Hey, everyone

In attempt to find the correct spark plugs for my Jag, I followed the attached document I found in another thread, and the spark plugs needed are specific to the year, and since mine is a 1999, there is that grey area where they switched from the AJ26S to the AJ27S. I found the engine serial number, but it seems to read 000518 ****(couldn't read the last 4 numbers). Does this mean that the date is 05/18/2000? My VIN/registration claims it's a 1999, so they must have swapped in an engine from 2000. In this case, what are the correct spark plugs to use and the gap?

Thanks.

 

I'm pretty sure the serial no for you car should be on top of the block, just to the left of center near the front. I recall checking a 2000 XKR and I had to climb on top of the engine and use a flashlight to see it.

 

Yeah, I had to use a flashlight. It was located near the coolant inlet housing to the engine block, which is on top of the block to the left on the front of the engine. This was advice from another thread I found.

 

You can ring a Jaguar dealership for the info, and as long as they carried out the engine replacement they'll have a record. There's usually a green tag on the back of the engine, under the throttle body area I think?

I've used the NGK Iridium IFR5N10 on a number of different R units without issue.

 

Called the Jaguar dealer in town was of no use. They couldn't tell me anything, and told me that the database they have is exclusive to their dealership and not nation/worldwide. But I did find a green badge on the back of the engine located where you suggested. I also read the last four digits on the date, which in total is 000518 E 0025 (there was an 'E" engraved between the separation, not sure why)

I guess the engine was replaced. And the date of the engine is 5/18/2000 at 00:25 but this doesn't cover the nikasil date, which is august of 2000. So maybe it was replaced because of tensioners, which I have yet to check.

Do I still have the AJ26S engine then, so what is the clearance to set on the spark plugs to use?

 

Even if they replaced the tensioners they would be 2nd gen and need to be updated. I lot of those early engines were replaced because of high sulfur fuel erosion of the liners or overheating due of water pump failure.

 

It's strange because it was only replaced about a year after the making of the car, so what could have happened to cause a need for an engine replacement? I would assume the erosion because the pump could easily be replaced, but if it were the nikasil erosion, then it would need an engine replacement because it is internal.

As for the gaping, I could check the clearance on the ones on right now, but I would like to ensure the exact specs for the engine to run in ideal conditions.

 

The early AJ26 water pump vanes would fail, causing severe overheating which destroys nikasil liners. If the temp. gauge was actually functional many of those engines might have survived, but it reads mid scale until about 230F then suddenly jumps to red, which is often too late.

What plugs are you using? According to TSB 303-29 the gap should be 0.052". Thanks again motorcarman if they are OEM.

 

I think you're correct--seems reasonable, but would they really put another engine with the same nikasil lining, maybe with an updated water pump? I had the car over heat to about 80% of the full range on the temp gauge a few months back, but it has been running well since then, so I don't suspect it should be an issue. And I am unsure what plugs I have in right now, since I only got the car last October.

And thanks for the TSB reference number. I will get NGK PFR6G-13E (replacement for nca3850ha 2) plugs and set the gap to 1.3mm (0.00511in).

 

On cleaning my engine to replace the heads, I went looking for the Engine Serial Number to record in my documentation.
I believe this is an AJ27 engine as it has steel liners and most of the visual things I find indicate an AJ27.

2001 XJ8 Base X308 AJ27 106k miles VIN SAJDA14C41LF23776 which shows the following configuration from the VIN:

SAJ = Jaguar
D = USA (Market - Airbags)
A = Automatic (transmission / Steering)
14 = XJ8 (vehicle line/Body Type)
C = XJ8, XJ8 Sport, Vanden Plas, XK8 - (Emissions)
4 = ?? Manufacturer Assigned
1 = model year (2001)
L = XJ 4.0 liter N/A : Browns Lane ( Model Line / assembly Plant)
F = XJ Sedan, Super 8 ( Model)
nnnnn = Sequence number of manufacture


Referencing the Engine Training Manual, the Serial number "should" be stamped on the flat surface front and left of the coolant housing as below:


Surprise, Here is a photo at that location on my engine - note the serial number flat is blank:


Top Front of Engine no serial number?

I have searched the engine and can find no places other where there might have been a glued on metal tag ( like on the top rear of the engine indicating a replacement engine, so I am more than a bit curious about this engine - more important, how to fully assess what the exact model and manufacture ranges are so I make sure I have the correct parts.
It is definitely a metal liner engine although the manufacture date on the door VIN label is 09/2000, car manufactured new for the 2001 model year.
Before I purchased this car, I reviewed all the repair records at the used car dealer that they had obtained from the dealer and I do not recall seeing any significant or major repairs other than service which ends at about 30-40 k miles, after that- who knows.

What other indicators can I look at to fully identify this engine type and manufacturing data? Of course the dealer is completely worthless, they are not interested in an 18 year old Jaguar.
In the mean time I will clean off the other engine data flat on the left side of the engine block forward of the block drain plug to see what might be there.

There is additional data stamps that run under the Oil pump, but I cannot see all of that unless I remove the oil pump which I am not inclined to do at this stage of the rebuild since I can hand crank the crank and get oil to the top of the engine in 1-2 rotations. Photo of the front inside of the engine here :

Front Engine - inside the timing cover Stamping information

The "SA 20" stamped in the upper right square is most likely showing the market or manufacturer as "SA" are also the first two letters of my VIN - but that is pure speculation.

I can't seem to locate any information for the stamping on this area of the engine to decipher the codes or numbers, but since this is engine block locations only, I would guess from my experience working on the GM 6.2 all aluminum engine line Controls automation and tracking in Spring Hill TN that this is the information applied as the block progressed through the different manufacturing steps in machining showing things that associate to the specific block build configuration.
Anyone have this information on these codes for a Jaguar x308 - apparent AJ27 engine?

Gotta love the auto industry, from my experience working with Ford, GM, Mercedes manufacturing it is always a race to get the car off the end of the line as fast as possible, unless the vehicle is limited production extreme low volume vehicles.

Cheers!

 

On AJ27-s, they moved the engine number to somewhere on the left side of the block. It should be "on a vertical rib on the left side of the block, viewed from underneath, just above the steering rack" (or near the engine mount). It seems that it can be seen through the wheel well.

 

Yes, early engines had the engine number stamped on the engine block close to the thermostat housing, later AJ27 engine numbers can be found by removing the left-front wheel and shining a flashlight over the front chassis to a "bulge" on the engine block just behind the upper control arm..

 

Thanks