Hi guys, Before I start the strip down and see what the damage is has anyone had an issue with the timing chains just snap or jump off?? 110,000 miles only and the left hand bank (from the front) when you look through oil filler cap there is no chain. It will start and run very lumpy of course but why would it simply happen.

I was almost at a stop at traffic lights when it happened so only really tick over rpm, I had just been doing 70mph on the motorway I guess that would have been worse. I have been told the tensioners are hydraulic anyone else know this for sure? Inevitably I am guessing worst case scenario is bent valves and hope pistons are ok, has anyone attempted to take to remove the heads on a L494?

Any tips or info would be appreciated. Current: 2014 4.4 TDV8 Autobiography 110k miles......will it make the 200k like the Boss did1
Previous: 2007 3.6 TDV8 200k miles (The best, gone but not forgotten)

They do fail now and again on the v6. I think they are similar engine designs

I have seen a couple of posts over the years on the fullfatrr forum (where I am a member as have both a L494 (SDV6) & L405 with the V8 ). I recently rebuilt my 4.4 after a spun big end bearing. I think you will possibly find the cams will require replacing as I have seen spun lobes as they are an interference fit.

When stripped, ideally you want them checked. I know if the belts goes on the 2.7/3.0L the cam caps take the brunt of the damage and valves are usually undamaged, however not sure on the V8. I'd pull the head as a minimum. The hydaulic chain tensioners were upgraded at some point in the SDV8 life as the new ones I fitted when rebuilding mine were noticeably different from the originals. I guess if a chain is going to go it will always be the left bank as the is a simplex chain whereas the passenger side runs a duplex chain and hence is much stronger. Cause may have been low oil pressure allowing the chain to slacken and then snag. The SDV8 is known for operating at low oil pressure on tick over, so this could be a contributing factor.

With regards to cylinder heads, only original thickness gaskets are available as JLR state the heads or not machineable, however I managed to get just 4 thou skimmed off mine and seated the valves by the same amount and it's been fine.

As for removing the cylinder head in situ, I have no idea on this as I had to pull the complete lump out for obvious reasons.

I've put the link to a parts list I did for mine, you will see numbers listed for pretty much anything you need.

https://www.fullfatrr.com/forum/topic68615-15.html

Good luck!

Wow!! Unfortunate for you but a well described operation and the pics are a great help. When you see the front end removed it is quite a shock at how much pipework is involved in these cars!!

Easter weekend is my hope that I will at least be able to understand how much damage has been done. Looking at yours and comments there is a very slim chance there is no internal damage, that's me being really hopeful!!

I am assuming yours is all sorted and running ok now, thanks for the link, knowledge and hope! Current: 2014 4.4 TDV8 Autobiography 110k miles......will it make the 200k like the Boss did1
Previous: 2007 3.6 TDV8 200k miles (The best, gone but not forgotten)

Yep, 2 thousand miles in and running perfectly - thank god!

I guess you need to decide whether to try and do it in situ (topix says head removal is possible) or pull the engine out. I'd say the head and pistons will be ok, cams/valves possible damage. You'll need at a minimum new RH chain and guides and I'd do both tensioners. To do the chain you need to take the oil pump off, which means crankshaft bolt, which you'll need to remove the starter and lock the flywheel as the bolt is v.v.very tight. Oil pump procedure is listed as removing sump to do, but you could possibly get away with leaving the sump on, if not it's front diff out - if that's the case I'd pull the engine as the front end will need to come off anyway to access everything.

If you do pull the engine, it's not much more work once the front end is off, transmisison housing bolts are easy to get to, exhaust just needs to be undone and can stay where it is as it'll drop back enough. I took starter, alternator, Ace & A/C pump off to gain access to the engine mount RH Bolt and LH nut (You'll need to do starter and alternator anyway to lock crank and remove the complete RH engine mount for the timing pin location) (as below).

R/H engine mount needs to come off to get to the timing pin location for when you (eventually) need to time it back up. Fortunately RH chain runs at the front of the crank so you can leave the left bank chain alone completely. To tighten the RH cam sprockets you have to lock the LH cams with the JLR tool, fit the timing tools to all cams and then tighten the RH sprockets.

I can only imagine that the valve covers, turbo and exhaust manifold will be horrible to remove in situ. I'd have to say that if you have the gear to pull the engine, you'll save time in the long run and do a better job as access to the side of the engine bay is non existent.

If you want to chat it through etc. feel free to drop me a PM and I'll let you have my details.

Good luck!

Mike

Thanks Mike, sometimes to much information is sooooo scary!!! It seems regardless of which way I go there is one hell of a lot of work just to get to the chains before even considering changing them.

I am or have never been one to shy away from adversity but at 65 now maybe this is one job to far but as an ex-garage owner I vowed never to let another garage work on any of my cars. I will look over all your info over the next couple of weeks to get it straight in my mind. When Easter comes I may open the bonnet and simply slam it shut again ha ha

Thanks for all your input Mike very valuable. Current: 2014 4.4 TDV8 Autobiography 110k miles......will it make the 200k like the Boss did1
Previous: 2007 3.6 TDV8 200k miles (The best, gone but not forgotten)