My 2.1 engine which was built by someone in the UK had a small leak from the cam seal area causing the LH timing belt cover to be soaked in oil. Not much at all but a small drip everytime I parked the car.

So I took everything apart to replace the cam seals but they seemed fairly dry to me. I continued to remove the rocker covers and the front camshaft caps. I noticed that sealant had pushed into the oil passage in the upper AVCS cap (EJ207 big port heads), not fully blocking the flow but probably 50% of it.

How do you experienced engine builders apply the sealant to avoid this? I know what the FSM says but I was thinking it perhaps could be better to spread the sealant flat with your finger instead? I guess it only needs a very thin bead of sealant to seal.

 

a very fine bead is all that is required.................

we see quite a lot which are 100% full of sealant!!

 

Be careful and get that sorted seen a couple go up in flames over the head of that. Drips on headers/manifold they in turn soak up the oil in the insulation then all of a sudden a fire. Last one that did it was sitting at the pumps while a man was in paying for fuel. Lucky he had a fire extinguisher in the boot.

 

Thanks, I know how much of a bead is enough from work but we have robots doing it for us (truck engine assembly) and it's not anything quite as close to an oil passage as this. But I'll try to run a very fine bead and see how it turns out.

Yes it's not a good place to have a leak but it was just one small drop that ran from the timing cover/camshaft cap and then along the rocker cover and down to the subframe and later the anti-roll bar. Also I have an OEM twin scroll manifold so an oil leak on the heat shield isn't quite as bad as onto header wrap. But it never leaked onto the manifold and I never could smell any burning oil.

 

One more question, I watched this video , and noticed that he on the smaller exhaust camshaft cap puts sealant all the way on the cap. If I look at the picture in the FSM it seems to suggest to stop halfway around the bolt hole, which is correct or does it even matter?

 

As far as I can see the sealant beads are to help prevent any external leakage.
Going beyond the small cap bolt hole doesn't achieve this aim, (leakge would be internal) so in a "production" senario would be a huge waste of sealant.