npinks wrote:

I thought you should never attempt to tow a 4x4

It begs another question,
It assumes that the engine can be started. If not and its an Auto, how do you get the gearlever from 'park' to 'neutral', I assume there is a hidden feature for this

You should never tow an auto or spec lift (2 wheel tow) a Land Rover, old manual Landies you could spec but you have to remove the prop.

With an auto FL2 that won't start, if you insert the key, press and hold the start button so the ignition lights come on, you can engage N by pressing the brake pedal, this will release the park lock and enable you to select Neutral.

As for mine, looks like the hydraulic lash adjusters have locked and caused the valves to touch, can't see any other reason why the engine now sounds like it does!

Head off time

As a matter of interest, the original oil and filter used in the service was genuine Land Rover, can only think that this has just been a case of rotten luck and coincidence that it happened on this occasion.

"As a matter of interest, the original oil and filter used in the service was genuine Land Rover, can only think that this has just been a case of rotten luck and coincidence that it happened on this occasion."
Something is wrong ! Oil grade ?

According to your spec yours is manual ? there is a lot of talk about yours being auto ?

An engine with jacked up lifters offers no resistance and towing a matter of yards normally to fire

All the cars i used to tow start with jacked up lifters used to fire instantly with a tow.

Did you buy the oil in 1 lts packs ? as my 2 dealers have always said they don't sell 5 lts packs

Are you sure the oil spec is correct ? have you checked your reciept and containers to make sure what you bought and what you paid for match ? sounds very much like wrong oil spec.
I really cannot see what else has occured

She's a manual!

Correct oil grade and yes, it came in 1 Ltr cans. It's certainly baffling me! Tried to give her a short tow this morning but to no avail, engine is flat still with no signs of compression.

I am sure the engine at the top end was starved of oil at first.......after checking the filter (removing it and replacing it for a second time) and checking for leaks, the oil pressure is now bang on, plenty up top with the cover removed whilst checking the cams (turned it over and loads of oil came through).

What confuses me is if the engine was starved of oil and that caused it to cut out, surely it's only the lifters? the engine obviously hasn't seized or overheated as it immediately turned over again on the button, it just sounded flat!

It hasn't jumped teeth on the belt but the only thing I can't check with the head still attached is the valves.

Reckon this is my only option left.....remove the head and check!

Blimey, I would be as worried about why its happened as to whether it could happen again. Did you rev it really hard to try and get the oil light out ?

With the cam cover off , when valves are bent you can often see the lifter sitting lower than usual or in slightly different places . check each lifter when its on the back of the cam.

I havent seen the oil pump to see whether the pressure relief valve is external, if so i would remove to see if it looks like its scored badly and whether it jammed.

The only other extremely unusual cause of an engine turning over without compression can be totally blocked exhaust 1 i know it sounds weird but been there done that.Jack didn't slip and collapse an exhaust pipe ? I know you said it ran momentarily and blocked exhaust that can happen and the pressure builds up and holds the valves open as the engine dies.

If you don't find an explanation I think you need to keep a good sample of oil.

Hello Offroadit,

You are technically switched on and have carefully considered the obvious. Guesses from me are not going to help, but I wish you well in your resolution of this unusual prob'

I would much appreciate it if you would keep us all informed by providing an update when you have a moment on this unusual failure.

Kind regards Toadshall

I'm wondering if an internal oil gallery or pipe has been blocked with a piece coming off the new filter for example? Is the Cam belt tensioner hydraulic of mechanical? If it's hydraulic could the belt have slipped initially and bent the valves?

I don't really know the layout of the valves on this engine but if they sit in the head with an angle perhaps the rims have been bent against the pistons and won't seal. My only experience of a broken cambelt on a BX left me with a broken camshaft as the vertical valves acted on it from below.

I don't know how a jacked up adjuster situation happens. Surely it would be shorter without oil pressure? So that would give you Alex's suggestion of not enough lift, and yes...timing way out so very poor cylinder charge and lack of compression to ignite, but I would have thought you would get some compression at least.

Is there a figure somewhere of what the gap should be below a cam lobe stationary? If it's greater than specified then the valve could be bent/stuck?

If you do get the head off and find bent valves, there must be a reason lurking in there somewhere for the whole thing to happen. Blocked oilways inside? Freelander 1 HSE TD4 Manual in Falklands
Freelander 2 HSE TD4 Auto in Chile

Sorry, request should have read is there, or does anyone know what the gap should be under the HEEL of the cam stationary. Freelander 1 HSE TD4 Manual in Falklands
Freelander 2 HSE TD4 Auto in Chile

The problem has been caused with all 8 of the inlet valve rocker shafts snapping in two! Waiting for new lash adjusters and rocker arms to be delivered to see whether there is any valve damage.....it's looking good tho, all the valves are sitting at the same level so fingers crossed

Some progress at least offroadit!

Sorry guys I forgot about the previous posts describing valve drive system etc. I see 2 adjusters in the system. The belt adjuster looks like mechanical, so perhaps it is auto adjust with an anti-back off system. the chain tensioner is hydraulic, but I doubt it would have enough slack to jump a tooth so I guess the valve timing is still correct?

So maybe the damage was due to too big a gap and excessive hammering whilst getting up oil pressure?

I'm still puzzled because this doesn't happen with everyones oil/filter changes. Something is wrong inside? Is there a non-return valve to keep oil in the supply up to the hydraulic tappets? Did this valve (if there is one) get held open with new filter debris?

If you just fit the new parts will the same thing happen? If it was me, I'd be checking the oil supply to the tappets while cranking before putting it together. Perhaps blow air or squirt oil back down the feed. Anything else? Freelander 1 HSE TD4 Manual in Falklands
Freelander 2 HSE TD4 Auto in Chile

Are you now able to understand the process in detail that led to this extraordinary failure?

The inlet valve rockers have clearly been mechanically overloaded to the point of failure. The question is Why, and why just the 8 inlet rather than all the 16 inlet and exhaust rockers

It is likely that a number of interconnected elements caused this failure. Understanding how many and what their sequence was will be extremely important to all of us

Regards and good luck, Toadshall

I think between us all we have gone over everything that makes valves work. Do you think it was just a simple case of too many revs before the oil pressure got up? Of course there would be a short delay whilst the new filter is filled with oil so one must be patient and remain at idle until the oil pressure light goes out before revving. What do you think? Freelander 1 HSE TD4 Manual in Falklands
Freelander 2 HSE TD4 Auto in Chile

As the intakce camshaft is driven from exhaust cam and the exhaust cam is driven through toothed belt there should be only one reason for this to happen - timing of the intake cam has changed.This can be caused by low oil pressure and therefore not functioning hydraulic tensioner,tensioner failure or camshaft toothed gear or chain failure.Broken rocker arms are just a result of other problem.Check these components carefully and I will keep my fingers crossed for your intake valves....

As the tensioner is acting on the lower part of the chain, if the hydraulic tensioner is failing the intake camshaft timing is delayed.
So there is no way the intake valves can be hit by the pistons, as they will be actioned/opened much later after piston TDC and anyway they will be closed much earlier than the next piston TDC.

Last edited by alex_pescaru on 28th Nov 2012 9:59 pm. Edited 2 times in total