Cam Seals Leaking - Causes/Why
 

All,

My cam seals are leaking on my relatively new engine, we changed them for another new set and they have started leaking again :mad:

It is a V6 Sti engine, I am running a 12mm oil pump so I thought it may be the oil pressure being too high, but I spoke to Rossco and my oil pressure is similar to his.

100psi when cold
80 psi when warm and driving
40psi when idling

Can anyone offer some suggestions?

cheers

Cam seals are atmosphere pressure. The oil pump will not be causing it unless the oil can't return quickly enough. Bolts tight?

id say the seal wasnt seated fully, maybe slightly angled and probably wore through the lip

[QUOTE=tuna;598007]id say the seal wasnt seated fully, maybe slightly angled and probably wore through the lip[/QUOTE]

It's strange, both sides are leaking, first set, now 2nd set leaking. I'd like to think my mechanic knows what he is doing, all brand new seals also...

id say same as above also

[QUOTE=MY00GC8;598011]id say same as above also[/QUOTE]

Every post is above yours. So you agree with all of them?

What are you running as a catch can??

Is it vented back to the intake or sealed??

There's a possibility it is pressure build up inside the crankcase when on boost causing the seals to leak.

^^I'm using one of the AOS's that are attached to the oil cap, same as the Grimmspeed one.

I've had a read of this thread, guy with a similar issue, removed his AOS and the problem was still there, maybe my issue may be the same as his (read whole thread).

[url=http://www.iwsti.com/forums/2-5-liter-litre-factory-motor/202329-drivers-side-timing-belt-cover-oil-leak-ideas.html]Driver's side timing belt cover oil leak - ideas? - Subaru Impreza WRX STI Forums: IWSTI.com[/url]

what grease are you putting on the seals?

How long has the engine been in? Was it built recently? The thread you linked to may be the problem. If the sealant isn't applied properly to the front cam cap it may be the issue.
But both sides? its not very likely
I would think that crankcase pressure building up would cause the rear main to leak too.

[QUOTE=type25;598048]what grease are you putting on the seals?[/QUOTE]

Not sure, I'm running about 23psi so I don't think that is overly high enough to be causing excessive crank case pressure.

I've had other Subies running more boost and never had issues with the cam seals.

Pull out your pcv valve and shake it,(located under throttle body), if it doesnt rattle its not doing its job and needs to be cleaned out with carby cleaner or some other sort of solvent until it rattles when shaken. A blocked pcv valve can blow seals...

If it was CC pressure making the seals leak they all would be(f&R crackshaft,cam covers etc etc)

Most likely its the cam caps not being installed/sealed correctly or having a burr etc. You gotta follow the FSM for correct proceedure etc and its best to use subaru genuine seals.

oil pressure has nothing to do with it either.

Bump

What sort of dollars is one looking at to have this fixed?

I assume you won't be pulling it apart your self, Soyou can't check if the tech has used the correct sealing methodson the seal and the first caps,
Is the car fitted with aftermarket cams?
Has it been leaking since it's build?

Ahh I presume Gav has sorted his in the year since this thread..

I just wanted a approx cost as mine need doing.

[QUOTE=teejay;681461]Ahh I presume Gav has sorted his in the year since this thread..

I just wanted a approx cost as mine need doing.[/QUOTE]

Actually mine hasn't been sorted TJ, we have done the cam seals twice now and I'm led to believe it is the Cam caps that may be leaking.

I assisted the 2nd time and the seals were perfect, we even put some sealer on the seals when we put the new one's back in.

It was a fiddly job, radiator out, covers off, timing belt off, cam wheels off.

Hopefully mine will be 3rd time luck :rolleyes:

if you are mechanicly minded you could do them your selves only problem i see is getting the cam gears off with out special tools. other than that crank seal is very easy to do.

Nope not mechanically minded - can write an essay on how to do it, but dont ask me to do it.

Yeah saw the date after post and thought shit, Gav have you guys ran the thing with the timing covers off to confirm it the outter side of the seal leaking, Might sound dumb had a Mitsubishi with same problem, Machined surface where cam seal ran was under sized and cam required a speedy sleeve to be fitted fitted.

Would be good to coincide this sort of fix with a major service(belt, pump, idlers, seals, hoses etc)

Engine out.
Strip off front of engine.
Valve covers off.
Replace seals/reseal caps.
Reverse first 3 steps.

You would at the same time, f&r main seals, oil separator plate re-seal.... maybe belt idlers wp tensioner etc if need be.

Basic seals fluids & labour... ~$1k many factors to consider.

Yup its what I am going to end up doing.

down the page you can see the issue this guy had blocking the oil track with sealant that leads to the cam seal

[url=http://www.iwsti.com/forums/other-vehicles/189483-sms-eq-tuning-gc8-race-car-build-thread-5.html]SMS/EQ Tuning GC8 Race Car Build Thread - Page 5 - Subaru Impreza WRX STI Forums: IWSTI.com[/url]

bump for a mate

Bump to revive thread

Neil do all of Subaru heads have the oil track or is that exclusive to the AVCS heads?

I'm experiencing leak from the passenger side cam seals. Its really hard to tell but it appears to be leaking where the inner seal meets the camshaft.