Head gasket removal- timing chain question

I would say 'Im glad Im not the person here recommending people don't use gaskets...'

Go and order a timing cover gasket from Renault and see what -they- tell you.

All the gaskets are available and much cheaper from Volvo, FWIW.

Well, we ended up making a bracket to maintain chain tension (we couldnt figure out how to remove the head without making the chain slack without doing so) but ran into a new problem with the positioning dowels inside the join between head and block.
These are little tube-shaped things that using a 'suitable tool' you are supposed to tap down into the block. Knowing whether or not youve been successful is very difficult to say and the head is resisting being tapped off. Given the potential damage that I could do wedging the head off, has anyone facing this problem found a way round it?

Don't knock them down into the block !!!! You'll really struggle to get them back up .There's a 3mm hole in the block side beneath the split bush to set the height on assembly .
Give the heads a good old whack from the sides with a rubber mallet to break the seal and lift off .This may mean the liners move a bit but it's the lesser of two evils .

I second what Lee said - I've done HG's many times and only ever shifted a liner when I accidentally turned the engine while the heads were off. I've had the liner straps since then!

Ha ha ok! I was afraid to whack it too hard for fear of shearing the little bastards and/or moving the liners. Next plan is to work around the join with a knife freeing the head and lifting it free.

Ha ha ok! I was afraid to whack it too hard for fear of shearing the little bastards and/or moving the liners. Next plan is to work around the join with a knife freeing the head and lifting it free.

NO !!!!!!!!!!
If you damage the block you're well fecked .It'll come off with a bit of patience .There is a lot of shite around the bottom liners holding them down ...............usually

I would say 'Im glad Im not the person here recommending people don't use gaskets...'

Go and order a timing cover gasket from Renault and see what -they- tell you.

All the gaskets are available and much cheaper from Volvo, FWIW.

What will they tell me...'Don't use a gasket, use silicone sealant? - '

I hope so because that will make them liable and give me a new engine when I dump 3 tubes of the stuff inside the timing cover on purpose

They will tell you "there's no gasket listed for the Z7X engine, they were assembled with silicone from the factory." And no, they can't be held liable for you being dumb. In fact they can't even be held liable for the work involved with supplying dodgy parts, only replacing said dodgy part.

They will tell you "there's no gasket listed for the Z7X engine, they were assembled with silicone from the factory." And no, they can't be held liable for you being dumb. In fact they can't even be held liable for the work involved with supplying dodgy parts, only replacing said dodgy part.

Thats brilliant. Unfortunately the originator of this thread doesn't have a Z7X so your advising against what Renault advise, agree?

Martin, if you assemble an engine with silicone, and it gets into the oil pump and kills the motor, then you are liable (though your lucky you have public liability insurance ). If you use a gasket, then there is no way in hell scenario can happen.

how much longer can this go on... the gasket is not available from Renault, the Z7X never used timing or rocker cover gaskets, and I've never had any problems using just gunge. I can't see how a small fragment of silicone would damage a chain driven gear pump with hardened teeth. That's assuming it manages to get past the strainer in the sump, assuming further that there was any to get there in the first place, which if using it sparingly as advised should never be a problem.

Okay, ignore what I've said, use a gasket. I'm sure Dave will be happy to supply them.

:roll: how much longer can this go on... the gasket is not available from Renault, the Z7X never used timing or rocher covers, and I've never had any problems using just gunge. I can't see how a small fragment of silicone would damage a chain driven gear pump with hardened teeth. That's assuming it manages to get past the strainer in the sump, assuming further that there was any to get there in the first place, which if using it sparingly as advised should never be a problem.

Okay, ignore what I've said, use a gasket. I'm sure Dave will be happy to supply them.

Because.....drum roll...

If your assembling an engine from scratch, and have it out the car, and lay it on its back, line it up easily, then there is probably no issue with using a decent sealer...and it can dry for time etc, then fill the engine with oil etc, run it..

But seeing as most people are going to have the engine in situ, ie vertical, with oil inside most of it, trying to place a timing cover on the engine in the correct position first time while you lay on your back on the floor is a logistical nightmare, abeit managing to lose most of the silicone seal in the first place as it touches parts of the engine you didnt want it too, hence defeating the object of being a 'seal'...

'I can't see how a small fragment of silicone would damage a chain driven gear pump with hardened teeth. That's assuming it manages to get past the strainer in the sump, assuming further that there was any to get there in the first place'

...and that in there lies the problem... It can, it does.

... the gasket is not available from Renault, the Z7X never used timing or rocker cover gaskets, .

And why do you keep going on about Z7Xs! He hasnt got a Z7X, and the last time I looked my two A610s had timing cover gaskets...

I've found gaskets to be about ~50% reliable after first fitting them. So far I've had 100% success with gunge, including in-situe, if cleaned properly first.

Another problem with the gaskets is the ease with which any one of the three covers can be cracked when installing a new gasket. You have to go around every bolt in a circuit about 5 times to get them tight enough to seal without cracking. NB this applies only to the ally covers and the fibre gaskets. The steel covers should use the rubber gaskets.

And why do you keep going on about Z7Xs!

Because it has the same timing cover footprint and is a lot easier to order stuff from Renault if you're ordering from a later car with the reg number, than a GTA or 610 on which they don't hold data.

2x 610's? Why weren't you at Brunters?

And why do you keep going on about Z7Xs!

Because it has the same timing cover footprint and is a lot easier to order stuff from Renault if you're ordering from a later car with the reg number, than a GTA or 610 on which they don't hold data.

2x 610's? Why weren't you at Brunters?

Well if its the same timing cover footprint, then its no different to an early GTA which uses, (as advised by Renault) a gasket then...

Remember the Z7X came out in 1988 and had a timing cover gasket way back then.