1.6 n/a injector seat cracks? Help!

[hibbcase]

Hi I'm new to the vw world but not to diesels. I have been tinkering with my 1986 golf and have had some leaking around the injectors and pulled them out to find that the seats in the head where the heat shields sit are cracked/burnt out. All four are like this but one is worse than the others.

This first one is the worst and leaks the worst. Is the purpose of the heat shields mostly to protect the injectors or is it to protect burnout like I'm seeing. The reason I ask is because the worst hole (the first pic) actually had two heat shields installed with the injector, which I'm sure messes with spray pattern and combustion. The lower heat shield was pretty stuck down in there and it took some negotiation to get it out. would this have caused what I'm seeing? Again any input and help is appreciated.

[theman53]

I would guess with the thickness of 2 heat shields the spray pattern ate the head away. I don't like the looks of it, but if you have a friend that is excellent with a tig welder it might be fixable. If the rest of the head is not in the greatest shape I would recommend finding another one. It will cost a lot to get this into shape that finding a replacement will be cheaper I am sure.

[745 turbogreasel]

Is the purpose of the heat shields mostly to protect the injectors or is it to protect burnout like I'm seeing. The reason I ask is because the worst hole (the first pic) actually had two heat shields installed with the injector, which I'm sure messes with spray pattern and combustion. The lower heat shield was pretty stuck down in there and it took some negotiation to get it out......
........ would this have caused what I'm seeing?

Dual purpose, one is  the seal washer is  to seal in the combustion pressure. Two it isolates the injector somewhat form  heat....
...Yes it would

I do not think its  caused by spray pattern so much as  the  double seal being the wrong shape to crush the washer in position,  resulting in a small compression leak.  Exhaust gas is under very high pressure, and corrosive so it  cuts a big hole in short order.

My guess would be  somebody reused  the crush washers without  rebending them, or  left the injectors a little loose.

[theman53]

I was just thinking the spray pattern being up another 1/8" above where it should be running 2 thick might cause it to hit the head.

[ORCoaster]

Hibbcase,  Welcome to the fits of the VW!   I was wondering what is going on with the glow plugs on this head.  Perhaps it is the pictures but it almost looks like you are missing the top portion of the GP fitting.  Is that the case?

I agree with the fix is going to cost more than the replacement here.  Getting the head off and to someone that can TIG weld it up and remachine it isn't going to be easy.  I had a cracked injector boss on a head of mine once and the guy that came over to check it out said yes doable, repair questionable.  I replaced the head and scrapped the old one. 

I don't see any good way of making due here.  Someone's idea for two heatsheilds is better than one was not the solution.  Like it was mentioned they have to be installed so that they fit tightly to the head and the base of the injector.  That is accomplished by a very small bit of cupping of the heatsheild up towards the center of the sheild.  Once you start tightening on it the injector pushes against the center and then forms a tight seal at the edges as the whole thing deflects. 

That ensures that the heat transfer and spray pattern stay as they are designed to and the result you are seeing doesn't happen.  I almost think someone didn't know how to tighten down the injectors on a VW diesel here and just left them loose. 

Sorry for your find here.  It sucks to see this sort of thing on what is quite possibly a decent head otherwise.

 

[Dakotakid]

Hibb, how is this head performing otherwise? Running good?

So, this was pushing fuel up through the injector threads and bubbling? If so, WERE the injectors tight?

This guy might be a good candidate to purchase one of those bare Chiner Pete heads and swap over the components....yes? However, the valve stems probably have wear. He would have new guides in the Prothe head.

Just out of curiosity, why would the erosions all be located in that same general location?

[TylerDurden]

Might be a victim of dribbling injectors. (Easy to replace glowplugs to hide the evidence.)

There might not be enough material left to resurface.

Here's a profile:

[burn_your_money]

I would say that was caused by the double heatshields, a bad spray pattern of the injector or dribbling injectors. I would lean more towards dribbling. This would create a pool of diesel that would burn during the compression stroke. Since this pool is not atomized it would burn very hot, and would burn through the aluminum. I would definitely get all 4 injectors tested.

Since the head is still installed, I would try new heatsheilds and good injectors and see how you fair. You might be fine.

[Dakotakid]

Well, that was sort of what i was thinking as well.
However, is this bound to ultimately crack the head and drop the precup. Or would his first hint be a matter of getting oil in his anti-freeze?

I was also wondering if someone had installed heat shields and left carbon on the "shelf" and the heat shield never did touch the proper surface in some spots?

However, I DON'T think I would head out for Bolivia or something. I wouldn't go any farther with this car than what I was comfortable walking.
I would sure be searching for a replacement as of yesterday morning!

[burn_your_money]

It's hard to tell from a picture just how bad it is, but it looks like there is a lot of "head" left before it starts effecting the precup. Assuming that the issue is bad injectors or heatshields and you fix that problem, it shouldn't get any worse.

That said, I would keep an eye on the classifieds for a spare head because if (when) the headgasket goes, I wouldn't want to put that head back on.

[hibbcase]

Wow, I posted this on vwvortex diesel section and haven't gotten much more than a peep out of anybody. Thanks for all the input and ideas. I was wondering how thick the injector seats were, that cutaway show's it quite nicely. I was also curious as to what would cause the same corrosion or wear on all four seats.
   When I pulled out the other, non doubled heat shields, they had no contour or curve in the center where it looks like it's supposed to seal against the injector. Meaning they were not properly, re-bent. I really don't see any way I'm going to get a good seal especially on that first hole.

Hibbcase,  Welcome to the fits of the VW!   I was wondering what is going on with the glow plugs on this head.  Perhaps it is the pictures but it almost looks like you are missing the top portion of the GP fitting.  Is that the case?

I'm not sure what your seeing. As far as I know they are intact and functional.

Hibb, how is this head performing otherwise? Running good?

It seems a little smokey on start up and stumbles a little bit until it warms up. Once it's warm it purrs like a kitten. Well a four cylinder dieseling kitten at least.   

Thanks for the input. I may try some new shields and at least get the injectors pop/leakdown tested and see what happens. Anybody know of a good place to find a decent head?

[745 turbogreasel]

There is a cutter tool for cleaning up the injector seats, but I have  cut teeth on a seal washer before for that purpose.  Never tried on a seat that boned though, IMO #1 is not looking promising.  Compressed air in the glow plug hole while you work would keep chips to a minimum.

Another possibility of how...all the damage is on the low side of the hole where grit is sitting if you put it together without cleaning.

[TylerDurden]

I'd get a borescope and look into the hole. The erosion could also be around the precup.

Might be fine, but can't hurt to look.

[ORCoaster]

Mine eyes mine eyes, what is wrong wit mine eyes?   I have same problem of perspective when I look at aerial photos with a stereo scope.  Sometimes the shadows and such make it look like there is a hole when it is really a ridge.  Like in the first picture, that area where the GP goes into is rounded on top but the shadow cast from up above makes it look like a depression.  So I was thinking that bright area is reall the straight part of the GP down in a hole carved out of the head itself. 

Looking at it again tonight I see the hump and my pea brain computes it to be correct not all messa up.

Sorry I will wear better glasses or wash the ones I wear. 

[tyb525]

I thought I was the only one with a head like that. 3 of my injector seats were like that when I got the car, but not quite as bad. New injectors and heat shields had been put in before I bought it - I attribute it to driving it home an hour with very, very, very retarded timing (it barely ran and smoked like crazy).

I was able to put in new heat shields, one injector has a little carbon buildup around it, but it seems to have "sealed up" or whatever. It has been fine for 25K miles now. I wouldn't have ran the head, but I didn't have any more money to put into the car after re-ringing and replacing the head gasket and bearings. I figured I would replaced the head "later", but it hasn't caused any problems and I haven't gotten around to it yet...