timing chain guides? It just started doing this.

 

Doesn't sound good, I think it's time to take a valve cover off and peak inside.

If you find you still have the original orange timing chain tensioners, replacement of the primary and secondary tensioners with MKIII metal type are due.

.

 

it does have the original guides. Only 85k miles. Would guides that have failed cause this noise? I’m now getting check engine reduced performance message.

crap. Car has been running brilliantly the past couple years.

 

Age has as much to do with deterioration as mileage, here are my tensioners at 69,000 miles and 17 years of age.

You have probably jumped one tooth on the cam gears, if it jumps one more it will basically destroy your engine. You would be well advised not to run the engine again and fit new tensioners/chains etc. immediately.

.


.

 

if you jump a tooth it will run like garbage

just open the valve covers and see what’s up. secondaries guaranteed to be cracked or your money back, primaries are a waste of time unless your guides have literally fallen to the bottom of the oil pan.

 

Primaries can go bad too and not to mention chains stretch over time. I've pulled primaries out that were cracked all the way down the middle and they have plastic oil tensioners too. If those tensioners no longer pressurize then you have both chains loose. Just replace them all and not worry about it for another 100K.

 

Not entirely true; we had a XJR here with a 1 tooth jump, it ran perfect at idle, just did not have a whole lot of power higher up.
The perfect idle was actually a big distraction in the initial trouble shooting, so agree, open up the covers will tell you more.

 

Is there a kit someone can buy that includes the components required to do this? Half a dozen Jag tools required as well. Might as well replace the thermostat while I’m at it.

 

https://www.ebay.com/itm/333725623764

https://www.ebay.com/itm/372666376404

https://www.ebay.com/itm/232803748113

even comes with metal impeller water pump that welsh sells for $39.99

 

Use the special tools to correctly position the crankshaft and cams. The correct cam timing is 45 degrees AFTER TDC.

Here is a link to the AJ-V8 Engine Course:

https://www.dropbox.com/s/vqpy3bbjzd...e_168.pdf?dl=0

Pay particular attention to page 74 of the PDF (page 26 of the course) on the correct timing procedure.

 

I just got done with this job on a customer's 1998 XJ8 this week. The secondaries had already been done but I tore it all down and replaced all the parts except the recently replaced secondaries. 10 hours labor and several hundred in parts. (timing components and gaskets/seals)

The guides/blades were cracked and flaking apart. Chains were stretched.

Been about a year since I did the last one and I forgot how much 'fun' it is!!!!!!!!!!! (I'm getting to old to loosen/tighten the crank damper bolt)

 

10 hours is pretty good, it took me 20 hours doing it for the first time, and I figured I could do it a second time in probably 15 hrs.

That crank bolt is a SOB!


.

 

Jaguar warranty time is less than 7 hours but the real world time is about 10.
I have done a few dozen on the AJ26, AJ27, and AJ28 engines so it is not like it is a new thing.
The bolts seem tighter than they did 20 or 30 years ago? (don't seem to tighten as easily either)

 

I got a 4 foot 3/4 breaker bar for the crank bolt and a pulley kit to hold the crankshaft harmonic damper in place. That made it slightly easier. Tightening was the real job and required two people, one to hold a wedge against the torque converter and the other to tighten.

 

I think you might be right. I have a 250 lb friend who helps with big jobs and whenever timing come up he says "Not the huge bolt again".