AAZ New head gasket gone after long journey, please help

[HarryMann]

Whilst we are thinking of the torque - are you sure that the torque wrench is good? Just a thought.

.. .NB. My comments above about the thread hole wells and correctly lubing the bolts

Torques vary greatly when compressing incompressible liquids in blind holes, dry Vs boundary lubed friction plus and definitely you must be very careful with torque wrenches (particularly cheap ones) if you don't use and cross-check them regularly.. that is, good mechanics are typically very pessimistic and untrusting types

Measure twice, cut once and all that...

[airhead]

Wow loads of info here now. I don't have the gasket any more. I dropped it in with the head to show the lads who were inspecting that. They showed me where it delaminated between cylinders 1 and 2 and into the water passages. It was definitely gone. As far as torquing was concerned, I did use Newton Metres. I got confused between the 2 cause we always use imperial measurements in work. I went with what it said in the manual anyway. I wouldn't have thought the el cheapo torque wrench I have is too accurate. It's one of Lidl's finest. I'll borrow a properly calibrated one from work this time though. So should the bolts be installed dry or lubricated? When I took the old ones out the first time I did the gasket they had copper grease on them, but that gasket was gone too so I'm not too sold on doing that again. I'm looking at the manual now. I notice it says in big bold letters "Diesel engine cylinder heads cannot be resurfaced!"

Does anyone have a link to an AAZ manual? I think the lad who told me that installing the AAZ head was the same as installing the JX head may have been talking through his back passage, and hence I went wrong on a few procedures. Looking at the JX manual (which is what I used) I realised I torqued 40NM, 60NM, 75NM, 180 degrees, then a further 90 degrees when the engine was hot. Clearly wrong based on what you lads were saying, then there was liquid and/or dirt in the bolt holes and I didn't lube the bolts. Hmmmm....

[Oldiebut goodie]

The Haynes VW Golf and Vento '92 to '98 covers the 1Y, AEY, AAZ, 1Z, AHU, ALE, AFN, AVG engines.

[HarryMann]

No, def not CopperSlip

As I said, soaked in engine oil overnight and then well-drained is VW spec

[max and caddy]

Although I agree and do the same myself I have had a few sets of head bolts from my local engine man (Lancaster engines) of a non genuine kinda type...Brazilian I think...and they actually come with a sachet of coppergrease! I binned it but its shows a pictogram of it being applied under the bolt head...not on the threads tho...either way I use gear oil on mine and no failures yet!

[airhead]

Just after reading said manual there. I got a copy of it. I now realise I made a complete and utter f*ck of this job! Thanks a lot for all the info lads. I overtorqued the bolts by 90 degrees for a start, and installed the bolts dry with dirt in the holes. That and the timing belt wasn't correctly tensioned.

[HarryMann]

Fairplay then..

There's quite a few of us on our second engine or 2nd rebuild with these 'ticking timebombs' as a certain person calls AAZs

Fortunately, I had a very good tutor (thanks AndyS, long time no see), and did pretty well most things right, and didn't have head problems after the original virtually melted away

One thing to always be aware of though, is if the turbo starts wearing it's bearings & seals and passing a lot of oil (and that doesn't affect boost, or anything else performance wise), then this:

a) lowers overall engine oil pressure;
b) raises the engine oil temperature;
c) reduces the flow of oil through the engine proper.

none of which are conducive to a long engine life.

The low turbo 52 degree JX installations, are notorious for hot turbos, poor flow through the turbo and cornering affecting the oilflow... everything has to be right, for the installation as designed, to work OK. That's my take on it anyway.
The high turbo AAZ installations are better done properly, in my opinion. An upright engine in a pickup, perhaps even better?

PS. I also always use the baffle plate sump gasket (integral windage tray), some do, some don't, usually both swearing they're right

[torchy]

I've read this with interest because I've got a similar problem.

Had an AAZ fitted recently, all going well untill (although a smidge hotter on the temp gauge) it suddenly lost power on the dual carrigeway, pulled in quick and water was pouring (squirting and bubbling) out of the three little holes on top of the expansion tank. This engine has done 160K in a Golf so I'm assuming it chose now to fail, although the garage that did it exchanged the AAZ fuel pump for the original JX Pump and had to cut a section out of the cambelt cover for it to fit!! Grrrrrrrrr, still not sure why?
RAC reckon the the head gasket has gone.
Assuming it has can anyone recommend a good company to get the head overhauled and skimmed (if necessary).

......and where can I buy an injector socket to remove the injectors so I can do a pressure test first, I got one from Baxter but it doesnt fit....they have had a supplier problem it appears and no worries they are taking it back.... but I still need a 27mm deep socket to get the injectors out.

Comments welcome............Many Thanks

[HarryMann]

In theory, you're not supposed to skim those IDI diesel heads. Might be best to check what is really going on first, whether gasket leaking (hard to be sure sometimes), or cracks in head.

New waterpump? Fan belt A-OK, not slippy screamy?
Tend to think if left in Golf 160,000 would not have been its demise...
Oil cooler?
Think I just ground down a normal 27mm deep socket, but many places sekll them (eBay?)

Good luck, let us know the pressures.

[ELVIS]

Silly Q time...........

Why are bolts soaked overnight and not just dunked/coated while you are doing the job?

[HarryMann]

Because I was told that by a man that knew, and presumed it came from VW works manual or the gospel according to St. Andy...

If so, I imagine that five minutes a bolt with oil NOT wetteth*

* to wet being to diminish all said surface tension and enshure said mohecules adhere to said metahl

Best Regards

Hope to see you in Devon again around August time

[ELVIS]

Cheers chap. That's tonight's google mission sorted then, off to read all I can

As an aside remember being as young as 12 and polishing the bottom of our race boats to reduce wetted surface area, didn't know what it meant then but Olympic champions did it so we did

[billy739]

I've never seen one that could keep all three fluids in the right place; high compression + cast block + alloy head + turbo

yes you have!

24000 miles in 2 years , 34mpg 60-70mph cruise on a 82000 mile scraper motor!

without all going through posts, whats your driving like , what gearbox and tyre combo do you have? what would you say your cruise speed is, how loaded is your van generally?

[torchy]

In theory, you're not supposed to skim those IDI diesel heads. Might be best to check what is really going on first, whether gasket leaking (hard to be sure sometimes), or cracks in head.

New waterpump? Fan belt A-OK, not slippy screamy?
Tend to think if left in Golf 160,000 would not have been its demise...
Oil cooler?
Think I just ground down a normal 27mm deep socket, but many places sekll them (eBay?)

Good luck, let us know the pressures.

Yes it was a new water pump and the garage fitted the JX fuel pump (still not convinced why they did).

I finally got a 27mm "snap-on" deep socket to fit after grinding down the outside and getting a second mortgage to pay for it. Fabulous kit though, has to be said, up there with BAHCO!

I've forgotten the cylinder configaration (where is number 1?, been fiddling with the WBX too much I think), Pressures as follows Number 1 closest to flywheel:

No 1 26.5 Bar 390psi
No 2 28.0 Bar 410 psi
No 3 25.0 Bar 360 psi
No 4 Zero, I could actually put my thumb across the injector hole and hold it there while turning .

Anyone know what they are supposed to be? I can't find the info anywhere, nor the cyl configaration, maybe I'm looking in the wrong place?

Looking inside the injector hole the injector seat has erroded/corroded and there is a hole in way of the glow plug. Looks like that's the culprit.

I'll post some pics if anyone is interrested, Under a new post to be fair, apologies for hijacking this one.

I think this head is dead, I'll take it off and confirm but in the mean time I still have the JX which was supposed to be an overhauled engine but it lost it's lub oil pressure and the big end went, hence fitting the AAZ, Does anyone know if I can fit the JX head to this AAZ? At least that will get me up and running again fairly soon. Although If it will fit I'm slightly concerned that the low oil pressure might have effected the camshaft bearings? Any thoughts?

I would check ETKA but it's still not working .

Think I might be slipping that 1.6 non-turbo back in again Clive, think I'll put wing nuts on it

Only tool I'm missing is the star socket for the turbo bolts, what size do I need???

Many Thanks for any feedback

[HarryMann]

I think its about 12mm bi-hex fits those (v.expensive) turbo bolts, so don't need a star one, they're just funny shaped normal hex bolts

Think 400 psi + is what you're looking at pressure wise, cyls are numbered 1 > 4 from the pulley (water pump) end.

It has probably cracked between the valves or across the pre-chamber