Just got Blackstone lab report. " looks like a nice engine ". My question is, does anyone know what to look for in these numbers, regarding the condition of a Nikasil engine in peticular? The report said it had a little too much silicone, but the tensioners where just done. Also, can it be determined if the old oil was synthetic? This was my first oil change, so I didn't know what was used before. The engine has 20,000 miles Thanks,......mick

 

mick,

What numbers?

Odd that the tensioners have been done at 20,000 miles.

Odd also 'a little too much silicone'. Since the nickel is the component which erodes from the bores with the acid created when the engine is cold, this may be an indication of the loss of nickel from the bore: my chemistry is too rough now to write out the reaction formula to work it out - you've got Al + NiSi + fuel formulation + H2SO4 created when the engine is cold: do we have an Industrial Chemist in the Forum?

Avoid high sulphur fuels (easier now than when the engine was built) and avoid short runs in the car that don't get it up to operating temperature so that you don't leave Sulphuric Acid in the cylinders after switching the ignition off (that 'water' that drips out of the cold exhaust is as acidic as hell, and was created in the cylinder).

Cheers,

Languid

 

I have information on my page but not sure it will provide you with what you are looking for JagRepair.com - Jaguar xk8 / xkr 1997 - 2006 Nikasil is under the engine section.

 

If you can post the resulst I can give some comments.

 

some results;alum...4 chrom...0 iron...9 copper...5 lead...1 tin...1 molybd...89 nickle...2 titan...3 potass...0 silv...0 boron...113 silicone...36 sodium...24 cal...2490 magn....12 phosp...791 zinc...994 barium...1 no water or antifreeze insolubles....0.3

 

How many miles where done on the oil you have tested?

 

avos, mileage on oil was 4,100. During that time, tensioners, water pump and thermostat were changed for preventive maintence. I thought maybe that was the reason for a high silicone reading. I've had no compression test done, and was just wondering if this analysis of the oil would show any clues as to how the Nikisel engine is holding up. I appreciate all your responses......mick

 

The values are all very healthy if I compare it with other engines from where I know they where ok. The silicon is indeed higher than normal (but not alarmingly yet imho) and that could be due to silicone used as Blackstone says, but also small air leaks (i.e. the oil dipstick not fully in the block).

I have also tried to find out if one could check based on the oil analysis the status of a nickasil engine, but have not found any clues for this. The best way of checking the status of a nickasil lining is to measure the blowby gases (and not a compression test), but as almost no one has such a device, the next best indicator for a nickasil engine going bad is higher oil consumption, and oil coming from the engine breather tube into the intake flowing back to the air filter.

 

As you said the blowby test is nonexistent and Jaguar decided to use a compression test. With the compression test you are checking more than just the cylinder walls you will be checking the piston compression rings, valves and head gasket. From what I have been told the piston/compression rings on a Nikasil engine are different than on a steel block. This car has 20,000mi, I would do a compression test and drive the car. Use a good fuel additive once or twice a year to maintain a good fuel presentation and have fun.

 

Gus,
In the UK, where the issue has been most serious, Jaguar had a blowby measuring device for dealers (Partno 303-708A), and that was used by them to determine the state of the nickasil liner (NOT a compression test). Based on the results (ie >40lpm) Jaguar would warrant a new engine.

 

Yes I know I did see it in operation. I went into one of my where can I find it modes and no one would provide it. I think I recall hearing of a person that might have one in a locker somewhere. In my hunt for it I did find out that Jaguar would use the compression test as a substitution. If I recall a video was made showing the entire operation of the test.