What kind of sealant for the cam cover?

Post by **BlackBart** » 05 Jul 2018, 11:39

^^ yes! I had assumed the idea with a thin roller was to make sure nothing gets in those grooves and oil passages, so that's a good reminder. Is it better to apply sealant to cam cover surface or head surface?

Should I replace the o-rings at the spark plug holes? I'm thinking it should all be new.

Post by **abscate** » 06 Jul 2018, 03:12

I’ll search for the thread by prwood where he describes doing this job twice, IIRC.

Post by **erikv11** » 07 Jul 2018, 08:14

Apply to either surface, it doesn't matter for sealing, but I like to apply it to the head because that piece isn't moving around. Then put the cams in with just a bit of lube on each lobe, then drop the cover down. It's fine to re-use the spark plug tube rings if they are little-used and come clean on removal, if you are able to get the old sealer off. But they don't cost that much either - your call.

Post by **erikv11** » 07 Jul 2018, 08:16

oragex wrote: ↑05 Jul 2018, 09:23 Not sure about the cover, but for the head gasket it takes anaerobic sealant. Here's why

Just to clarify, that's not the head gasket, that's the cam cover seal (which has no gasket). And that's more anaerobic sealer than needed.

Post by **jimmy57** » 07 Jul 2018, 11:29

Original sealant is the anaerobic stuff. Apply to one side, the side with no dowela. Roll it with a short knap roller or the foam version. Thin coat of paint thickness is best. Stay away from cam bearing bores 1/4 inch so the sealer is not in the bearing area. Clean the sealing faces well and then wipe down with brake cleaner or acetone. The sealant uses the copper trace amount in aluminum alloy as a curing agent so the metal must be clean.

High torque/hard RTV is likely OK as that is what is used on the newer Volvo engines in the same exact place for heads and blocks made the same way. The sealant also acts as adhesive so the old black, blue, red RTV formulas are not as strong and will likely leak in time if used. WHen RTV is used it is not applied with roller. Cut the tip to the smallest hole and apply in a single 2mm wide bead. With that amount ample will squeeze out. Apply RTV with surfaces prepped just like you would fr anaerobic and then apply sealer and immediately assemble. You do not want RTV to skin over so that it adheres to both sides for strongest adhesion level.

Post by **prwood** » 07 Jul 2018, 15:12

Yup, permatex anaerobic sealant. Applied with micro-sized foam roller to give the most even results. I recommend to get the thinnest foam roller possible because I once used a thicker one and I feel that a lot of sealant was wasted being sucked up into the foam.

Post by **prwood** » 07 Jul 2018, 15:15

Also make sure every mating surface is super duper clean before applying it. Recommend using gloves to handle cam cover so that you don't accidentally get finger oils on the fresh sealant. Another gotcha is that I had accidentally left a small amount of oil sitting in the rings for the spark plug tube seals, and when the cam cover compressed on, it squeezed out the oil which contaminated the sealant and led to me having to do the job again.

Post by **BlackBart** » 08 Jul 2018, 21:43

Invaluable information everyone - thank you.

I just received my UK paper manual, so I'm no so completely in the dark now!

I have everything on the cam cover loose - 42 bolts plus ground strap. Funny, when I broke the bolts loose, I got a little POP from most of them - sometimes a few seconds after I had left that bolt.

Didn't realize the VVT solenoids have to came off, so I'll need gaskets for those. I'll get new O-rings as well.

Question - I can get the cam cover to lift up about a centimeter before it hits an obstruction or gets hung up on something. The cams are both loose and will lift up with it. The timing gears are still on. I'm taking my time, no hurry, I'm not going to force anything or lift it up with the factory bar set-up and break something. I've looked all around it with a bright light and a mirror, I can't see where it's hitting, unless it has something to do with the timing gears hanging up underneath on the lower plastic timing cover or somewhere on the front cover ..? It seems to be a metallic "clunk" when it hits.

Post by **prwood** » 09 Jul 2018, 16:14

If you don't remove the timing gears before removing the cam cover, some of the screws holding the timing gears on to the cams can get caught up on the cam cover or the cylinder head prevent them from fully lifting away. I took a careful look at them and loosened up just the ones that were preventing full movement.

FWIW, I also had a similar problem when I had missed removing one of the many screws. So double check just to make sure they're all out.

Re: an earlier post, Volvo's instructions specify to apply the sealant to the underside of the cam cover and not to the head. If I had to guess, I'd say this is for the following reasons:
1. You can easily take the cam cover out and put it on a workbench or other clean and proper work surface to make the job easier.
2. There's less chance of the sealant dripping into the head and gunking things up if you apply it to the cam cover.

Post by **prwood** » 09 Jul 2018, 16:19

BlackBart wrote: ↑05 Jul 2018, 11:39 ^^ yes! I had assumed the idea with a thin roller was to make sure nothing gets in those grooves and oil passages, so that's a good reminder. Is it better to apply sealant to cam cover surface or head surface?

Should I replace the o-rings at the spark plug holes? I'm thinking it should all be new.

Also, definitely replace the o-rings. I paid to get the Genuine Volvo kind. It was relatively inexpensive peace of mind considering they're pretty important for controlling oil flow, and I didn't want to have to go back in and replace them any time soon.

What kind of sealant for the cam cover?

Re: What kind of sealant for the cam cover?