

I'm a bit shocked at this - looking at the pictures - it seems like a (long term) gradual wear to the bore coatings, with lots of pitting at the top of the cylinder.
The long cranks of death I thought are long past but that's brought it back into focus. A steel liner short block, and some refresh work on the heads will give you 100K trouble free miles,
it's down to the choice of new car or new block.

 

Yeah you would think it would be gradual. Unless there's another culprit for the sudden rough idle? But the low compression in the two cylinders (one has more damage and therefore lower compression) should explain it.