Head gasket, studs, timing, etc.

[speedy]

Well since retorquing is such a big job for me compared to someone with, say a Jetta, I will probably not do it unless (God forbid) I have the engine out for some other purpose.  I may even give ARP a call just to confirm that the lack of retorque instructions was intentional.  Thanks for all of the replies on this.

-David

[speedy]

I called ARP today, talked to "Al".  He said that re-torquing is dependent upon the head gasket, not the bolts or studs.  Since I am using a factory head gasket, he said I needed to follow the factory torque procedures which includes re-torquing.  Not the answer I was looking for, but there it is.  I'm thinking about starting up the engine on the garage floor for the first heat cycle and re-torque, then either taking a chance and skipping the second one, or biting the bullet and doing the 6-hour engine R&R for the second re-torque.  Of course, none of that may be necessary now, details in the next post.   

-David

[speedy]

I finally got comfortable enough with cam/injection pump timing to remove the cam pulley and take the head off the block. 

The good news is that I found some evidence of a water breach.  The head bolt between cylinder 3 and 4 on the back of the engine (intake and exhaust side) came out all rusty and there is some corrosion around the water port next to it leading to cylinder #3.  It's not a slam dunk, but since the water obviously made it through the gasket to the head bolt, it is pretty likely that it also made it through the gasket to the combustion chamber, or rather the reverse happened (combustion chamber gasses made it into the water passage).  Here is a link to a shot of that area (warning: large image):

http://motorheads.net/vw/gtd_forum/water_leak.jpg

The bad news is twofold.  First, there are cracks between the valves on all four cylinders.  I was prepared to see that but I am a little uncomfortable with the size of the cracks and how much they have opened up.  Here is a low-res picture of one of the worse cracks:



Links to high-res pictures of all four cylinders:

http://motorheads.net/vw/gtd_forum/crack_cyl_1_closeup.jpg
http://motorheads.net/vw/gtd_forum/crack_cyl_2_closeup.jpg
http://motorheads.net/vw/gtd_forum/crack_cyl_3_closeup.jpg
http://motorheads.net/vw/gtd_forum/crack_cyl_4_closeup.jpg

Then more bad news - when I wiped off the tops of the pistons, I found some pitting in cylinder #4.  Note that it is not visible in the water leak picture above due to being covered with a very light layer of carbon:



Link to high-res image of pitting:

http://motorheads.net/vw/gtd_forum/pitting.jpg

Am I screwed?  This engine ran pretty well when I took it apart except for the pressure in the coolant system.  Can I just bolt it back together and expect it to survive?  Or should I just start over with a new engine?

Thanks,

-David

[Vincent Waldon]

Based on that picture those are very reasonable cracks between valves... very reasonable. You'll want to carefully clean the head and look for cracks in other places, but if that's the worst you've got yer fine.

In terms of the piston erosion I'd say you need to pull the piston and if the erosion has impacted the area around the top ring at all.  If the picture is pretty much shows it all again you're probably also good to go... unless you're a serious perfectionist.  

And of course that errosion tells you you really really really need new nozzles.

[speedy]

Thanks Vincent, I feel better now.  I read your writeup on rebuilding IDI injectors, very nice.  I think I will disassemble and inspect the #4 injector tomorrow and see if I can find the cause of the problem.

-David

[burn_your_money]

The double crack on #2 is a bit worrying to me.

Visually you can look around the needle on the injector. If it's deeply eroded you can guess that's probably no longer spraying very well. You can do that without taking them apart. Like Libbybapa said, without a pop tester you can't see much else.

[CdnVWJunkie]

I just stumbled across this post.  Great project BTW. 

I have an idea that you may or may not have already considered adding a T3 Vanagon style upper engine lid.  That would make a world of difference in adding lots of engine accessibility for re-torquing your head studs.  A bit of work, yes but so is pulling your engine 2 or 3 times to re-torque.

How did you go about the radiator?  How about IC placement and plumbing?  Did you go with a KEP adapter or OEM brazilian bellhousing?  At some point I'd like to do this swap to my '74 Westy but for now the 2.0L is healthy enough that replacement would be "creating" work I don't have time for.   Sorry to go off topic somewhat.

[saurkraut]

I called ARP today, talked to "Al".  He said that re-torquing is dependent upon the head gasket, not the bolts or studs.  Since I am using a factory head gasket, he said I needed to follow the factory torque procedures which includes re-torquing.  Not the answer I was looking for, but there it is.  I'm thinking about starting up the engine on the garage floor for the first heat cycle and re-torque, then either taking a chance and skipping the second one, or biting the bullet and doing the 6-hour engine R&R for the second re-torque.  Of course, none of that may be necessary now, details in the next post.   

-David

I did ARP studs and fiber gaskets in both my 1.6/1.9 franken motor and the 1.5TD.  Re-torq is necessary.  Quite a few studs took more twist in both engines.  No leaks!

[speedy]

I have an idea that you may or may not have already considered adding a T3 Vanagon style upper engine lid.  That would make a world of difference in adding lots of engine accessibility for re-torquing your head studs.  A bit of work, yes but so is pulling your engine 2 or 3 times to re-torque.

I have considered that, and someday may do it when my welding skills have improved to the point where I won't make a total mess of it.  So far though, I haven't found the smaller hatch to be much of a problem.  This is the first time I have wished for more room.

How did you go about the radiator?  How about IC placement and plumbing?  Did you go with a KEP adapter or OEM brazilian bellhousing?  At some point I'd like to do this swap to my '74 Westy but for now the 2.0L is healthy enough that replacement would be "creating" work I don't have time for.   Sorry to go off topic somewhat.

I have dual radiators under the floor.  Intercooler is a Saab unit going in the left side battery box, using 2" exhaust tubing and silicone couplers (not finished yet).  KEP adapter.  All of the details are on my web page:
http://motorheads.net/vw/turbobus
I understand your reluctance to take out a perfectly good engine - I would not have done that to mine either, but fortunately (?) my engine was on its last legs.

-David

[speedy]

Thanks for all of the replies on the head cracks and piston erosion.  I have decided to put the engine back together and run it - if/when it dies, I will consider it an "opportunity to upgrade" and swap it for a 1.9L.

I called a couple of diesel shops here in the Dallas area today, but none of them would work on less than an 18-wheel truck engine.  Any chance I can get away with just buying a rebuilt Bosch injector to replace the one that was in #4?  Or can someone recommend a place in the Dallas area that can do the pop test for a reasonable price or sell me a good used injector?

Finally, I checked my valve lash and #1 intake is .005".  I don't have the tool or any shims to adjust it with.  Okay to leave it at .005 or should I bite the bullet and buy the tool/shims?  The rest of the valves are all within spec (8-12 intake, 16-20 exhaust).

Thanks,

-David

[burn_your_money]

I have a shim kit and if you cover shipping and send me your old shim I`ll send you the proper size.

[VW Smokr]

Have to agree on the threatening appearance of that 'double-crack' in #2 combustion face.

I'd at least drop the $30. or so it costs to have a machine shop pressure-test the cylinder head. If it does have a leak, it's just wasted time & money to put it back in 'as is', especially with all the good efforts you've put into the project already.

Some have said there are actually talented welders/machine shops who can successfully weld up these almost-universal cracks... IDK. If true, I'd like to know where they're hiding.

Good luck with it.

J.R.
SoCal
 

[speedy]

I found a local shop to pop test the injectors.  Able Fuel Injection Service (http://diesel-fuel-injection.com/).  They told me that the #4 injector was fine, so the damage to the piston must have come from something else (being that the history of the engine is unknown, it could have been just about anything).  They did say that the #1 and #3 injectors were leaking and that all were very worn and recommended I let them rebuild all four injectors at $55 each.  Normally this kind of response raises the hair on the back of my neck, but I got good vibes from this place so I told them to go ahead.  They said they use only Bosch parts.  When I got home and looked into the holes where the injectors had been, I saw a lot of soot and carbon in the #1 and #3 holes and none in #2 and #4, which is in line with what they told me.  I get the injectors back tomorrow.

I also removed the camshaft to adjust some of the shims.  I do not have a Bentley manual (I am too cheap to pay $100 for a manual that covers all gas/diesel Quantums when I don't even have a Quantum any more, only have the diesel engine in a different vehicle) so I hope someone would be kind enough to tell me how to retorque the cam once I am done.  Couldn't seem to find it with the search.

Thanks,
    -David

[Mark(The Miser)UK]

VW service manual says to set cam to #1 TDC, and install caps #2 and #4 first. Torque down alternately/diagonally. Final value is 20NM. It doesn't say, but I'd do it in 2 stages.
#1 cap, is next to pulley. Then do #1, 3, and 5 [I assume zig zag, although it doesn't specify]

[Turftech]

Just my two bits but...

I had similar cracks with my MF and even had slightly worse damage on my #1 piston.  I worried the issue for days, then decided to roll with it.  65'000 kms later and no problems at all.  Unless you are gong for mint, there is no harm in going with what you see.  As others have said, there can be much, much worse.  These engines are damned near bullet proof.  Being as it is going into a doghouse, I would have the pump reconditioned as well as the injectors.  And change every hose and belt you can see!  That should buy you a couple years.

Should be a solid bus when you are done.