How many of you guys have replaced the dreaded tensioners on your 4.0S
Good poll to take.
Thanks John

 

done the tensioners,chains and slippers on my 98 xjr a few months ago. not the nightmare job i was expecting. the hardest part of the job for me was removing the crankshaft pulley, boy did that put up a fight! rest of the job went really smoothly.

 

Did tensioners on my xj8 a few months back. 193k on original ones.

 

andrew what size bolt did you use on the crank pulley? i know they are M8x60mm but what is the thread pitch?

 

wow thats a long time...I wish we could poll this and the block situation.....

How many still have the nickasill block?

 

Mine still had original engine. Wasn't replaced and neither has the throttle body that had issues in 98. Original tranny. I had original ballpoints and shocks until I replaced them a month ago.

 

i am not at home untill the 2nd of jan but if i remember correct the pitch is 1.5 ,will confirm when im back indoors.

 

still have nikasil block and throttle body. at 104,000 the old xjr still purrs like a kitten and pulls like a bull dog.

 

Cheers Andrew, no rush, wont be doing work on the car till next weekend as im out of town myself

 

I was wondering if the moderators could do a more formal poll?

Its interesting that some of you still have the nickasil blocks and some even have the tensioners......some high mileage as well.

So it seems not all those blocks went bad.

Nickasil has been around for awhile. I raced for 30 years and when I was getting ready to retire engine builders were starting to do this with race engines but it was expensive..........

 

I have a Nikasil engine. No oil consumption, no problems at about 120K miles. I changed my tensioners (secondary only) at about 90K miles. I also changed the thermostat housing to an aluminum one. Original tranny, has been serviced with filter and fluid change.

 

One poster somewhere said that all engines manufactured after August of 2000 were not Nikasil blocks. Could somebody clarify this if they know more about this.
This would mean that most if not all 2001 engines were iron lined and not Nikasil.

Having said that would mean 4.0 engines found in 2001-2003 are not Nikasil blocks as many on this forum claim....

This is good information to know with those wanting to purchase those year cars?

This is probably motivated of course by the savings in money without having to move up to a 2004 4.2 engine.......

 

You have a nikasil block........? I doubt you even have one if what was mentioned in the past is true.....a 2001 model 4.0 should be a conventional iron liner?

 

I have a nikasil block. The engine number tells the tale. That is the only way to tell. 0008181043 is the number. 2000, August, Eighteenth, at 10:43. Mine is before.

 

What year is your car titled?.....this will tell the tale too..!
Meaning engines built before this date were being installed in year 2000 cars and 2001?

 

Engine number is the determining factor. The exact number has been exhaustively discussed in past threads. It may even be in on of the stickies.

 

No, after that date all XK/XJ's got steel linered engines. The engine number does confirm what it is, the best way is to eyeball the unit's number stamped on the block. A lot of Nik units were replaced under Jag warranty with steel blocks. For UK, 2000 MY engines are steel, USA MY 2001. The USA cars are 1 year added, so a 2000 UK Euro spec is equal to a 2001 US spec.

If I was offered the choice of a brand new Nik block or steel one, I'd go for the Nik.
Tighter tolerances, harder bore lining, now no sh*t sulphur fuel additives and cheapo supermarket fuel from Venezuela, Formula One developed coating, no measurable wear after 2-300,000 miles, a lighter bare weight bock - it all adds up to a great development in engine technology, pity the sulphur fuel was it's cryptonite, damn shame that cost not just Jaguar pots of cash, but BMW etc that used the process while the bum fuel was around....

I've seen failed Nik linings, not pretty, chunks missing to tiny bits, all scrap. A compression test/leak down test - look for oil in the obvious places are the tests to carry out with a suspect unit.

Any AJ-V8 manufactured before August 13th midnight 2001 (from memory!) will need the timing update...

 

193K miles on my original Nikasil block. I have original tranny and all. Car has no oil leaks or fluid leaks of any kind and still has power to throw you back in the seat. I onlyy have changed my secondary tensioners and probably will change out the VVT unit soon as it ticks until I hit 1500 RPMs then you hear the whirrr and it kicks in and engine is quiet. Trying thicker weight oil next oil change to see if that makes a difference.

 

Jaguar's own technical description for the VVT units state that operation is affected by oil viscosity & temperature. Later V8's were fitted with a higher-capacity oil pump & engine oil temp sensors.

The problem is lack of enough oil pressure for the VVT units at idle on a hot engine with low oil viscosity-hence the later higher-capacity oil pump. On earlier engines the VVT noise can be reduced by using thicker engine oils.

 

can you confirm the 1.5 pitch?