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07 December 2011

Rover V8 - Critical engine failure from composite valley gasket

I'm bringing this very important failure to all those that have or about to embark on a journey to rebuild their Rover V8's, it relates to the composite type valley gasket, in other words the one that has the black rubber finishing as per the pic below.

What if the above valley gasket ended up looking like the one below after a mere 5 months and 8000km's in operation following a full engine rebuild.


Not pictured here is the oil pick up which completely blocked up, the result was oil starvation and caused severe damage to camshaft and hydraulic lifters.
The rest of the engine was saved as it was shut down immediately due to a flickering oil light.

The 2nd camshaft (with yellow circles) was the original Land Rover part and was as new when the motor was rebuilt, the camshaft to the top of the picture is the new replacement.
Compare the two and you can see just how severe the damage is.

Camshaft and hydraulic failure picked after removing sump to investigate possible oil pump failure, the remainding oil in the sump had a silver shimmer which indicated that something was seriously damaged.

So what happened:
Bad part, simple and to the point, brand in this case is not important and that includes genuine.
While I say a bad part is to blame for the above major failure we do need to consider another factor.
Engine oils, I'm a big fan of Shell oils and always use Shell Helix HX7 (10W40) - Part synthetic
We use this oil in all Rover V8 engines including modern V8s unless a customer specifies a different brand or grade.

Why am I pointing to the engine oil..... but should I.
Todays modern oils have what the industry call "additive package" to make their oils lubricate and protect our engines better, the problem we have here is that these additives can be quite harmful to old technology parts such as the composite inlet manifold fitted to the Rover V8's.

In theory I'm not blaming the oil, after all good quality oil is important and I'm not about to change that policy

Use non composite inlet manifold gasket from a 3.5 V8, yes it is the same port size etc right up to the 4,6
Install as per workshop manual

Non Composite valley gasket.
If gasket is in plastic wrap please remove, its not a sealing agent
Gasket is marked "Front" which must face up and to the front of the engine
If you want it black then use high heat black spray and only do the top (exterior) of the gasket.
You may use a high quality silicon sealant as we do but only around ports and apply to the thickness of lets say cling wrap, in other words very very thin layer and a mere 3 to 5mm in width (Pic to follow)
With immediate effect we will no longer be installing the composite type gasket on repairs or rebuilds.

Brief history:
Engine rebuilt July 2011
Engine failed 3rd December 2011
Engine Oil replaced every 7500km's or sooner depending on condition
Shell Helix HX 7 (10W40) used after 3000km break in period

The worst part about the above failure is it happened to my very own Range Rover, one of two that I own
No doubt about it I was not impressed and it "seems" that this has never happened before....yeah right.

It seems this is not a unknown problem but at the same time not that common too.
Thinking back on past rebuilds I did notice very small sections of the composite in the sump and merely dismissed it for heavy carbon deposits as it was brittle

The reason for the newer composite gasket is noise suppression, the plain steel type is alot nosier as it transmits through it easier