When replacing the turbo on my AAZ do i need sealant?

[ringo]

I've stripped off the turbo and exhaust manifold from my AAZ to find the horrible noise was due to a leaking manifold (getting skimmed at the moment) and a knackered turbo (for some reason, the exhaust manifold bolts were loose causing the whole thing to rock - this in turn has ruined the joint between the central housing and the cast exhaust housing on the turbo).

Anyway, i have re-indexed the turbo that came off the AAZ.

When fitting the turbo to the manifold, do i need to use a sealant or will clean metal on metal do?

Thanks

Ringo

PS My KKK14 turbo only had 4 bolts holding the ehxaust steel bit on so was very easy to re-index. Only one bolt had to be loosened with a chisel as i couldnt get a ring spanner on it...

[jamesc76]

There should be a gasket (well there is on landrovers /truck ihave worked on!) and we never used any sealant on them, due to the heat in it !

[ringo]

Thanks James,

Nope - VW didnt put a gasket in there. Theres a bit of pitting on the exhaust manifold but hopefully it will be ok....

Ringo

[jamesc76]

Might be able to get some extra high heat gasket sealant??

[caveman]

No gasket. If the surfaces are pitted you can apply a THIN layer of high temp silicone. Can't hurt also to take a large but fine file to clean up the surfaces, but if you aren't sure that you can do right, leave them be. When it's time to bolt everything down, tighten the bolts evenly so nothing gets out of square.

[mattyboi85]

I am in the process of completing my AAZ conversion. With regards the turbo and exhaust manifold seal I read the article in the WIKI pedia and cleaned up both surfaces with fine sandpaper. It took an age to sand through the pitting on both surfaces. Hopefully I will have a reaonably good seal. I read many threads but could not find any that suggested there was a suitable sealant that could be used for this joint.

[Simon Baxter]

You don't want to put anything there.
If you put sealer on it, it could ooze out into the turbo inlet side of the turbine housing, and could break off while your turbo is spinning around at god knows what speed and the debris could damage the turbo.
If the manifold has been faced and the turbo in good shape thats all you have to do.

[ringo]

Thanks guys - i wont use anything and lets hope its ok.

I havent seen the manifold since it was skimmed - but the guy who did it says it was miles out - god knows how it got onto that state.

Im fitting it tomorrow so will see the outcome then...

Ringo

[Snag20]

I flatted mine off using fine wet and dry on a surface plate

[HarryMann]

I havent seen the manifold since it was skimmed - but the guy who did it says it was miles out - god knows how it got onto that state.

Heat and leaking usually, the nuts can come loose. Or the wrong thick washers and nuts have been used.

https://club8090.co.uk/wiki/Te ... ting_faces

A small thin smear of exhaust cement is about the only option, keep it away from the inside joint edge, for Simon's reasons, and don't hang about torqueing the 4 bolts up! But shouldn't be necessary if both faces are good and true.
High temp silicone will not survive cherry red heat AFAIK

Crack-stop drill any bad cracks, about 2mm drill. Can pack the hole with exhaust cement

[ringo]

Balls and balls.

Just put the thing together and the joint leaks.

Will have to try and take it off without removing the manifolds (pain the ass that is) and then use some sealant.

I'd better read the wiki again to find the torque settings ......

E D I T:

Torques - AFAIK, about 33~36 lbf-ft (circa 45 N-m) is the right figure for the four flange-head screws, pulled up in stages.

Its not a hard job - just takes hours!

Ringo

[HarryMann]

Is this a JX manifold or an AAZ layout?

The JX bolts can be got at fairly OK, with a powerbar and short wobbly drive ext. from under the wing (bit fiddly) or easier from directly above in the engine bay with the cannister air-filter out using a longer extension.

About 35 lb-ft, 40 max, in 2 stages. lightly counterbore the seatings in the manifold for the set-screw heads, so they're not pulling down onto badly corroded/uneven faces. The bolts should go to torque from nipped-up in barely half a turn.

Are you sure its not the turbo leaking at the exhaust section seal due to re-indexing. This happened to me on a KKK, not too keen on those weedy little screws c.f. the Garrett - in fact mine had corroded away the radiused seal area so the clamp couldn't get a good grip, and I paid good money for it - the last time I pay more than £50 for a 2nd hand turbo

If you grind down the outside of a quality 10mm ring spanner it should be able to get a purchase on all of the clamping set-screws

[ringo]

thanks Clive,

It's a jx manifold - and I can see bubbles coming out of the joint - so I'm pretty sure it's that.

I will torque it up tomorrow but failing that I will take it off and use some exhaust paste.

The re- indexed turbo works having tested it on a 7 mile run which I'm pleased about.

Ringo