Author Topic: Replace your PVC valve if having issues  (Read 112 times)

Offline el_freddo

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Replace your PVC valve if having issues
« on: February 01, 2019, 11:27:03 PM »
So I had a massive pinging issue with my EA81 brumby when ambient temps were near 25*C.

I decided to replace the PVC valve as this was probably never done. When I pulled the old one out it seemed to work fine and almost put it back in but decided to put the new one in since I’d removed a pile of stuff to get to the old one anyway.

Result?  Massive difference!  One the recent 45*C day here, I was able to drive around with very little detonation occurring. There were a couple of situations that it could be induced - but it was nothing like the detonation I used to get. Very happy!

So if you’re having an issue like this, look at swapping the PCV valve with a genuine unit.

I reckon the rest of my issue is in the carb’s shaft play.  We’ll see what happens there in time.

Cheers

Bennie

Offline Tas75

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Re: Replace your PVC valve if having issues
« Reply #1 on: February 04, 2019, 10:05:49 PM »
What do you think the new PCV valve is doing?  The EA81 besides being on the low power side they keep going even on only two cylinders for 300kms.

Offline el_freddo

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Re: Replace your PVC valve if having issues
« Reply #2 on: February 26, 2019, 10:08:35 PM »
What do you think the new PCV valve is doing?  The EA81 besides being on the low power side they keep going even on only two cylinders for 300kms.

The EA81 is bullet proof and one of the best engines Subaru produced, only proceeded by the EJ22.

As for the PCV valve, I reckon the new one is closing properly and not allowing excessive crank case oil vapour into the intake manifold when the engine is under load and in light throttle positions.

But I reckon I've still got a vacuum leak - and it could be an intake gasket on the RHS head.  I need to investigate this more.

Cheers

Bennie

Offline Phizinza

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Re: Replace your PVC valve if having issues
« Reply #3 on: March 14, 2019, 08:02:25 AM »
Interesting. I've never heard of anyone replacing a PCV for this reason but it does make logical sense that it would effect predetonation.

Offline el_freddo

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Re: Replace your PVC valve if having issues
« Reply #4 on: March 14, 2019, 09:50:21 PM »
Interesting. I've never heard of anyone replacing a PCV for this reason but it does make logical sense that it would effect predetonation.

Hey Phiz,

While it's certainly helped it's not completely solved the issue.  I'm now wondering if I've got a compromised inlet manifold gasket that's letting air into one bank, leaning out the air fuel mixture.

It's still getting me around town without an issue so I'm not really phased at the moment.

I'll keep this updated as I work things out as they happen ;)

Cheers

Bennie

Offline el_freddo

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Re: Replace your PVC valve if having issues
« Reply #5 on: August 07, 2019, 10:54:57 AM »
Update on this one - it's not the PVC valve, it wasn't an inlet manifold gasket. I think I just need to suck it up a realise that this engine is probably consuming oil or running rich, I'm not sure which one. No blue smoke so it's not loads of oil.

Rings are possibly toast since the engine sat for a number of months with the sump and crank case full of water...

Cheers

Bennie