LR4 PCV Valve Question

[Aderry]

I am replacing the PCV valves on my 2013 LR4 and the kit came with 2 different size springs which do I use?


My issues is when I removed them the one closest to the fire wall was in good shape with a longer spring, but the one closest to the front of the engine the spring was rusting and completely compressed. So is it a combination of long/small or assuming the back one is right, is it two long springs? This is the NA 5.0L

Thanks

 

[ryanjl]

Both mine were the exact same.

 

[Aderry]

Thanks from the picture do you think yours looked like the longer or shorter spring?

 

[Localschauss]

Mine where identical in length and looked more like the shorter of the two you have pictured.

 

[Aderry]

Thanks I wonder if it’s a supercharged vs NA thing.

 

[ceeerock]

Thanks I wonder if it’s a supercharged vs NA thing.

The shorter spring is for the 3.0 engine. I believe the longer spring allows more air in, hence the hissing sound (which is normal)

 

[klillard]

In this case everyone is partially both correct and incorrect. Pulled apart many 5.0 NA PCV valves and the one closest to the front of the motor should have a shorter spring than the rear valve. The rear one applies more pressure (as it is longer.) You can look at the springs closely and tell they aren’t wound the same. The V6s I believe only use one PCV and it uses the shorter one because it has less resistance to flow (smaller spring due to a smaller engine.) Less spring pressure won’t cause leaks due to excessive crankcase pressure on the v6. Put a large spring on a V6 and you’ll cause leaks, but the V8 has to sized for a reason. Not sure of the exact reason just like I’m not sure why they use 2.

The shorter spring is for the 3.0 engine. I believe the longer spring allows more air in, hence the hissing sound (which is normal)

 

[Land Rover Joe]

You can see the springs on my 2010 LR4 which we did a couple months ago.

The springs for the V8 are the same size although I had trouble with the new springs...and had to reuse the old ones....

 

[Land Rover Joe]

Okay...so I was completely wrong.

I had to look into it and sure enough - there are indeed two different size springs in there.

Which explains why I had issues with the replacements I purchased from Atlantic British - I purchased two

PCV Valve Service Kit LR133579, Includes Diaphragm And Cap, For Land Rover LR4, Discovery 5, Range Rover Sport​

Not realizing...that there are actually two different springs, which is why we had to reuse the old springs.

The issue we ran into when we reassembled the engine was a vacuum from the PCV which was making a high-pitched sound with the engine on. After listening around - we realized the problem was with the PCV valves and then went ahead and swapped out the springs.

So @klillard is all over it - you will need two sets but two different springs for the 2010 V8 LR4.

While a bit embarrassed that I completely screwed this up - I am glad I now understand what the issue actually was!

Many thanks for everyone's contributions and @klillard 's notes (it helped me revisit this mystery and solve my longstanding question about those valves!)

Wish someone (or even Atlantic British would have noted it) that the two valves are not identical....

Photos of the new valve covers...with old springs underneath, on the engine attached and now working just fine -