Date: Wed, 7 Jun 2000 03:20:39 -0700
Reply-To: Mark Rokus <marokus@VOYAGER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mark Rokus <marokus@VOYAGER.NET>
Subject: Re: Pitted Heads
Content-Type: multipart/alternative;
I have written my story in the past, but I never took the time to elaborate.
Here is my experience.
An Alternate Method to Costly Head Repair on Leaking Vanagon Heads.
Like many vanagon owners, I was faced with the purchase of a Vanagon that was wonderful except for a little coolant leak near one of the heads. Understand this was "pre-vanagon newsgroup" for me and I had no idea that this was a chronic problem when someone used phosphated coolant.
If your experience is the same as mine, it starts out with an occasional flashing light on the temp gage and a temp needle that is pegged right after starting the van. This is from the level going down in the coolant head tank and not from overheating as the engine hasn't had time to even warm up yet. Its a panic the first time you see it and you check the coolant in the overflow tank. Maybe low, maybe not. The low level sensor is in the tank in the engine compartment (drivers side, to the left of the "add tank") not the one behind the license plate. An interesting thing happens when the coolant is not too low, the light will flash for a few minutes as the system sucks the tank low, and when the engine warms enough to open the thermostat, the circulating action allows the tank level to recover enough for the light to go out. Also, understand that the cooling system fills itself from the overflow tank only when the system is cooling down after you shut off a warm engine. Adding coolant to the expansion tank (behind the license plate) will not immediately fill the system. The contraction caused by cooling fluid sucks coolant from the "add" tank.
One of the difficulties in identifying the leak, is the fact that it may not be leaking while the van is at idle. Quite often, you need to rev the engine while looking into the engine compartment to build enough pressure for the leak to be apparent. You may not even have a puddle as the leak is usually worse when you are under way. Before I realized this, the only way I could tell where it leaked was to notice the funny discoloration on the exhaust pipe where the coolant was squirting when I was driving. After I knew generally where to look, I rev'ed the engine and saw the tiny squirt coming out.
I found that I could buy some time before the rebuild by adding fine saw dust to the head tank. In fact, I delayed the rebuild for almost a year. Now before you blow me off as a hack that dosen't care about maintenence, be it known that I have worked in numerous auto factories and GM puts little cubes of sawdust in every car that goes down the line. I don't recommend it for a long term fix, but it will allow you time to study up and start saving your pennies.
This experience happened on an '84 that already had 100,000 miles on it when I bought it. When I decided that it was time, I dropped the engine and removed the heads. Upon discovering the pitting, I sat and thought about it for a while. I have raced air cooled VW's for a while and I'm not afraid to radically alter the heads, but this was my wife's daily driver.
Option 1) Mill the heads: Due to the construction of the waterboxer, if you mill the coolant sealing surface, you must also equally mill the combustion surface. Great if your looking for performance and willing to run racing fuel, but the increase in compression is not usually desired on a daily driver.
Option 2) Replace the heads: Not even a consideration on my budget.
Option 3) Find a way to restore the sealing surface. I got in touch with the JB Weld technical personnel and they said that their product would withstand 500 degrees. Since the heads are in contact with coolant, they can't get that high without first boiling away all of the coolant. Figured I'd give it a try. Since I didn't have a sandblaster at the time, I carefully cleaned out all of the aluminum oxide (the white, scaly corrosion) with a dental pick. If I did it again, I'd use a sandblaster after masking off the combustion chamber, if only for the time involved. After the scale was removed to my satisfaction , I cleaned the whole surface with a solvent (carb cleaner). I purchased a fresh pack of normal JB Weld (not the quick set) and applied a thin layer to the whole sealing surface and let it harden for a day. After it had hardened, I took a file to the area until I started to get close to aluminum. I had some areas that didn't get filled well so I added more JB Weld to the areas that I had missed. Let it harden another day and got it close again with a file. Once I was close, I got some 400 grit sandpaper and taped it to a flat surface. In my case, a piece of glass worked perfectly as long as you don't drop the head on it. Start working the head over the sandpaper in a figure eight motion and try to keep the sanding even. Look often at your progress and adjust your pressure or motion in able to keep the removal even. Once you start getting down to the original aluminum, you should have a surface that is flat with the pits filled in. If you have any remaining holes, you may have to re-apply and re-sand. I purchased an OEM gasket set and it had the black sealant for the seals and the yellow sealant for the bolts. About $200 for my gaskets.
While I had it down for the repairs, I replaced the bearings, seals, and rings. The crank measured EXACTLY the Bently spec's and I did nothing to it. I did re-lap the valves manually and that was about it. The piston pins can be a bear if you don't have the puller, so be careful to set both pistons to mid stroke to avoid pulling the pistons out of the cyclinders if they stick to the head. I have some ideas if you run into a pin removal problem but that's not the subject of this article. Other than that, pretty straight forward.
The story would end there except that a month later my wife accenditally pulled it into 1st gear while doing about 65 mph. The engine came down again to replace 4 exhaust valves as they all touched when the engine over-rev'd and I had 0 compression. No other damage. Did the work with the engine in the van. Re-used the head seals with sealant that I had left over.
That engine has another 120,000 on it and it has not leaked a drop from the heads. I am no longer afraid of leaking Vanagons. In fact, I look for them as they are good engines when fed and cared for properly. Once you are comfortable with this method, you can find some deals. Basically a total rebuild while repairing the leaks for under $500 and some time.
Hope this helps when deciding which way to go....
Good luck
Mark Rokus
I would imagine that the material that has been posted is due to what has been provided in the past. I think it would be great if you could provide me with an article on the JB Weld method, as I know that it has been popular with many List members. I would be more than happy (and perhaps even grateful) if you could write something up and send it to me.
Thanks again,
Brent Christensen
'89 GL Syncro Westy
Santa Barbara, CA
-----Original Message-----
From: gerry rafferty <gerryr@DIRECT.CA>
To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM>
Date: Monday, June 05, 2000 12:50 PM
Subject: Pitted Heads
I am rebuilding a engine core 1.9, and both heads look OK but both pitted.From the archives,and what I intend to do,take to a shop,rebuild,and jb weld the pits.
Can you tell me your experience you have gone this route?
Thanks
Gerry
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