Changing the head on a AAZ - tips please

Post by **ringo** » 20 Oct 2008, 16:45

Right - due to overheating, the heater keeps going cold, water coming out of the main expansion tank into the overflow and lots of people telling me that my head gasket has gone, i have taken my head off my spare AAZ and taken it to get skimmed.

At the weekend i am going to take mine off (and i hope the gasket has gone after all this) and put on the freshly skimmed spare one.

Q1) Can i keep the manifolds on while taking the head off and putting it back on?

I've read the wiki page here and done a search and i reckon i need to do this:

Im in situ so im going to use some old bolts like in this photo (bottom one) to make putting the head on easier..

[img:800:600]https://club8090.co.uk/wiki/images/Head- ... sel_01.jpg[/img]

Im also going to modify another bolt like the middle one so i can clean up the threads to make sure the new stretch bolts go in unhindered.

Then, im going to put on the new gasket the same way as the old one came off. Got a 3 notch as recommended for a skimmed head.

Q2) Do i use any sealant on the gasket? Im guessing not.

Im then going to put the head on and put in the new bolts (and remove the peg bolts).

Im going to tighten the bolts as Mr Simpson states "40nm then 60nm then 1/4 turn then 1/4 turn". Im going to do a triangular order to get the head down flat.

Q3) Whats the exact order to do the bolts up?

If anyone has any further tips or recommendations they would be much appreciated.

Thanks

Ringo

Post by **nindy** » 22 Oct 2008, 08:46

Hi mate,

Dont use the old bolts you can get a kit inc gasket ( german make) cam bolts etc .. from any good engineering compnay who skim heads.

I had mine done I took it apart but got a prof to do it as peace of mind I didnt skimp on anything really tried to used new bolts and bits as its only going on the once and you might as well do it properly.

Post by **nindy** » 22 Oct 2008, 08:47

NO gasket sealant required for this mate, however as the the time i had my gasket changes I had my bottom pulley changed as well and I asked them to use locktite !

Post by **ringo** » 22 Oct 2008, 12:20

Thanks - im going to use new stretch bolts.

Anyone know the exact order to tighten the bolts ?

Outside in/opposite?

Thanks

Ringo

Post by **HarryMann** » 22 Oct 2008, 12:52

It'll be on sheet in or actually printed on the head-gasket packaging...

If not then ask again..

Post by **ringo** » 22 Oct 2008, 15:21

Ahhh - thats useful!

Thanks Clive

Ringo

Post by **nindy** » 22 Oct 2008, 16:00

Im sure Mr baxter can tell you if I was you I would ask the guy who is skimming the head they are normally prett good, the guy who skimmed mine asked me I wanted the gasket kit after I had it skimmed.

Post by **HarryMann** » 22 Oct 2008, 18:34

These heads are not normally skimmed... how much do you think wil be taken off?

Post by **jamesc76** » 22 Oct 2008, 19:11

Do bolts up middle out in a circle, do you need any torque wrenches and angle guague??

Post by **mrhutch** » 23 Oct 2008, 00:30

good luck marra...

When I've done mine it's all been pretty plain sailing. I hope it is the head gasket and then you're sorted.

Hutch

Post by **ringo** » 23 Oct 2008, 08:09

HarryMann wrote:These heads are not normally skimmed... how much do you think wil be taken off?

Mixed information here. Im hoping i got as little skimmed off as possible to make it flat.

jamesc76 wrote:Do bolts up middle out in a circle, do you need any torque wrenches and angle guague??

Thanks James - all sorted for torque wrench - im assuming i need a angle gauge to do the 90 degree turns?

Ringo

Post by **HarryMann** » 23 Oct 2008, 08:51

No, either eyeball it or put a dab of tippex white on each polyhead after 2nd torqueing and note where it's got to tend up each time, use a powerbar.

It'll frighten you though if it's the first time!

A lot of mechanics soak the bolt threads in engine oil first then drain them well (a good while!) before fitting. Pretty sure that's even in the VW manuals but not in Bentley.

I've never done the 3rd 90 after starting up and getting up to temperature, nor the post 1,000 mile 90 degrees... so did 40; 60 N-m + 90 + 90, as AndyS method in Wiki.

Twice!

Neither time have I had problems, first engine did 10,000, no head problems, this time I'm at about 5~6,000 miles without problems and the pressures are certainly high in the engine.

I am not 100% sure what the current VW recommendations are as they do issue changed recommendations as time goes on... e.g. the modified timing sprocket.

Post by **ringo** » 23 Oct 2008, 09:33

Thanks Clive,

Im hoping i can pop the head off with the manifolds on - just to make swapping them over easy.

I cant think of any problems doing this - will line up to TDC first of course.

So if i take the head off and its not cracked - will it be fine to re-use it with just a new gasket? (a 2 notch).

Cheers

Ringo

Post by **HarryMann** » 23 Oct 2008, 17:18

Shouldn't be a problem, but I think I found a wee hassle, with the exhaust manifold slightly overlapping the head face and compromising the head then sitting down nicely, which I put down to the AAZ engine and JX manifolds - maybe just look carefully first. Of course it shouldn't be a problem, but think I then preferred to put manifolds on afterwards, as had torque down problems the first time anyway (bad threads in block)... I might even have relieved one or two areas to make sure there was no interference, but cannot remember

If you clean the surfaces up well, I put pistons half way down and stuffed the bores with rags, lipped a bit of grease around , and scraped them down. Might then have used a scotchbrite pad.
I used a 3 notch regardless.

Post by **ringo** » 25 Oct 2008, 12:28

Well, got the head back on and now it runs terribly.

Sounds like its running on 3 cylinders - wont idle and lots of white smoke.

There is also a leak at the exhaust manifold (which may have contributed to my overheating issues?).

I dont really know what to now apart from buy new bolts, gaskets and try again.

Bugger.

Ringo