Oil leak valley gaskets, tips and tricks?

Mats Fredsson

Mats Fredsson

Member
Hi, I have a bad leak from valley gasket, both at front and rear, big enough to make severe oil drip marks on ground, and going to replace intake gasket and end strips.
I did som try out with open crankcase ventilation but that did not change anything (my thought was to high pressure in crankcase)

Earlier someone replaced the cam/followers and then also replace the valley gaskets.

Now I bought a set of intake gasket and end strips, (of standard type), and need some smart advices what to keep in mind and how to succed.
 
I don't know what's happened on your engine, but I've never had a problem with it leaking oil from the valley gasket. Have you got the spreader plates on top? The only other thing I do as a preventative measure is some Hylomar around the water gallery connections between manifold and head. The next thing would be as you say is crankcase ventilation, make sure the breather filters are all clear and connected. Check for other sources of leaks ie. sump gasket, crankshaft seals, rocker cover gaskets and timing cover especially around the oil pump and filter.
 
colnerov said:
I don't know what's happened on your engine, but I've never had a problem with it leaking oil from the valley gasket. Have you got the spreader plates on top? The only other thing I do as a preventative measure is some Hylomar around the water gallery connections between manifold and head. The next thing would be as you say is crankcase ventilation, make sure the breather filters are all clear and connected. Check for other sources of leaks ie. sump gasket, crankshaft seals, rocker cover gaskets and timing cover especially around the oil pump and filter.
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I am also surprised by the amount leaking, it is clearly from the valley gasket. I assume that they made some mistakes when fitting, they used some kind of sealant, seems like RTV or similar.
Yes, spreaders are in place.
I have a "sea" of oil at the top of clutch housing, and also marks of oil going down the front of block. (will try to take som pictures)
I've checked all crankcase ventilation parts, from pipes at valve covers, hoses from them to intake incl. frame dampers and ports into carbs.
Also the pipe, hose and filter at the rear of engine to air cleaner.
Rocker cover gaskets are replaced, and not leaking.
 
As your 'sea' of oil is quite high up on the engine suggests it's rocker cover gaskets because they are higher, have you got cork or rubber gaskets?
 
colnerov said:
As your 'sea' of oil is quite high up on the engine suggests it's rocker cover gaskets because they are higher, have you got cork or rubber gaskets?
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As a matter of interest . Are the rubber gaskets a better option under the rocker covers? My cork gaskets aren't leaking , but Im about to remove my R/covers so am looking at the more expensive option.
 
GRTV8 said:
As a matter of interest . Are the rubber gaskets a better option under the rocker covers? My cork gaskets aren't leaking , but Im about to remove my R/covers so am looking at the more expensive option.
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I fitted the rubber gasket for both the rocker covers and the sump on the V8 in the Land Rover 5 or 6 yrs ago, and they are still bone dry. I was advised not to use any sealant and didn't. HTH.
 
colnerov said:
As your 'sea' of oil is quite high up on the engine suggests it's rocker cover gaskets because they are higher, have you got cork or rubber gaskets?
Click to expand...
I did replace those and have now rubber gaskets, but they are not leaking as far as I can see, otherwise there should be oil on the exhaust manifolds. The leak at the back is the same.
 
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At the rear (offside) of the block is a breather fitting that feeds the filter into the air cleaner - is this tight in the block?
 
Hello Mats,

Is the orientation of your engine breather filter pointing downward? That is the correct way to have them.
Check your flame traps and connecting hoses making sure that they are not blocked. Also check the brass pipes on the carburettors and receive them. If any of these are blocked, internal pressure builds and oil will leak from your valley gaskets just as you describe.

Ron
 
The rubber rocker cover gaskets have little steel spacers fitted to the bolt holes to stop you overtightening the bolts and squishing the gaskets out.
Beware !! these like to come out and drop in your engine. They do this when you go to remove the rocker cover next time as the gasket is oilier and floppier than when first fitted.
I use Permatex Ultra on the ends of the intake gasket and rubbers, it does not leak.
 
SydneyRoverP6B said:
Hello Mats,

Is the orientation of your engine breather filter pointing downward? That is the correct way to have them.
Check your flame traps and connecting hoses making sure that they are not blocked. Also check the brass pipes on the carburettors and receive them. If any of these are blocked, internal pressure builds and oil will leak from your valley gaskets just as you describe.

Ron
Click to expand...
All of that is checked, and even when I tried open ventilation (hoses directly to valve covers) the leak was going on
 
In that case you need to take the manifold and valley gasket off and see what's going on under there.
 
cobraboy said:
The rubber rocker cover gaskets have little steel spacers fitted to the bolt holes to stop you overtightening the bolts and squishing the gaskets out.
Beware !! these like to come out and drop in your engine. They do this when you go to remove the rocker cover next time as the gasket is oilier and floppier than when first fitted.
I use Permatex Ultra on the ends of the intake gasket and rubbers, it does not leak.
Click to expand...
Yes, I know what you mean. But they does not seem to leak. No change with the old cork ones or the newer rubber ones, when i comes to the leaks at the back of engine.
 
I've recently replaced the valley gasket and seals (due to a carb swap from SU's to an Edelbrock) and there appear to be two different types of rubber seal with their own different clamps. I don't know if you can mix 'n' match them so might be worth while checking what you've got?
FWIW I use Wynn's black gasket maker on the rubbers and don't have leaks.
 
cobraboy said:
The rubber rocker cover gaskets have little steel spacers fitted to the bolt holes to stop you overtightening the bolts and squishing the gaskets out.
Beware !! these like to come out and drop in your engine. They do this when you go to remove the rocker cover next time as the gasket is oilier and floppier than when first fitted.
I use Permatex Ultra on the ends of the intake gasket and rubbers, it does not leak.
Click to expand...
That is a good tip - thanks cobraboy
 
Update:
I removed the clamp on valley cover, and made the area very clean, and fitted the clamp again.
Since then I drove approx. 60-70 miles, and... almost no leak there! (see pic)
Ok, gentle driving, no full throttle, but still up to 60 mph.
Makes me think:
If the guy who replaced the camshaft, didn't clean the surfaces, and therefore cause leeks?
When I refitted the clamp I maybe tightened a little firmer and pushed down the seal better.
In that case I need to change the seals, clean carefully, and add new sealant (I bought Permatex).
Any thoughts, guys?
 

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Be sure to use something like brake cleaner to clean the surfaces. then the Permatex will stick. You might find the oil is coming out from under the intake gasket, in which case you might want to start over using a new black coated intake gasket - they seal better.
Put a light smeer of Permatex around the coolant passages on the gasket.
 
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