Author Topic: can I machine the injector seats in the cylinder head?  (Read 5088 times)

September 07, 2005, 05:54:08 am

chrissev

  • Veteran

  • Offline
  • ***

  • 694
can I machine the injector seats in the cylinder head?
« on: September 07, 2005, 05:54:08 am »
Injector seats (where the heat shield contacts the cylinder head) are pitted and heat shields are leaking diesel and carboning up the threads.  Pitting appears to be fairly shallow, maybe 2mm deep in the worst areas.  I'm wondering whether if I take the head off and take it to a machine shop and instruct them to machine the injector seats smooth again, will this solve the problem?  If so, anyone know how much they can take off?  It is really hard to find a rebuildable 1.6TD head right now so I think my best option is to try to save the one I have.  

thanks for any advice

Chris
88 Jetta TD....sold for $1000, bought an 06 Cobalt, clearing out the diesel jetta stuff now

Reply #1September 07, 2005, 07:29:34 am

Maarten

  • Veteran

  • Offline
  • ***

  • 339
can I machine the injector seats in the cylinder head?
« Reply #1 on: September 07, 2005, 07:29:34 am »
The seats cost €2,- at the dealer if I recall correctly...

Machining them off will change the spray in the chamber.. I don't think thats ok  :!:
Audi A3 TDI '98
VW cabby '79
VW T3 1.9TD '91

Reply #2September 08, 2005, 09:52:26 am

chrissev

  • Veteran

  • Offline
  • ***

  • 694
can I machine the injector seats in the cylinder head?
« Reply #2 on: September 08, 2005, 09:52:26 am »
Quote from: "Maarten"
The seats cost €2,- at the dealer if I recall correctly...

Machining them off will change the spray in the chamber.. I don't think thats ok  :!:


are you saying I can remove the injector seats from the head?  How do I do that?  They don't look like inserts.  Are they pressed in?  I thought they were part of the head and not detachable.
88 Jetta TD....sold for $1000, bought an 06 Cobalt, clearing out the diesel jetta stuff now

Reply #3September 08, 2005, 10:09:07 am

fspGTD

  • Veteran

  • Offline
  • ***

  • 1529
    • http://home.comcast.net/~vwgtd
can I machine the injector seats in the cylinder head?
« Reply #3 on: September 08, 2005, 10:09:07 am »
The factory somehow machines those seats on the head assembly line, so there must be some way of machinig it a little deeper.  But, I would be concerned with the thickness of the metal behind the seat.  I would guess it would only be a few mm deep.  You could probably get by machining a fraction of a mm, but 2mm seems like an awful lot to have to machine off, and seems like would run high risk of the seat being structurally weakened too much.  Then it could deform or break when you torqued your injector up.

You might be stuck with having to add material to restore the seat, which could be done either by welding (requires the head be completely disassembled and pre-heated and welded with heliarc, usually done in conjunction with a total head rebuild) or something hodge-podge like filling in with marine-tex or JB weld.  Someone else asked about this before (don't forget to use the search!)

http://www.vwdiesel.net/phpBB/viewtopic.php?t=1537 (Hey this is your thread - a dupliate!  :oops: )

http://www.vwdiesel.net/phpBB/viewtopic.php?t=1410 (Someone else asked same question... you might IM him if he ever managed a fix?)

Another option is a brand new head.  They are available for around $500-$600(ish) US.  Or find a 1.6lNA head core and have it rebuilt with TD intake valves.
Jake Russell
'81 VW Rabbit GTD Autocrosser 1.6lTD, SCCA FSP Class
Dieselicious Turbocharger Upgrade/Rebuild Kits

Reply #4September 09, 2005, 07:40:48 am

chrissev

  • Veteran

  • Offline
  • ***

  • 694
can I machine the injector seats in the cylinder head?
« Reply #4 on: September 09, 2005, 07:40:48 am »
Quote from: "fspGTD"
The factory somehow machines those seats on the head assembly line, so there must be some way of machinig it a little deeper.  But, I would be concerned with the thickness of the metal behind the seat.  I would guess it would only be a few mm deep.  You could probably get by machining a fraction of a mm, but 2mm seems like an awful lot to have to machine off, and seems like would run high risk of the seat being structurally weakened too much.  Then it could deform or break when you torqued your injector up.

You might be stuck with having to add material to restore the seat, which could be done either by welding (requires the head be completely disassembled and pre-heated and welded with heliarc, usually done in conjunction with a total head rebuild) or something hodge-podge like filling in with marine-tex or JB weld.  Someone else asked about this before (don't forget to use the search!)

http://www.vwdiesel.net/phpBB/viewtopic.php?t=1537 (Hey this is your thread - a dupliate!  :oops: )

http://www.vwdiesel.net/phpBB/viewtopic.php?t=1410 (Someone else asked same question... you might IM him if he ever managed a fix?)

Another option is a brand new head.  They are available for around $500-$600(ish) US.  Or find a 1.6lNA head core and have it rebuilt with TD intake valves.


$500 for a new head?  where?  Is there a website?  I might just buy a new head.
88 Jetta TD....sold for $1000, bought an 06 Cobalt, clearing out the diesel jetta stuff now

Reply #5September 09, 2005, 10:04:53 am

fspGTD

  • Veteran

  • Offline
  • ***

  • 1529
    • http://home.comcast.net/~vwgtd
can I machine the injector seats in the cylinder head?
« Reply #5 on: September 09, 2005, 10:04:53 am »
One source is parts place:  (in this link, go to page 10)
http://www.partsplaceinc.com/PDF/PartsPlaceIncCatalog04.pdf

Another source of new cylinder heads is overland parts.  To even get a price quote from them though you'll need to find a dealer, as they don't sell direct.  http://www.overlandparts.com/home.html

I also thought that Topline actually manufactured new (non genuine VW) replacement cylinder heads for our VW Diesels.  However, I was not able to find any listing on their web site.  Might be worth asking them about though, or maybe someone else here can give us the scoop: www.protopline.com
Jake Russell
'81 VW Rabbit GTD Autocrosser 1.6lTD, SCCA FSP Class
Dieselicious Turbocharger Upgrade/Rebuild Kits

Reply #6September 10, 2005, 05:51:50 am

chrissev

  • Veteran

  • Offline
  • ***

  • 694
can I machine the injector seats in the cylinder head?
« Reply #6 on: September 10, 2005, 05:51:50 am »
Quote from: "fspGTD"
One source is parts place:  (in this link, go to page 10)
http://www.partsplaceinc.com/PDF/PartsPlaceIncCatalog04.pdf

Another source of new cylinder heads is overland parts.  To even get a price quote from them though you'll need to find a dealer, as they don't sell direct.  http://www.overlandparts.com/home.html

I also thought that Topline actually manufactured new (non genuine VW) replacement cylinder heads for our VW Diesels.  However, I was not able to find any listing on their web site.  Might be worth asking them about though, or maybe someone else here can give us the scoop: www.protopline.com


Thanks for the partsplace link.  I might just order a new head from them.  The block's already rebuilt so it's probably worth it for the extra $100.  

Chris
88 Jetta TD....sold for $1000, bought an 06 Cobalt, clearing out the diesel jetta stuff now