Date: Thu, 9 May 2013 17:19:15 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: coolant overflow fears and thoughts-Some more thoughts!
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One problem with relying on the sniffer tests is that they are looking for
un-burned hydrocarbons. In order for this to work in addition to the leak
you also need a combustion failure in the leaking cylinder. While cracked or
loose heads may also cause a combustion issue you are in deep trouble by the
point the sniffer tests pick it up. Keep in mind if those gasses can get out
in some cases coolant can get into the cylinders. Antifreeze into the
cylinders and then into the oil can cause some real damage. Long before
antifreeze in the oil is visible the stuff becomes extremely corrosive and
can quickly destroy bearings along with crank and cam surfaces. It can also
destroy pistons by blowing out the tops and destroying the ring lands.
If the engine has ever been overheated, (even before a rebuild) or has had
the heads off for any reason loose heads can be the cause. I probably have a
better than 50-50 success rate in fixing these issues just be retourqing the
heads if the problem has not been left so long that the head seals (inners)
or the tops of the cylinders have burned or pitted away.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Tom Carchrae
Sent: Thursday, May 09, 2013 1:08 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: coolant overflow fears and thoughts
Thanks Larry!
Sadly, when I checked my van the other day after going up a somewhat serious
hill and I saw some small amount of bubbling in the tank behind the license
plate when it was idling - so I suspect there are combustion
gasses coming through. :/ I'd like to do the sniffer test again. Is
there any chance this could be coming from anything natural - eg, like
steam/water vapour from the coolant? Engine was probably on for about
15 minutes in total - warm enough to get up to full operating temperature,
but not for any length of time.
I'm torn on what to do. I really don't have the time on my hands to do a
full engine removal and disassembly ala
http://www.thesamba.com/vw/forum/viewtopic.php?t=286798 - so do I keep
driving it gently with this knowledge and wait until it gets so bad the
engine overheats?... I suspect it'll get worse over time and force me
to fix it.
Tom
On 13-05-08 03:00 PM, Larry Alofs wrote:
> Tom,
> If you (or anyone else) would like to make an adapter to test
> pressure caps, get this fitting from Stant:
>
> http://www.amazon.com/Stant-12017-Threaded-Radiator-Cooling/dp/B000CKT
> JYG
>
> Or search for Stant 12017
>
> Its two male ends let you attach the cap under test to another old cap
> that has had the valves removed. Then you just need a way of applying
> and measuring pressure.
>
> Larry A.
> finally found the box with that stuff in it
>
>
>
> On Mon, Apr 29, 2013 at 12:51 PM, Tom Carchrae <tom@carchrae.net
> <mailto:tom@carchrae.net>> wrote:
>
> Roger: Yeah, I want to build a tester gizmo. I also have a PSI
> guage that
> I was thinking of plumbing into the cooling system - I have not gotten
> around to it though!.... how did you build yours? I was thinking
> the best
> design would be an old expansion tank and a bike pump.
>
> Larry: I've only done the cursor blowing through the cap. I know
> it holds
> pressure (loosened it while warm!), and I know it can let
> fluid/air in/out.
>
>
> Yes, pressure caps are cheap, but the rest of your cooling system +
> radiators, etc are not. I think a cap tester is a good preventative
> investment. The quality of caps seems all over the place.
>
>
>
>
> On Mon, Apr 29, 2013 at 9:32 AM, Roger Barkley
> <rvbarkley4347@gmail.com <mailto:rvbarkley4347@gmail.com>>wrote:
>
> >
> > New pressure caps can be bad. I was suspect of my old one so
> ordered a new
> > one from GoWesty and installed. Thought I would test the old one
> so I built
> > a gizmo to test. It tested fine, just for kicks I tested the new
> one.....it
> > didn't start to bleed off untill nearly 30 #'s ! Returned it
> and put the
> > old one back on. Also went through two "new" front heater valves
> that
> > leaked after only a month or two. Went to VW for the third one,
> two years
> > and its still good. Moral.....be suspect of new parts...
> >
> > Roger B.
> >
> > From: Tom Carchrae <tom@CARCHRAE.NET <mailto:tom@CARCHRAE.NET>>
> > Subject: Re: coolant overflow fears and thoughts
> >
> > @Bill - I've blown through that pipe, it is not blocked. In
> fact, I used
> > it to drain the extra coolant out of the bottle. I wonder about
> it being
> > air tight though, although I've seen no leaks.
> >
> > @Dennis - Thanks. I've been tempted to build a cap tester just
> to confirm
> > my theory on that cap holding too much pressure. I ended up
> replacing
> > bleeder valve assembly, radiator, and at least one hose after
> that had
> > happened. The only other thing I can think of that may have
> caused the
> > pressure problems was a badly routed front heater bypass job
> (the heater
> > hose may have been pinched behind spare tire).
> >
> > I have done the combustion gas sniffer test, and it came out ok.
> I guess I
> > should have a compression and/or leakdown test done again and
> see if that
> > shows any signs. As you alluded, I suspect it may only be
> failing when
> > driving/under load.
> >
> > Any other ideas to confirm the issue before tearing the engine
> apart or
> > replacing... :/
> >
>
>
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