Skoda want £42 for a tube of gasket sealant for the rocker cover.

Normally I'd just use any old gunk: Holts, Wynns, Heinz Tomato.

However, on this engine the top cam journals are actually in the rocker cover, and I'm wary of the thickness between the head and the cover. Does anyone have any experience or advice on what to use, or is it time to bite the bullet and pay the Skoda men for some of their special ointment.

Edit: Engine is 1200 6v.

Edited 11 July, 201214 yr by Serf2ndClass

ive built and engine with silicone before, in fact for two years my sump is sealed with it. I wouldnt ever advocate it, just information.

Well the timing cover and sump use silicone as standard.

The rocker cover sealant is probably silicone too, but I wonder about the viscosity and thickness after torque of the bolts, 'cos it'll clearly affect the cam given that the cam sits between the rocker cover and the head and simply 'pops' out when you remove the cover.

I've got a VW/Skoda workshop manual for AWYs and AZQs at home, so I'll have a look later, but surely if things are as you say, there must be some 'features' on cover or head to make sure that the right spacing occurs irrespective of how much it's tightened down or how fat a bead of sealant is used?

Yeah, you could be right about that. I'll take a closer look at home.

I was mighty surprised when I took the rocker cover off and the cam popped out I can tell you. But that's how it is.

Mind you, it's pretty involved getting the rocker cover off cos you have to remove the timing cover, which means removing the sump and the crank screw and various other bits, including the driver side engine mount.

as long as its left to cure a bit

Let me know if you want any scans of info emailed over, not sure how much Haynes has, or what you have.

The tightening torque of the cover bolts is given as 6Nm + 90° angle. Which is great if you have a torque wrench that goes down to 6Nm! Skoda reckon the bolts should be replaced too, but I'm not sure I'd bother unless they turned out to be refreshingly cheap from somewhere.

Hello again Wino, thanks for your offer.

The rocker cover and cylinder head are both machined flat with cam journals set into them. I can only assume that you're essentially expected to keep the gasket sealant as thin as possible when you torque down. A dry fit with the cam allows a tiny amount of play on the end, essentially enough for a layer of oil. My Torque wrench does go down to 6Nm. It doesn't go up to 90Nm that I need for the crank screw though! I will be replacing all of the stretch bolts as specified.

Incidentally, all of this is due to a 'well know' issue of burned exhaust valves on this engine. Number 3 cylinder has virtually no compression and the valve had a huge crack in it. Cost to replace valve, replace valve guides, and re-seat all valves £250. Anyone know why this heppens? I've heard it said that the 'maniverter' is just too close to the exhaust valves on this engine.

http://www.briskoda.net/forums/topic/226305-skoda-uk-deny-any-problemsgrrr/

Anyway, prices from Skoda for those that are interested as follows (incl VAT):

Headgasket 23.89

Head bolts 55.58

Cam screw 0.88

Crank screw 2.77

Exhaust manifold 5.55

Cam cover bolts (set) 9.23

Engine mount bolts (x3) 12.36

Rocker cover gasket sealant £42

Most of these prices are not too bad.

I've got head bolts from ECP at £20 (Elring, so should be OK).

Probably will pay the £42 for the special sealant.

I'm using my own gasket sealant for sump and timing case, and my own assembly lube.

Sounds like you know very well what you're doing, but just in case, my info suggests a bead of sealant 2-3mm wide. Looking at how adjacent that bead has to run to some of the bearing surfaces, I'd definitely err on the side of thinner rather than fatter. If you want to borrow a 112Nm-capable torque wrench, and you happen to live anywhere near Oxon, let me know.

I've heard, or rather read, about these valve problems on the 1.2s, but don't have any real clue what the fundamental issue is. I did see one post on here I think where valve seat(s) apparently hadn't been machined correctly or installed correctly. That could've just been a one-off, I guess.

Great Wino, Actually I live near Wallingford, but I'm frequently in Summertown.

Loan of a bigger torque wrench would be useful, I've been puting off buying one.

I do know pretty well what I'm doing, I've just never seen a cam arrangement like this before. The journals have a fair amount of scoring on them, but the engineer who did the cylinder head said is wasn't unusual, they're machined straight into the alloy, no linings or shells or anything. Engine has about 80000 on it, I reckon that these little engines are only designed for around 60000, which is terrible in this day and age.

I have the ELSA workshop manual on my PC, so I'm OK in that respect. Definitely need to be careful of the gasket on the cam journals.

Thanks again

Jon

Well ours is on 102K and going strong, so they're not all bad. Admittedly it is the 12v variant, so may run lower combustion temperatures due to EGR-ness, but only when that is operating (and working correctly!).

I'll send you a phone number by PM, I'm only 10 miles or so from Wallingford. Would potentially be interested in a look at your engine while it's still in bits, if I'm not too late.

No problem, I await your message.

You're welcome to come and look at my pile of bits. Won't have all the parts to re-assemble until early next week. (Skoda and ECP special order)

I think (but am not sure) that the cams on the 12v are a very different arrangement, also is the cat in the exhaust manifold as it is in mine (maniverter)? Probably just a much better engine all around.

Yeah, looking at my book, the 12v cams come away with the cover, with some sort of upside-downy camcaps bolting them up into it. :think: :wonder:

It does have the exhaust mani with cat bolted straight on, not sure whether it's exactly the same as the 6v one though.