Hey everyone, the name is Ken [2000 XK8/X100/AJ27], and over the last year I’ve basically become a master Jag mechanic… THE HARD WAY. However, I’m now at the end of my rope.
here is what I’ve replaced/fixed in the last 30 days
Both Heads were worked over and machined, and New Head Gaskets
Timing Chains and Tensioners (primary and secondary)
All 8 Coils, and All 8 Plugs
Radiator and Hoses
Primary Overflow Reservoir
Thermostat Housing Tower (aluminum upgrade) and Thermostat
Water Pump
3 Oil Flushes and new Filters in the last 7 days
2 Complete Coolant Flushes in the last 7 days
8 Valves on the Bank 1 intake were bent and replaced (stems were all grinded and polished to match the resurfacing of the heads
Oil Pain and Oil Sump Strainer, completely cleaned out
Set Timing and Checked Timing no less than 4 different Times (AJ27 = VVT)
All 32 Valve Guides
Upstream Bank 2 O2 Sensor
AS A SIDE NOTE THE CHECK ENGINE LIGHT IS NOT ON
AS A SECOND SIDE NOTE, I’M GONNA WATERBOARD THE FIRST PERSON TO SAY ITS A WEAK BATTERY
The result of all the work I’ve done on this vehicle has yielded a car that performs poorly and runs 15 degrees HOTTER (10 minute idle at any ambient temp, Engine compartment feels like its literally on fire) than it ever has in the year that I’ve owned it. Sensor reads temp at 208-210 and my on-board OBD-II monitor confirms the temps. It’s like the car is consuming itself from the inside and I cant stop it.
Any advice minus the aforementioned weak battery nonsense would be GREATLY appreciated, for I am now at the point of my Jaguar ownership where I’m ready to harm the car (on purpose) just to feel better for the time/work and money I’ve dumped into this seemingly bottomless pit
Welcome to the forum, not sure why you would think overheating would be caused by a weak battery?
With the work that has been performed the first thing that comes to mind is whether the engine was in the correct position as far as timing is concerned. I believe these engines are NOT timed at TDC but at some other position?
Hi there. In 2000 I understand they changed from a Nikasil (Nickel plated) cylinder bores which gave problems to a steel bore. Also the early water pumps were plastic ? I am thinking of buying a 2000 XK8 and this forum is probably going to make me change my mind with all the problems these cars seem to inherit ? Besides over heating did the car run OK ? Cheers Nick
Hi Nick, welcome to the forum. This wasn’t my car and the original poster has not had the common courtesy to respond. I have a feeling that my suggestion hit the nail on the head but until the OP comes back we will never know. If the car you are looking at has survived this long then the engine should not be a worry. I am running a ‘99 XJR 4.0 and the engine is fine at 99,000 miles whether it has the Nicasil bores or not I can’t confirm. BTW the bores are not nickel plated, the cylinders are bored directly into the aluminium and then the surface of the aluminium is etched away leaving the silica proud, this was attacked by the high sulphur content in some petrols. Jags were not alone in with this problem BMW also suffered.
Hi there and thanks for the reply. I am just considering purchasing an XK8 as I think they are a pretty cool looking car and hope eventually might appreciate. Also looking at Holden Monaro V8 coupe. The Jags seem to have a bad rep as trouble some and expensive to maintain. Not too sure which direction to steer. Cheers Nick
Do you by chance know what year the tensioners were upgraded from the plastic ones ……… from what I have found looks like late 2000 on some of the 4 litre models
I think thats about correct but there may be a V3 out as well. I take it you are either in NZ or Aus?
If you got to your avatar top right you can place your country flag under preferences from memory.
To my knowledge the AJ-V8 engines switched over to iron bores sometime in 2000, so you need to get the VIN number of the car or better yet the engine ID number to know for sure.
However, if the engine runs well and has good compression (which I recommend testing) it probably doesn’t matter if the engine has a Nikasil bore or not at this time. The high-sulphur fuel that eroded the Nikasil bores was phased out by most countries in the mid to late 2000s, so unless you’re operating the car in a country with no pollution standards, there is little risk of damage now.
The tensioners were updated I think around 1999, but this design still warranted further improvement so I think the final all-metal tensioner design was implemented in the middle of 2001. All 4.2 V8s have them.
The VIN will not be accurate. Just find the ENGINE NUMBER to be sure.
(August 13, 2001; engine S/N 0108130000 onward were supposed to have the metal body tensioners.)
You could do it the old fashioned way and remove the cam covers and LOOK?
Most of my Jaguar V8 sedans have Nikasil bores and I have no problems with them.
They should outlast iron bores if I don’t use high sulfur fuel or OVERHEAT the engine.
The reason I would ignor vehicle manufacture date is because the engine was made BEFORE the car was made and ‘what if someone replaced the engine?’
What if someone already replaced the chains/tensioners?
