Any XJR or XJ8 built before August 2001 came with plastic chain tensioners. If they have not been changed, you need to do so. You will find many contrary opinions to much of what is discussed here, BUT NO ONE WITH A BRAIN WILL ARGUE THIS! There is an argument about whether you should do the primary and secondary tensioners, but the secondary tensioners need to be checked now. Some would tell you to not start the car until you do so.

Both the primary and secondary tensioners are subject to come apart and fail, but the secondaries are easier to change and are much more likely to cause a valve crash and essentially destroy the engine. Make your choice!

 

Off-topic ON: I did the secondary tensioners a couple of months before when I had to deal with sudden "restricted performance" and rough running due to a failed knock sensor and bad coil.
When eliminating potential causes for the issues the check for the timing was on my list too. And since I had to pull the valve cover anyway and discovered second generation plastic tensioners, I decided to replace them at the same time (using the zip-tie-method). At that time my MY2000 XJR got 110k miles on the clock and was running fine and silky smooth. After removing the tensioners I detected first signs of failing (see attached picture) which could'nt be seen with the tensioners in place.
I'd not recommend to be overanxious with this issue. The supercharged vehicles got no VVT and therefore the tensioners are less stressed than for engines with VVT.
So if you come along with checking the timing and the status of the tensioners, it's not much more of time needed to replace the tensioners as well (if needed).
Top tipp: If the valve covers are pulled, you can easily identify the status of the primary tensioners too! With a strong flashlight you can light alongside the engine's front cover and see the primaries (see picture). In my case the primaries had already been replaced with 3rd gen, but the secondaries hadn't...don't know about the sense, but who knows....

Off-topic OFF

No, it wouldn't. They share the same tensioners.
You never know, if the pre-owner didn't mentioned that. I think you have to pull the covers and take a look(no worries, most times, you can re-use the gaskets after cleaning, did that as well).
Noise is not a sufficient indication - see above.
Yes! It's no big deal in doing so...and since the charge air coolers and the supercharger outlet duct are on almost the same level as the header tank, there might be air trapped in there...

Cheers, Alexander

PS: Don't be irritated 'bout the numbering of the pictures, they're out of a How-To I made for the german Jaguar forum.

 

Well, we got a hold of the son of the original owner. The tensioners haven't been changed. So, I'm ordering them tonight. I've looked over the blackonyx pdf on it, and the sight of those chains makes me think it may be more that we can do ourselves. We're going to look at the zip tie method and the way it was done by someone else without removing the cover. How easy is it to mess up the timing or something else?

On a good note, the water pump has been changed. One less thing to worry about. He also said that after the alternator was changed they had a small dripping leak. He didn't know if it was ever addressed. So, maybe another lead on the coolant loss.

So, tomorrow we clean the coil and check the spark plug, replace the tank cap, search anywhere near the alternator for a leak and then we'll redo the bleeding process. Busy day!

I have a question about the bleeding instructions:

. Remove the threaded plug and Dowty washer from the charge air cooler fill point.

• NOTE: To ensure that air is not drawn into the system during the following operations:
Do not remove the cap from the header tank whilst the charge air cooling system is open to atmosphere.

2. Fill the cooling system at the header tank until the level stabilises near the top of the charge air cooler fill point. This will take some time, as air is being purged from the system.
Ensure that the header tank is full.

It seems a little confusing. Do you have to put the cap on the tank and then check the charge air cooler? Or do I fill it from the header tank (expansion tank) while the plug is open and watching to see when it's full? Only one open at a time open or both?


Appreciate the pics and all the advice.

 

First, make sure that the bleeder hoses are properly connected at
the header tank. It has been mentioned a couple of times with
no response that this has been checked. If they are not connected
to the proper positions, there will be coolant loss.

I posted a coolant fill technique involving a funnel some months
ago that is far less fiddly. It takes advantage of the coolant shrinking
when it cools to fill to the max. I do not lose coolant.

You might find the thread using coolant and funnel as the search words.

I think it is in general tech.

 

Thanks, I'll definitely look for the thread. The bleeder hoses are on correctly. That was one of the first things we checked.

 

Plums, (or anyone),

We tried the one shot method you posted. The problem is it simply ran out the overflow in the wheel well once the supercharge port was full. We kept it at 2 inches but even before starting the engine it simply flowed in there. Does that mean it's full or is there some other problem?
Thanks

 

Wrong funnel.

Mine forms a snug fit at the neck because it is the
same diameter as the neck itself.

It was only a couple of bucks at Walmart I believe.

 

double post

 

ljmctyer:
So, do I understand you correctly?
With the expansion tank cap ON, you filled through the supercharger port, and water ran out to the overflow tank?

If that is true, one of two possibilities exist; 1) Your expansion tank cap is completely shot OR 2) You have the overflow pipes we have been inquiring about on backwards! Well, I guess there is the possibility that some other weird piping screwup has happened!

Why? because the cap seals against the neck of the expansion tank with a pressure relief spring, sealing it until a pressure about 1 bar (I think) is developed. The overflow tank pipe is above that seal and if water is flowing out there, the cap is bad. On the other hand, the bypass pipe is below the seal in the neck. If the pipes are reversed, the water will flow out the lower port to the overflow.

 

Hi, No we filled thru the funnel at expansion tank, it was a good fit, until it was full at the supercharger. Then we put hex back on and started car with 2in coolant in funnel but it ran straight to overflow. We cut it off. Started over, it worked this time with lots of air coming thru. Ran at temp for an hour, still air coming out. Any Idea? Hose from little pump to supercharger seems to have very little flow. Also, everytime fan comes on it puts air bubbles out.
Thanks for any help.

 

This has been mentioned a couple of times: you said they are correct.

As does Ross, I have my doubts. Please double check, the inboard tube goes to the tank in the left wheel well ; the outboard (closest to the left fender) goes to the nipple on the upper left of the radiator.

 

Also passenger floor boards are wet. Not orange, though.

 

Yes, the inside one goes to the overflow and the outside one goes to the radiator? I've looked at pics many times. Is this correct?

 

That is correct.

Now with the cap off the overflow have someone race the engine; if you are seeing large bubbles in the overflow, it's a head gasket.

 

A question, if the heater core is leaking could it be sucking the air from there? (Please!) He's gone to work now, so we'll have to race the engine tomorrow to check for large bubbles. We did get large air bubbles while bleeding it, without gunning it.
Thanks

 

Hi, thought I'd give an update. Sorry it's been so long, the whole family was down with the flu. Then we spent a weekend replacing the rear upper shock bushings, fun! But a sense of accomplishment, anyway. And no more banging.

We had a coolant combustion test run on the Jag. It was done at start, at temp, and after running at temp for a while, also ran again after coolant flush. All came back negative. Also, oil still looks good. So, hopefully that rules out head gasket failure.

We replaced the intercooler water pump with a bosch pump. The old one didn't seem to be working. The hose on the right side of supercharger didn't ever seem to have much flow. Now the supercharger seems to stay cooler. There still doesn't seem to be much flow, you can feel some fluid, but not full, until the car reaches operating temp, then it's full. Is that normal?

I've ordered the heater hoses that run under the supercharger. Question: Do I need to replace any gaskets, like for the throttle body? Or anything else while we have the supercharger off?

We're going to attempt to change the secondary tensioners at the same time. It seems like it may be simpler while we have the supercharger off. Is this a good idea?

If anyone has any links with pictures or videos on the supercharger removal that would be great.

Again, thanks to everyone for your help. We would never have attempted this without your help.

 

Hi ljmctyer,

just give me a while and I'll translate my german howto as good as I can. Includes all parts incl. part-no that I replaced coming along when I replaced the knock sensors. For replacing them I had to remove the supercharger as well and decided to replace all gaskets, seals and hoses which got in my way ;-)
Yes, definitely! Since everything is off, you don't have to bother with e.g. the injector rails, the intercoolers or coolant hoses etc etc that might get in your way.

Cheers, Alexander

 

Remove the hood. MUCH easier to access everything while you're working. Also replace the plastic coolant 3 way T on the left side of the throttle body. Good luck.

 

HERE WE GO!
Well...it took me almost a day to get everything off and another to put it back. Finally, as I refilled the coolant system, I noticed a small leak coming from under the supercharger. Obviously, I didn't clamped a hose firm enough.
So I had to disassemble it all over again - this took me 3 hours and another 2-3 for having it back together. So you see....practice makes perfect!!!

As I mentioned in the attached HOWTO, I removed the charge air coolers and the injection rails as well, since I wanted to replace the intake manifold gaskets too. It's just little more work, no big invest and a perfect opportunity, when the supercharger is off - I wanted to minimise all possible risks.

And in addition to this, I replaced the supercharger oil and coupler too. Since the pulley drive shaft had play in the coupler mechanism it was a good idea (when you turn the pulley and the roots screws of the supercharger do not start turning instantly but react delayed, then the coupler is worn. If you turn the pulley and your coupler is worn, you'll understand what I mean).

Good luck and keep us updated!
Cheers, Alexander

 

When re-assembling you can look up all the torques from JTIS. Here's the link for downloading the pdf (LINK).

Cheers, Alexander