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Just a thought... Could liquid or dirt in the head bolt holes have caused the bolts to not tighten fully and hence cause the head gasket to blow? I didn't clean out the bolt holes when I put the head back on. An oversight on my part.
Yes, think I put that in the Wiki years ago, or mention it in several posts , sop them out with ear buds or the like, or pick about and blow them out; it can be quite important and pre-soak the bolts over night in engine oil, then drain for a good while.
Maybe you've just been a bit unlucky, I wouldn't do the subsequent re-tightening either, 3 years and no problems
You are not alone, this is by far from uncommon though, so as Max says, scrupulous cleanliness on faces or as much as possible. It is normally down at No. 3 or 4 end (front as mounted) that they let go.
I notice that you are choosing a three notch head gasket - is this based on the piston projection? Just that there has been no mention of this having been checked.
It will overheat if you have the wrong water pump on - the only sure way to tell is to take it off and look at the impeller and compare it to the rotation direction of the pulley. I haven't found a list of pumps with numbers and direction of rotation yet and I have been looking on and off for some time.
Oldiebut goodie wrote:I notice that you are choosing a three notch head gasket - is this based on the piston projection? Just that there has been no mention of this having been checked.
It will overheat if you have the wrong water pump on - the only sure way to tell is to take it off and look at the impeller and compare it to the rotation direction of the pulley. I haven't found a list of pumps with numbers and direction of rotation yet and I have been looking on and off for some time.
Regarding the piston projection get the correct gasket my own experiance a three hole will effect performance if incorrect.
A 3 hole gasket is a safe but wrong option....however it will,lower the compression a tiny bit and loses the squish area effect but won't actually cause engine damage.
After all this I'm still not even sure where the gasket has blown! Looks like 2 possible places on the pics.
Big question is how long has the engine been in and running? And if the water pump is spinning the wrong way they overheat more or less straight away all the time...at least t4s do, at idle in fact...so has the engine just gone In or has it been chugging around for a bit and behaving itself?
It went between cylinders 1 and 2. Its not obvious looking at the pics really. That black mark on the head beside cylinder 1 is a black fingerprint from me touching it. The 3 notch gasket was recommended to me by the lad who skimmed the head for me. I didn't measure the piston projection, no. Since I'm replacing the head with a recon one, I'm playing it safe and if that means losing a bit of performance I'm happy enough to to that if it keeps the engine safe. So what gasket is the right one to use on an unskimmed head then?
So hang on now, I'm now confused on the torquing of the head bolts. I did 40 foot pounds, then 60, then turned them 180 degrees when the engine was cold, and a further 90 with the engine hot, meaning I turned them a total of 270 degrees after the initial torque. Was this right?
Not trying to confuse you about loss of performance,But when i had the head skimmed on a 1Y engine cylinder head it came back with a good quality 3 hole head gasket.I fitted the cylinder head & timed up the engine spot on.I did notice a loss of performance it was supplied simply for safety .Regarding the piston projection measure it at TDC above the block then you can select the correct gasket. There is information which gives projection data against gasket thickness for head gaskets ebay is a good scource on supplier listing pages.
I don't understand why people are having their cylinder heads skimmed all the time contrary to VW statements, surely they can't all have warped heads? If you have a warped head the best option is to replace it not to skim it. As it has just been proven by Camper that no measurement is taking place and people are just using the thickest possible gasket provided by the skimmers so that the valves have less chance of hitting the pistons - that is a cop out of doing it correctly. I wonder if you are being informed as to exactly how much is being skimmed and factoring this into the choice of head gasket?
It smacks of doing brain surgery with a spade!
amended for correct projection figures:
0.66 to 0.86mm................1 hole
0.87 to 0.90mm................2 holes
0.91 to 1.02mm................3 holes
Above for 1Y and AAZ.
Last edited by Oldiebut goodie on 04 Nov 2012, 16:39, edited 1 time in total.
Oldiebut goodie in essence i would like to agree with you about not skimming a VW head.But if you talk to engine reconditioners they will say its normal practice to head skim after a pressure test shows okay and removal of the indirect injection inserts prior .The other point i would like to raise is about piston projection and the amount taken off for the skim and its relation to gasket thickness.As once the head is flat after a skim piston projection its relationship to the correct gasket is still the same .I was told this is because there is no combustion chamber in the head thus no reduction for the valves to interfere with pistons. Await with baited breath for your reply. Oh i must say i wouldnt take a dogs chance in this statement as for safety i fitted 3 hole gaskets on the occasions i had a head skim.
It all depends upon whether or not the skim has gone below the lowest point on the head, once the skim touches that the overall head thickness is decreased. With care it shouldn't happen but I sure as hell they don't tell you if they have done so! I agree that the projection is the same - it is the variable of the resultant head thickness that must be taken into account. I am against skimming a warped head as the whole head has then lost it's precision alignment throughout - it is not as though the metal has swollen and you are removing excess that shouldn't be there. As I have said before people get away with it but it isn't the best of practices.
Also it is better to check the piston projection as who knows whether or not it was done when the previous owner had it and put his 3 notch one on.
My local engineer would tell me exactly what was what and I could watch him do it. Funnily enough he bought some of the machines from a machine shop that I used to work in as a teenager and it was nice to see them again!
The last bit of your reply regarding whether or not it was done when the previous owner has its relevents.This very question i raised to a reconditioner who sells a head skim service & reconditioned on ebay.Actually the service and turn around is good for the money.The answer was the head would only be worth scrap but could supply an other reconditioned for the same price .Oh with same 3 hole gasket for safety doh .
The bolts torque was wrong....it's Newton meters not foot pounds! Then 180 degrees. Skimming the heads...well it normally done to remove a bit of damage on the gasket ring area rather than to straighten it out and the valves are in a slight recess..but can protrude, a light cut on the seats normally drops them in to compensate and as stated is not a vw approved procedure.....but needs must at times.
The gasket thickness chart up there is for a JX....I seem to recall it being wrong for an AAZ so double check those values.
You're right - I looked at the wrong book - it was for a 1.6 engine. Can't be *rsed to go down the workshop at the moment, I'll try to remember after some shut-eye.
Whilst we are thinking of the torque - are you sure that the torque wrench is good? Just a thought.
E D I T:
Now amended on previous post.
Last edited by Oldiebut goodie on 04 Nov 2012, 16:40, edited 1 time in total.
Oh i must say i wouldnt take a dogs chance in this statement as for safety i fitted 3 hole gaskets on the occasions i had a head skim.
As I have said before people get away with it but it isn't the best of practices.
