The V8 Owners Forum -

"would not work on it because they dont work on cars with LPG"
well I with them there!
Didn't realise it was on LPG, burnt out exhaust valves are worth an investigate.Have you done a compression test? be worth it, do once by just pulling the plugs out and doing each cylinder in order then squirt a bit of oil in each pot and do it again, if one is very low comp and it stays that way with the oil squirted in then odd on it is a knackered exhaust valve.

Can you not work on it yourself a bit? at least the exhaust gaskets on a RR are pretty easy to do, it will be sunny on Saturday, you could have one bank done in under an hour and there is enough room on a RR to do it without skinning your knuckles (unlike Ian's ford!).
The garages wanting to change you for changing the block know that doing so should fix the problem, even if it is the exhaust gasket, because the gasket will be replaced when they replace the block and either way they charge you for the block, and if they come across burnt out exhaust valves well bonus they can stick 2 heads on the bill aswell.
Best regards
Mike

One more question, is this engine from the time that RPI were flogging top hat linered blocks, or Coscast blocks, just you may already have a top hat linered block.
Best regards
Mike

RPI said the engine number is not theirs so not sure of its origin. All I was told is it was fitted approx 40-50,000 miles agowhen the car was at 80,000

Changed the exhaust gasket, still clonking loudly.

Just gotta find a new block I can afford

Can you run the engine on petrol only to see if this noise remains constant??

I only mention this because a friend had a similar tappety noise on his lpg V8 and it turned out to be a faulty injector. And it was made by Renault ??

I am about 15 mile from bicester on the A421 towards MK if you want another pair of ears on the job ?

Perry

Hi guys,
I have exactly the same noise on my 5.0 RV8 which I have ignored now for about a year. It happens when the engine is running slowly at close to 100 Degrees in traffic (Rad and fan too small). I have 2 theorys on it.
The noise is at the rear of the engine and my first theory is a lazy follower which because of it's location does not see much oil pressure due to pressure losses along the gallery.
The second possibility is a loose liner which at low revs could be following the piston movement.
I have no plans to whip the heads off at the moment as a rebuild is not far away but selfishly I am very interested in the outcome of this thread.

However, removal of the sump is not such a mammoth task and I may be able to detect a loose liner from below.
Regards Denis

Hi Perry,

its the same on petrol. That very kind of you to offer to have a listen. Let me know and I will pop it over your way. Im in Banbury

The slipped liner syndrome was very common in the last of the rover V8's from landrover (the 2003 and 2004 discovery) but not so common in the P38's I believe... I have a 'slipped liner' block in my garage, along with the headgaskets and the deep circular rings puched into them by the liners moving up and down (middle two cylinders on LH bank IIRC).

The tell-tale sign of the loose-liner is that the engine is quiet when cold, but as the operating temp gets upto 80-degrees C then the tapping start quietly, and gets proressivly louder as the engine gets to full temp, to the point that you have to shut it off at the drivethrough to hear or be heard.

It doesn't usually sound like a rattle though, more like a bad tappet with a 1/4" gap - except the sound is 'deep' in the engine.... It sounds just as bad from underside as the top-side. Also, putting a stehoscope or listening tube over the rocker box(es) doesn't identify as clearly as when you do indeed have a bad tappet. It also sounds kind of like a bad big-end bearing - except you know it's not as you can drive for thousands of miles with it rattling away.

It also gets 'quieter' after 1500rpm, and by 2500rpm you can bearly hear it - it just sounds like a very faint tappet noise.

Another misconception is that 'loose liner syndrome' is accompanied by water-loss: my 2003 never lost a drop of coolant in 8000 tapping miles before I pulled it down to swap out the block.

As I said though - the 60-thou-deep grooves punched into the firing ring that are the same diameter as the top of the liners can only be casued by one thing if when you look at the engine, the liners are perfectly flush with the deck - every loose-liner engine has these grooves.


What to do? Well - if you have the tools, and a spare vehicle, I'd take it off the road and do like i did: Order a new top-hat block from V8D, along with a new set of BE shells and mains, and a new set of rings, and rebuild all your moving parts into the new block. Add a set of ARP studs to the party, and you have a good, solid engine.

If you have less than 2000 miles on your cam, you could probably re-use the cam and all the lifters without any ill effects (keep lifters in the correct order though). But if you buy a complete replacement engine then they become paperweights!

ojika wrote:Hi Perry,

its the same on petrol. That very kind of you to offer to have a listen. Let me know and I will pop it over your way. Im in Banbury

I'll be in my garage all weekend tinkering mate.
I'm in Buckingham about 15 mins drive from Banbury services on the M40 J10.
So not many miles away eh?

PM me your phone number and I'll let you have the address.

Pel

its not allways the block, generally if these engine produce a knock when they are warmer there is a good chance it is going to be piston pin to piston or even little end on rod, a worn big end bearing or liner moving up and down, either way best solution is to strip the motor before you buy anything or you may be buying the wrong parts.

Cheers for the input guys , had another couple of opinions , mre pointing to the liner and one saying it could be a little end, so the same as you guys are saying. Got a mate going to take the head off for me in a couple of weeks to have a better look and had a good quote from TVR to put top hat liners in my existing engine . So once the heads off to diagnose it I will have a reasonably priced way forward