Date: Mon, 7 Apr 2014 20:14:00 -0500
Reply-To: JRodgers <jrodgers113@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: JRodgers <jrodgers113@GMAIL.COM>
Subject: Re: The Head is Off, Assume Cracked?
In-Reply-To: <BAY407-EAS26B703171C202B382984E2A06B0@phx.gbl>
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Dennis,
Testing with the brake cleaner is one I have not tried. Didn't know
about it. Very good one. Thanks for posting that.
John
On 4/7/2014 7:11 PM, Dennis Haynes wrote:
> Here is the poor man's method of finding head cracks.
> Get some cans of brake cleaner, preferably nonflammable and non-foaming.
> With plug in place set up head with combustion chamber facing up. Fill each
> chamber with the brake cleaner. It should hold it. Leaky valves will be
> evident. If the cleaner goes into the coolant chamber test is done.
> Then for the valves that hold, turn the head so the intake ports face up.
> Fill the ports. Anything that leaks without going past a valve is a problem.
> Then stand the head up and test each exhaust port.
>
> I have seen heads crack in all sorts of ways. I had one van where both heads
> cracked right across the top from an outer head nut hole through both spark
> plug holes right to the opposite side. A good cleaning will also help find
> these. A local machine shop can tank clean the heads for a few bucks. But if
> you fail the first tests then you are done anyway.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Paul Smith
> Sent: Monday, April 7, 2014 10:45 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: The Head is Off, Assume Cracked?
>
> This thread really started about a week ago, as detailed in my post on March
> 30th: "Replacing the Head Gaskets (Maybe the Head)?" - so I won't repeat it
> all here. The vehicle is an 1989 Westy, 2.1 WBX, started with white smoke a
> few minutes after startup, returned to the driveway and later when I pulled
> the spark plugs I found coolant in the passenger side front cylinder.. I did
> manage to get the passenger side head off, going slowly and carefully and
> with the expected pain points (exhaust system, etc.). The problem cylinder
> was the front cylinder and it was stuck firmly to the head, requiring use of
> the methods noted in Bentley and on this list to finally free it. The
> sealing o-ring at the top of the front cylinder looked damaged (or
> deteriorated) compared to the same o-ring on the rear cylinder, which
> appeared to be in good shape. I thought I might have a cause, except that
> the compression gaskets in the head both looked good, no apparent damage or
> discoloration. I have no evidence that the coolant system was being
> pressurized by exhaust gases, only somehow coolant was entering the front
> cylinder. I don't see any cracks in the cylinder head combustion area
> (hairline or larger), although I have not cleaned all the carbon deposits
> off. Both exhaust ports look about as expected, fine coating of black
> carbon, with the front port slightly "damper" or more oily. The intake ports
> revealed an oddity. The rear (good) intake port looked about as expected,
> clean metal with a light oily sheen. The front (bad) cylinder intake had a
> coating of grey slimy stuff covering a good part of the back curve of the
> intake passage and up around the valve guide area. I was wiping it out
> without thinking how odd it was (long day) when I stopped. It seems unlikely
> that coolant would be blown up into the intake from the cylinder (valve is
> primarily open on the downstroke), but coolant leaking into the intake
> passage would certainly be sucked into the cylinder. If it were being
> sprayed in from crack in the head it might also form a coating on the hot
> intake passage walls. I guessing that this may have been developing over
> time, as Dennis Haynes mentioned. I took a close look at the piston tops -
> the rear had a light coating of combustion/carbon deposits; the front piston
> had some, but is fairly clean (steamed clean?) in the center portion. The
> cylinder walls look good in both, smooth, unscored and not scorched or
> discolored.
> Has anyone experienced a crack like this in the head into an intake passage?
> I can't see anything obvious, but without removing the valve and getting a
> good view angle I might not. Still might not find anything visually in any
> case. I tried briefly to block all the coolant passages and apply pressure
> to detect a leak - couldn't get a good seal. All this is being done in my
> driveway, no garage, so my shop facilities are limited. I can't understand
> how a grey coating could be formed in the front cylinder head intake passage
> without a leak of some kind, along with the clear entry of coolant into the
> cylinder. Both intake tubes upstream of the head seem fine (the same). The
> driver side intakes are also fine.
> It seems like a replacement head may be the best option at this point. I'm
> not sure I can find the cause, although it pretty clearly appears to be in
> the head. I would rather install a new head than try any partial repair or
> patch. Then if I get curious enough I can pull apart the bad head and see
> what I find.
> Thoughts?
>
> Thanks,
> Paul
>
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