I've been reading a lot about replacing the secondary tensioners on our x308's. Lately I have stumbled on a post saying sometime in 2002 they fixed the problem and if your x308 had a VIN number greater than xxxxxx you should be good. I have a x308 vdp with 121000 on the clock. I've spent the winter doing preventive and fixing things. Coil packs, shock mounts, Interiour etc. I was ready to tackle the tensioners but I'm treading lightly. Anyway my VIN ends in 40511. Can anyone shed a light before I break it apart. Is mine a factory fix or do I need to look anyway.

Thanks all for helping me.
David

 

F41862 and higher have the updated tensioners. Assuming they haven't been updated in the past, you have the plastic tensioners.

 

My luck at least I was planning on that anyway.

Thank you much

 

With that settled, a word of advise: If you opt to do the secondaries yourself with the zip-tie method, be absolutely sure you rotate the relevant camshaft in such position that ALL lobs are without tension (no valve pressed).

Only in this position you can lift the camshaft, and torque it back without putting stress in it.
Doing otherwise might result into a broken camshaft!

 

If you're just doing secondary tensioners, you need to make sure the flat spots on the cams are facing at 12 in relation to cylinder head position. You're going to need to hold the cams in place, loosen the bolt on the exhaust cam and remove. Take the sprocket out, and you can sneak the tensioner out without loosening any cam caps. Done it this way many many times. However its best to do the whole lot. Have seen primaries fail in the past.

 

Others may beg to differ but renting the tools makes the job very easy and eliminates the risks associated with the zip tie method.

 

Especially as the lower tensioners are most likely cracked as well.

 

The primaries are not subjected to the high temp from the cylinder heads and are likely to last a lot longer.

 

Tell my former tensioners then, that they shouldn't crack They did. As well as the guides... The guides were actually falling apart.

 

I do agree that it is better to have them all exchanged, they might not fail as fast as the secondaries, but their plastics disintegrate in the same fashion.

However, the big difference is that the secondaries can fail catastrophically without warning, where the primaries should (..) start giving an indication by rattling without such catastrophe.

I myself only changed the top ones so far, with the primaries and new chains still in the box ..
Basically because I don't have the facilities to do them all myself, and as I still did not find the person I trust to do it for me.

 

Bought the car at 98k with a rattle caused by the primary guide failing. Secondaries were the original plastic style, with a slight cracking but no obvious failure yet. Not sure if either were replaced in the car's past. That middle piece on the right was fished out of the oil pan. Luckily it was the guide side and not the tensioner side that failed, if it had been the tensioned side then it's possible the chain could have skipped.

 

It's possible the engine had overheated in the past. But I'm not disagreeing with you in that it's better to change everything. If I hear a rattle at startup I will certainly be ordering the parts, but until then I have other things to take up my limited budget.

 

updated style tensioners does NOT MEAN BULLETPROOF!!!

 

Brutal: Have you ever seen any documentation from Jaguar regarding the final metal tensioners?

I was told many years ago that no x308 got the final metal .. only the second generation. When I discussed the August 2001 changeover -- my friend (a long time Jaguar parts manager told me ... no) he even confirmed with the head mechanic that they had replaced many 2002's.

 

From Engine (0108130000) onward.... ALL 4.0 engines had Silent Running Primaries and all metal bodied tensioners!!!!!!!!!!!!!!!! The newer style oil pump was used with the newer chain setup.

bob

 

Yep as Bob states from August 13th 2001 starting with chassis number F41862 all AJ27 were upgraded to AJ27S with the forthcoming stroked 4.2 timing gear and pump. There aren't many compared to prior units but they are about.
The 2002MY in the UK are MY2001 and it'd have to be a late USA MY02 to have that version of the engine. The USA MY03 cars will have them, but they'll be rare as the production in the UK finished summer 2002 with the forthcoming X350 and changeover of factory from Brown's to Whitley.

 

The 02 XJR I bought new has a late August 01 production date -- F45829. My other one is much later .....

41863 was the start of 02 production in 8/01

Got the engine number from the dealer years ago -- In my files ..... someplace.