Hi guys.

OK so I did a few repairs to my Magna last night (Exhaust mid section replacement and rocker cover seal swap), don't you just love the 2am finish! couldn't leave it unfinished Lol :nuts:

Unfortunately it was the rear cover that I had to do, bit of a pain in the arse that's for sure.

Never realized how brittle the old seals were until I tried to remove it, came off in pieces and was a pain to get out of the rocker cover seal channels without damaging the rocker cover itself :shock:

Anyway a couple of questions if OK?

I bought a brand new tube of Sikaflex, only to find most of it had set inside the sealed tube, so I couldnt use any to put a small retaining seal between the rocker cover and new seal, to hold it in place whilst I dropped the cover onto the engine.

The seal was a bit loose and kept dropping out while I was positioning the cover into place, is this normal?

Anyway, I tightened all of the bolts down using the diagonal method, to try to bed the rocker cover down nice and flat, and the seal seems to have compressed nicely uniform all the way around, but will it seal OK without any form of sealer added?

I also took out the spark plugs from the rear bank of cylinders, all looked nice and brown, all the same, no damage visible to the insulators etc, so I put them back (Forgot to get new ones before I did the job, I need to do the timing belt and water pump / pulleys soon so will do them then I reckon.

When I looked into the intake ports I noticed quite a bit of carbon build up down there, the motor runs really sweet with no noises on startup, and no smoke at all out the back, the car has 260,000 kms on it.

I want to use something like Redex to flush out the carbon deposits, or something equivalent (Any suggestions?), but have read that if you do that, sometimes you then can get issues with the motor burning oil as the valve seals are now more exposed and hence you then may need to redo the valve seals, is this right?

Dont want to go mental flushing all the carbon out if it is not causing the engine too much grief, if I end up having to go more hardcore with a top end rebuild!

What do yuo reckon?

Cheers

don't use any sealant for the rocker cover, will seal without it provided it was done right, as for using things like "redex" I found something a hell of a lot better and have been using it for donkeys years (suberu) yes like the car, but this is an upper engine cleaner. your local suberu dealer, or Nissan dealer should carry it.

Hi guys.

OK so I did a few repairs to my Magna last night (Exhaust mid section replacement and rocker cover seal swap), don't you just love the 2am finish! couldn't leave it unfinished Lol :nuts:

Unfortunately it was the rear cover that I had to do, bit of a pain in the arse that's for sure.

Never realized how brittle the old seals were until I tried to remove it, came off in pieces and was a pain to get out of the rocker cover seal channels without damaging the rocker cover itself :shock:

Anyway a couple of questions if OK?

I bought a brand new tube of Sikaflex, only to find most of it had set inside the sealed tube, so I couldnt use any to put a small retaining seal between the rocker cover and new seal, to hold it in place whilst I dropped the cover onto the engine.

The seal was a bit loose and kept dropping out while I was positioning the cover into place, is this normal? Yes. The rocker cover gasket is loose and rubbery. When you press the rocker cover gasket back on, it will form a seal just fine.

Anyway, I tightened all of the bolts down using the diagonal method, to try to bed the rocker cover down nice and flat, and the seal seems to have compressed nicely uniform all the way around, but will it seal OK without any form of sealer added? Yes, there is no need to use any sealer. If you do, it should be just small dabs.

I also took out the spark plugs from the rear bank of cylinders, all looked nice and brown, all the same, no damage visible to the insulators etc, so I put them back (Forgot to get new ones before I did the job, I need to do the timing belt and water pump / pulleys soon so will do them then I reckon.

When I looked into the intake ports I noticed quite a bit of carbon build up down there, the motor runs really sweet with no noises on startup, and no smoke at all out the back, the car has 260,000 kms on it.

I want to use something like Redex to flush out the carbon deposits, or something equivalent (Any suggestions?), but have read that if you do that, sometimes you then can get issues with the motor burning oil as the valve seals are now more exposed and hence you then may need to redo the valve seals, is this right? You can use carby cleaner to get rid of these carbon deposits. It should make your idle a bit smoother

Dont want to go mental flushing all the carbon out if it is not causing the engine too much grief, if I end up having to go more hardcore with a top end rebuild!

What do yuo reckon?

Cheers

A couple of comments in red. nothing too detailed.

Redex is a fuel additive, right? Don't forget fuel first hits the engine at the injectors, it will do naff-all for any carbon build up in the intake manifold before the injectors. Valve stem seals are on the oil side of the heads, not in the actual air flow, so any fuel additive won't affect them.

Most people would do the rear rocker cover gasket, tube seals and plugs all at the one time, but you need to have those parts handy I guess.

Cleaning the throttle body with carby cleaner might be a better idea, but don't use so much the engine gets a mouthful of dirty cleaner. Wipe it off with a rag instead.

Brown spark plugs indicate your engine is burning a bit of oil, by the way - to be expected at that km. Not a problem if the 3 plugs are even in colour.

The rocker cover should be re formed so the gasket is a tight fit and does not try and fall out, if it falls out the cover will not hold the seal properly when fastened down and will leak again

Ah yes, Redex is an additive to the fuel, I remember now, been a long time since I used it, will check out suberu and if not will use some carby cleaner on the Throttle body.

There was a fair bit of oil down the rear manifold, probably accounts for the smell of burning oil after a run, especially as I never see any smoke out the back, even on cold startup.

I did do the plug seals too, I bought the kit from you actually Madmagna via EBay, so thanks!

Not good Madmagna Re: The seal not retaining in the rocker cover = possible warped rocker cover, the seal mostly sat pretty, only the upper long edge of the cover had the seal drooping when being dropped in, I was very aware of making sure I tightened diagonally / evenly when torquing up the bolts, and did not crank the bolts down, nice and gentle.

I never knew that a brown spark plug indicated the motor was burning oil, something to remember for the future, the engine itself sounds nice and tight still, cold starts are fine, no smoke out the back, good power etc, will monitor oil consumption now the seal has been sorted.

Thanks again boys.

LOL just went and did a search on how to read spark plugs, after reading the comments here, check this out:

http://www.superstreetonline.com/techarticles/130_0703_reading_spark_plugs/

The second to last picture and description cracks me up! ......

" If your plug looks like this, you've got more problems than you could possibly imagine. Go find a good mechanic to further diagnose your engine issues...."

Hahaha! Piston to Spark plug contact anyone!!?? :woot:

just for reference . lol

http://4.bp.blogspot.com/-j0zzs4Ml8NE/TgNu2KPVUAI/AAAAAAAACt8/Z--jY0NwoDs/s1600/Spark+Plug+Reading.jpg

I changed my rocker seals the other week.
When I change mine, I do the same thing everytime I change them.
Air intake is removed, including the trottlebody. This gives you alot of room for the rear bank.
Once the covers are off, they get a degrease to remove any carbon build up.
Then, new tube seals go on, I always change the tube seals regardless of condition.
When the covers are clean and dried, I place the new gasket seal on. I don't use any sealant.
Then using a medium sized soft mallet, I lightly tap the inside edge of the rocker cover just enough to hold the gasket in place.
Cover goes on, bolts are put back on, only a few turns to hold it in place. I then take a quick pic of the rear bank, I do this because I can't see the gasket on that side. Then do up from the inside bolt out. I only do each bolt a few turns at a time. I keep doing this till the bolts are done up.
I do them up hand tight, by that I mean, using a small ratchet and don't need to do them up like other bolts. Just enough so the covers are flat against the head and the seals aren't showing.
Do them up too tight and you start bending the cover and you won't get a good seal and it will leak.
Then everything goes back on, car is started and idled for a good 10-15min checking for leaks, then a quick trip to the shops and back. and while idling, go over the engine looking for leaks.
If you do see smoke during the idle, don't panic, it is more than likely a small amount of oil burning off that had dripped when removing the covers. Use a camera to get behind the rear bank and take pics and video to check for leaks. If a leak is found, recheck your work.
Main causes is the gasket has pinched, bolts not tight enough or the cover has warped. I have a spare gasket lying around if it has pinched.

Thanks Grelise, next time will definitely try to seat the seal using your method.

Thanks for the Spark Plug reading chart MadMax, awesome.

Thanks for the Spark Plug reading chart MadMax, awesome.

I think I've seen most of them come out of one car or another (or 2 stroke lawnmower) over the years. lol Haven't ever seen one where the piston hammered the plug though.

I think I've seen most of them come out of one car or another (or 2 stroke lawnmower) over the years. lol Haven't ever seen one where the piston hammered the plug though.

Yeah I'm thinking Big end failure..... Would have made a nice BANG as it hit ......