1.9NA head off; things to check or do before re-assembly? - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• 1.9NA head off; things to check or do before re-assembly? by Rock3tman on 21 Apr, 2013 01:14
• My bro's 1Y engine overheated due to cracked thermostat housing...head checked with straightedge and not warped at all (whew!!).   He has ARP 204-4705 studs and new Victor Reinz MLS 3 hole gasket to replace removed parts - -
  
  How do you guys clean & prep the deck and head surfaces for the new headgasket?
  
  install new headgasket with hylomar spray, or copper paint, or dry?
  
  anything else?
  
     
• #1 by wolf_walker on 21 Apr, 2013 09:35
• First, you sell me the intake manifold.
  
  
  Clean and prep deck is a pain, I plug stuff with bits of rag/shop towel and use a shop vac frequently for crud removal.
  An assortment of plastic, wood and metal scrapers and several types of brushes, the goal being a clean surface but no nicks,
  especially the piston tops that are softer.  Bout the same with the head but more so, since it's aluminum.  I've used some gasket removal
  goo sometimes on the deck when it looked like it might help, all depends on how bad it is.
  
  At a shop, one will often take an air die grinder with a scotchbrite disk and just buzz the deck till it's clean, and sometimes
  the head as well.  Lot of folks do a lot of headgaskets that way and get away with it, and it's sure faster.  Your call.
  
  Make sure the 3 hole matches what came off it, I use the copper spray HG stuff myself, lot of folks like Hylomar, lot of em
  swear dry.  I wouldn't do dry unless both surfaces are perfect, and even then I'd ponder it hard. 
• #2 by JamesT on 21 Apr, 2013 09:54
• If you're patient the scotch brite on a die grinder is a good way to go for the block. If you can get away with using it to clean the head and piston tops if you're very careful. Never let the disc edge in, and never let it sit in one spot for more than an instant. If it didn't do first pass, hit it again after several seconds. Heat is the enemy.
• #3 by Gizmoman on 21 Apr, 2013 21:03
• My perspective is patience and about 5 or more spankin new box-cutter blades on the block and the head as well. You hold the blades with your fingers and push it to cut crap off. You can feel when it's right if your patient. Start with the block to get a feel for it. Then move on to the head. The idea is not to remove metal - absolutely none. Sometimes you can hold the blade at a right angle to the surface and scrape but I'd only do this on the block, not the head.
  Personally, I wouldn't use anything powered period. What's the hurry, how many hours would you have to work to earn what a new one would cost?
  
  Cheers
• #4 by monomer on 22 Apr, 2013 18:35
• Quote from: wolf_walker on 21 Apr, 2013 09:35

  
  
  At a shop, one will often take an air die grinder with a scotchbrite disk and just buzz the deck till it's clean, and sometimes
  the head as well.  Lot of folks do a lot of headgaskets that way and get away with it, and it's sure faster.  Your call.
  
  Make sure the 3 hole matches what came off it, I use the copper spray HG stuff myself, lot of folks like Hylomar, lot of em
  swear dry.  I wouldn't do dry unless both surfaces are perfect, and even then I'd ponder it hard. 
  

  
  
  You want the finest cookies you can get. MLS likes a smooth, even finish. I don't know if I would go this route. Razers or a carbide scraper are what I use. Very carefully, at that.
  
  Hylomar is good stuff, well worth going out of the way for. I've heard of some people going as far as pulling the gasket apart and spraying each layer. Dunno if I'd go that far.
• #5 by Rock3tman on 22 Apr, 2013 20:52
• thanks all for the suggestions...I started today with the block & have it to the point where I cant feel anything w/ bare fingers, but there is
  still some color variation (staining?) on the deck.   Good enough?  Found ONE can of hylomar spray in all of Seattle @ Grainger - $34.00
  
  I think I'm going to start tomorrow with lacquer thinner on the head to remove carbon & see just what I've got re: cracks between valves and
  how the prechambers look.  Abrasives are sooo tempting tho for all of this work
• #6 by Rock3tman on 28 Aug, 2013 07:22
• Final results for my first headgasket job:  after 1200 miles, the 1.9NA "runs like a <Libbydiesel> top".   No pressure in overflow tank, oil looks uncontaminated, starts easily, and has good power.  Minor weeping from oil pan gasket, tho...
  
  Torqued ARP studs to 45-90-125 lbs and used hylomar spray after scraping with plastic scraper, brake cleaner, etc.
• #7 by Gizmoman on 29 Aug, 2013 05:08
• Congrats Mr. Glad it worked out for you.
  Did you ever have use abrasives to clean the surfaces or was it elbow grease and patience?
• #8 by Rock3tman on 29 Aug, 2013 07:02
• No abrasives. The engine had less than 7500 miles since a factory reman, but had the overheat episode due to a mechanic over tightening the plastic thermostat elbow and cracking it...so I thought for longevity to avoid the abrasive methods. There was some vw applied goo between block, head gasket, and head tho.