Landrover Discovery 3 (4L V6) - Timing chain tensioner
 

Bit of a long shot, but does anyone know the location of the timing chain hydraulic tensioner on a D3 4.0L V6 (Cologne) engine? (see image of part attached)

Kevin that LOOKS like the one for the LH bank. I think it goes at the front of the cylinder head, from the inside of the the 'V', high up just under the gasket face for the cam cover. I hope the picture attachment works.

If it is the RH one, the cam drive is at the back of the engine. so the tensioner is on the outside of the 'V', again high up at the back of the cylinder head, just under the face of the cam cover.

Already changed that one, very easy apart from following a YouTube video that said to remove the inner wheel arch for access. Turns out it's very easy to do from above the engine!



Thanks for the diagram of the other one. I had looked there but couldn't see it. The diagram below suggests it might be lower down on the RH side of the front of the engine.

Are you looking for a tensioner for the chain which drives the jack shaft ?

If not, the tensioner for the LH bank is definitely as shown in the drawing, high up on the inside of the 'V', front of engine.

Thanks JD, you're right! That's where it is. I was looking above the intake manifold, but it's beneath it. It looks like I only have to remove the air intake to get at it. Praying that will cure the rattle. I've already got the timing chain kit in case replacing the tensioner doesn't silence it, but that's a much bigger job!

Best regards,
Kevin

Good luck with that Kevin !

We've never actually seen a Land Rover with that engine here in UK as they weren't sold in Europe (only 2.7 Diesel and 4.4 here at that time).

Thor,
Just as an aside, do you know why there is some prevalence for the 3.0L diesel engines in D4 to seize?

A friend here in Melbourne had his seize recently and remarkably Landrover replaced the engine free of charge (I say remarkably because he had done 173,000 km!). He had to pay for the labour but he's very happy and relieved! He believes LR did this because he bought the car new from an authorised dealer and had it serviced by them, on time, religiously. The dealer made a "good will" claim on his behalf.

He now wants to know what he can do to avoid it happening again.

Strictly speaking my knowledge on this particular point is confidential, but loosely, there was a reliability problem with the way the bearing shells were located for the 2.7 and early 3.0 main bearings. The bearing shells can rotate, and then they obviously cut off the oil supply to that bearing and the adjacent crank bearing. Various fixes were tried unsuccessfully, but a revised location system was implemented about 5 years ago, and it has been implemented at the place where the remanufactured engines are done as well, so if you buy a replacement engine from the dealer, whether new or 'recon', it SHOULD have the reliable bearing arrangement. So it is highly unlikely that it will happen again.

Well there was no way that tensioner was going to come out without removing the intake manifold, which is a time consuming job, but I got it off today. I was disappointed to find that the hydraulic timing chain tensioner is very firm, which suggests that may not be the problem, although I have replaced it anyway.

After further consulting the workshop manual (which I remembered I had bought years ago on a CD/DVD), the intake manifold also has to come off to change the timing chain cassette, so I may as well do that now while I have the manifold off.

There are a couple of concerns.

1. The workshop manual says to discard and replace the torx head bolt that holds the timing chain sprocket to the camshaft. But JLR (jaguarlandroverclassic.com) have told me that the bolt is no longer available!

On installation the bolt is torqued to 45 Nm (33 lb.ft), then a further 70 degrees, so presumably they assume the bolt will have stretched, which is why it should be replaced. But what do I do given that it is not available? The only thing I could think of is using a strong threadlock glue on installation.

2. The other issue is that the workshop manual procedure calls for a special Crankshaft rotating tool 303-674 ; JLR have said they do not sell service tools.

Ideas/suggestions welcome!

Yes, all very frustrating !

On that bolt, maybe add some medium-strength loctite and torque it up and then turn a further 20 degrees or something. Should be fine.

Under European (EU) and under USA law, OEM are obliged to either sell special tools or to make the designs for special tools available so they can be made by others. This is 'right to repair' law. I don't know how Australian law stands. If you want to buy the special tool, we should be able to get one here in UK and sell it to you, or get an American friend to find one.

Even though they are obliged under law to make these tools available, most OEMS try very hard not to, and it is only in USA that they don't risk the litigation so the USA is the most likely place to 'easily' find the tools.

If you would like me to try to get one here it would be done through JE Engineering Ltd. so we'd have to set up an account, etc.

Thanks very much for this Thor. I have realised that I was looking at the wrong sprockets and chain in the workshop manual and the job I was planning to do is much bigger than I thought, requiring removal of the LH cylinder head and a significant set of special tools. I don't have the facilities to embark on something like this at home. So for the time being I'm going to simply replace the hydraulic tensioner and re-install the intake manifold so I get the car started and re-assess at that point. Although while I have the tensioner out I will take the opportunity to see if I can use an endoscope to assess the condition of the timing chain cassette.