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Home > Technical > 4.2 Supercharged Timing Chain Tensioning

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dhallworth

Member Since: 13 Aug 2015
Location: Glasgow
Posts: 40

4.2 Supercharged Timing Chain Tensioning

Hi Guys, hoping that some of you might be able to help me here

I spent yesterday afternoon replacing the timing chains on my 4.2 SC prior to finishing reassembly.

I started with everything laid out on the toolbox so I could identify things as the tensioners for the secondary chains are sided.

Click image to enlarge

After that I pulled up the manual and set about following the process for setting up the timing to a tee.

Click image to enlarge

Following the manual made it very straight forward!

You put the secondary chains on the sprockets then put the sprockets on the cams and put the new bolts into the cams whilst leaving them loose so the sprockets can turn. Once you’ve done this you pull the pin out of the secondary tensioners.

You then build up the LH and RH primary chains by installing the guides, then installing the chains, then you add the guide for the tensioners and then you fit both tensioners. Once this is done you pull the pins on these too.

Once you’ve done this lot you use the special tool from the timing kit to hold the exhaust sprocket stationary whilst you tighten the inlet sprocket bolt to 20nm, then a further 90 degrees. Once the inlet sprocket is tight you do the same for the exhaust sprocket, and then repeat for the other cylinder head.

It was very simple and went without a hitch. I then removed the timing tools that lock the cams, lifted the car up and then pulled the pin out of the flywheel.

I then spun the engine over by hand. 1 x 360 degree rotation of the crank is only a 180 degree rotation of the cams so I spun the crank round 8 times which is 4 complete rotations. Everything moved very freely and felt lovely when turning it by hand.

However, and unfortunately with this car there’s always a “However” 😩… the cams and crank were slightly out of line when I went to repin them.

So, everything was removed and the process was started again following the workshop manual, again, to the letter. The results were the same

These tools should sit flush with the heads. One side was nipped so it was flush, the other side wouldn’t sit flush.

LH:

Click image to enlarge

RH:

Click image to enlarge

Flywheel:

Click image to enlarge

Has anybody done this before? Is this normal? I was expecting the cam locking bars to fit straight on and be flush with the heads and for the crank to pin straight away.

I’ve only ever worked with belts before, never chains and every time I’ve spun them after setting the tension the pins have always slid in perfectly. I just don’t know if I’m expecting something that won’t happen with this car.

Any help will be appreciated!

Thanks,
David. 2002 Range Rover 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

Mon Aug 01 2022 9:05am

Andy K

Member Since: 18 Sep 2015
Location: GL
Posts: 4983

2005 Range Rover Sport TDV6 HSE Rimini Red

I've not done this before, but some thoughts.

Are you saying one cam is out of alignment (per side)
or the cams and crank are not timed as well as you would like ?

Personally I would have had the bottom and top ends locked while fitting the chains. I don't know if that is possible.

I know the diesels have one or two red links in the cam chain and these are meant to align with square marks on the cam sprockets

The other option is to move it one tooth and see if you get a better result

Mon Aug 01 2022 11:17am

dhallworth

Member Since: 13 Aug 2015
Location: Glasgow
Posts: 40

The crank was pinned with the tool as per the manual whilst it was set.

On the petrol engine you fit the chains and tension them whilst the sprockets are loose on the cams so that all of the tension is taken up prior to torquing the sprockets.

You then tighten the inlet cam to 20nm, followed by another 90 degrees and do the same for the exhaust cam then repeat for the other cylinder head.

Everything up until this stage goes perfectly. When I remove the bars from the cams and take the pin out of the crank everything looks fine.

When I spin it over by hand I'd expect to be able to pin it again without any movement but this just doesn't seem to be the case. It's very strange.

David. 2002 Range Rover 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

Mon Aug 01 2022 11:28am

Andy K

Member Since: 18 Sep 2015
Location: GL
Posts: 4983

You are missing tension from the oil pressure. Whether this makes a difference I don’t know.

Out of interest, does the manual tell you to rotate twice and recheck alignment. (I know it gives confidence)

Mon Aug 01 2022 12:21pm

dhallworth

Member Since: 13 Aug 2015
Location: Glasgow
Posts: 40

I think you’re right.

I spoke to our local JLR specialist today who said that this is normal until oil pressure has built in the tensioners. Anything up to around half a tooth is acceptable so I’m going to check it once more but believe I’m good to keep going with reassembly.

Once you’ve torqued the sprockets the manual stops. There’s no further steps in it so maybe I don’t need to turn it over. 2002 Range Rover 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

Mon Aug 01 2022 6:11pm

dhallworth

Member Since: 13 Aug 2015
Location: Glasgow
Posts: 40

Just to close this out…

I had another look at it this evening with a fresh pair of eyes after having slept on it and spoken to the Jaguar specialist.

His advice was spot on, with the tension set and it turned over by hand it’s less then half a tooth out

Will continue with reassembly tomorrow now.

David. 2002 Range Rover 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

Mon Aug 01 2022 8:10pm

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