I have the dreaded V8 and I have to change the tensioners but im not sure if I should change all of the chains and tensioners or shud I just change the tensioners that are broken and the relative chain? Also im about 90% one of the tensioners are cracked or broken.

 

Opinions on that vary down here.

IF, and I think that is the key here, the engine has the "known" early tensioners, then simply changing the top units is all that is done.

IF, again, the tensioners have started to "break up" then the top chains are also replaced.

Of the numerous 4ltr engines in our group, only one has had the lower anything attended to.

Mileage travelled I reckon is the key here, as most of these were sorted very early in the engines life, so engines that are now up to 17 odd years old, would possibly require chains as well, simple as a "good idea at the time".

I am looking at one of these for a mate today, and "Full dealer service" is the blurb, but the owner, and dealer, have NO idea if the tensioners have been upgraded, kind of scary really, and at 74000kms more than likely they have NOT been sorted. I will pull a camcover and actually look at it, to be sure.

Many others will answer this as the day progresses.

 

Good to know, right now it's got 180k on the odometer

 

Since you are "up there" and that odometer is in Miles, I do not believe for one second that the version #1 top tensioners are still in there.

Version 2, mmmm, maybe.

Version 3, definately in MY opinion.

The #1 were failing at less that 50K kms, and #2, were really not much of an improvement. #3, are the "full metal jacket" units, and the same as the 4.2ltr, and are not known for any issues.

The one I looked at today has #3 units, so buttoned back up and the deal was finalised. He is now somewhere on some highway somewhere in Australia, SMILING like a bloody cat that just caught the pet canary.

Another thing we have discussed down here on occasions, usually at a BBQ and a few Reds under the belt, is the use of the "correct" viscosity oil in these engines. The use of "heavier" oil has all sorts of ramifications. The guys here all use 0W40, all year round.

Good luck.

 

What's the typical temperature range there for winter & for summer?

I'm surprised at the 40, especially.

 

0W40 is one of the four viscosities recommended by Jag. I'd probably use it too if it were commonly available here.

+1 on the comment about avoiding heavier weights or really any weight not endorsed by Jag.

Flame suit on.

 

Yes, 40's in there but with VVT and so on, I'm wondering why not use 30 (maybe even 5W30).

 

With that number of miles on the vehicle, it is probably a good idea to remove the RH cam cover and look at the upper tensioner to confirm the version. In my experience with the 4.0 Litre engine, it is best to replace all the chains and tensioners as I noticed several had cracked primary timing chain tensioner blades and guides.

The overall condition of the vehicle given its age must also be considered as the job can be expensive it you are unable to do it yourself. There are threads with instructions and photos on replacing all the timing chains and associated parts on this forum.

 

Thanks, I'm taking everything apart tomorrow so I'll know exactly how bad it is. Im pretty sure the timing jumped, is there a certain procedure to reset the timing or do I just need to turn over the bottom crank pulley by hand until it reachsz TDC and the two pairs of cams ' flats ' are parallel to each other?

 

There are several special tools required to perform the work without causing damage to the engine. You can download JTIS from this forum under the 'sticky' section at the top of the page, or purchase the Workshop Manual from an online vendor.

Under no circumstances is the engine to be rotated anti-clockwise when viewing the engine from the front of the vehicle as the connecting rod and main bearings can be damaged. The tool to lock the crankshaft cannot be used to hold the crankshaft in place to remove the front damper.

 

That is very interesting and I have not heard that before?

Can you explain what happens when you turn the engine the wrong way? Or is the danger the crank bolt will unscrew?

On my STR I think I have turned the engine backwards once or twice using a socket on the crank bolt or using the belts. Not for timing changes but to check something.
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It is possible that the bearing surfaces may be damaged by the crankshaft journals. There is such a warning in the Workshop Manual as well.

 

So I finally got a chance to take off the passenger valve cover off and I checked out the tensioner on that side and it looks to be in good shape and I dont think the chain is loose, but im not sure how much "play" the chain is supposed to have. Also the timing of the camshafts looks pretty even. Now Im going tackle the driver side....so much stuff to move and take off compared to the passenger side