Cam Seal Leaking

[Myata]

Had a small leak out of the exhast cam seal, didnt worry about it to much. The other night, i smelt burning oil alot more then normal, and noticed the oil pressure had dropped abit. Pulled over, opened bonnet, and found oil all over the block, head and cross member etc, on the exhaust side. Topped the oil up, drove it 15 minutes home, and parked her up. Pulled the rocker cover, and the casing around front and rear of timing belt, cleaned it up, ran the motor till it got to NOT, found where it was leaking from. Removed old exhaust cam seal, was no scratches or gouges or marks of anykind. Pushed new seal in (did not use sealant, will retry using sealant tomorrow), started motor, and when it was as NOT, it started leaking again.

1990 NA6

Has anyone come across this before? Or is it simply a case of using a sealant?

Any help will be great. Cheers

Jared

[spikes]

are you sure you installed the seal properly? one slightest fold in the lip and it'll leak. did you have to take off the valve cover gasket, it could be leaking from the half moons, you are supposed to seal it up with a bit of high temp silicon.

i just went through the hassle of changing all the seals, no more leaks. replaced front cam seals, front crank seal, rear crank seal, cas o-ring and valve cover gasket. smeared a bit of high temp rtv across all the half moons and its all sweet now

I doubt the cam seal cam spray that much oil around, there is a plate across the front of the cam seals where if a leak were to occur, it would just dribble down the front of the engine block.

[Myata]

Put a new rocker cover gasket on a few weeks back. So that shouldnt be a issue.

Yea, had to remove that cover plate in order to find the leak.

I'm going to try again today, using sealant, and see how it goes

Cheers mate

[zossy1]

This sounds remarkably simple - you just "pushed in a new cam seal".

Are you just making this sound terribly simple? In reality this is a pig of a job that requires the removal of the timing belt and the camshaft/timing belt pulleys (together with everything else associated with that job). I assume that is the seal you replaced, and this is how you did it?

Please, for the love of all things holy, DO NOT use silicone on your camshaft seals. Just don't.

[93_Clubman]

Perhaps OP is referring to the half moon seals.

[Myata]

yea mate, removed timing belt off both cam pullys, removed cam pully, pulled out old seals using screws to grib them and lever out, and then got a 32mm (i think it was) socket and hammered gently till it was in evenly

rocker cover gasket is brand new, rocker cover half moons / cover have no scratches / gouges / marks

camshaft had no marks, neither did where the seal seats

on one of the other threads, he used sealant on the outside half (that sits in the head, not the camshaft)

[zossy1]

The half moon seals shouldn't need silicone either, if they are installed correctly and the mating surfaces are clean.

If you have that much oil coming out, something serious is wrong. Something is pinched, or a seal has dislodged... I daresay something more serious than a little silicone can fix.

[Myata]

Mmm. Going to give sealant and new seals again tonight, and I'll let you know how it goes.

Fingers crossed

[manga_blue]

Quality of new seals is pretty variable. There's some pretty rubbishy stuff for cams and cranks out on ebay. Some that I've seen are so hard that you'd be pretty lucky to get them to work at all. I'd get nice soft ones from Mazda or someone like Mania. Also make very sure that the new seal is not creased or folded during/after installation.

Cam seal leaks are normally pretty minor. If you've still got a LOT of oil coming out through the seals then it may not be the seals' fault. It could indicate there's strong positive pressure in the crankcase and the oil is being pushed out through the seals with the escaping pressure. This might mean excessive piston blow-by or failed PCV or other crankcase ventilation components. What happens if you take the oil filler cap off and hold your hand over the hole while you rev it? Lots of pressure is not good.

Just as an afterthought. I can't remember exactly how the oil supply holes and cam bearings at the front of the cams are positioned. Is it possible to drive the cam seals in so far, or otherwise position the cam, that the oil which is pumped onto the front cam bearing can only escape by being blown out through the seal?

[NitroDann]

I agree with everything zossy1 has to say.

Also, holding your hand above the oil cap hole isnt a good indicator of blowby. Actually its stupid because you can feel the wind coming off the cam lobes.

Heres what you do to test blowby.

Disconnect the passenger side PCV hose. Attach 3 odd metres of garden hose.

Put the other end of hose in a bottle full of water. Drive WOT down the road in 3rd and rev it out. Look for bubbles in the water.

Dann

[Mr Morlock]

how many bubbles are we talking about Dann?

[Myata]

Ok, so today i removed the seal i put on yesterday, and found the spring around the seal was bent on the face of the seal. not sure if that was during installation, or removal.

Put the new seal and sealant on tonight, with sealant on the half moon edges on rocker cover gasket, just incase. Will let it set overnight, and ill update out tomorrow when i start her up

Cheers for all your suggestions

[NitroDann]

how many bubbles are we talking about Dann?

If it looks anything like blowing bubbles in a milkshake thats bad.

Mine makes no bubbles at all. 20,000km old engine, has a very hard life, Much more power than stock. Oem style rings. So a healthy engine should have almost no bubbles.

Dann

[Myata]

yea shes done 300,000 kms, so im not suprised shes having issues. i just want her to live abit longer, so i have enough time to build a decent BP motor n throw her in

will start her up after lunch, see how she goes

[Myata]

And the leak is fixed. Thanks for all your ideas and advice.

Replaced cam seal, and used sealant, and all fixed. Not bad for a 2nd year apprentice yea?