Date: Wed, 26 Jan 2011 10:37:22 -0800
Reply-To: Roland <syncronicity1@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Roland <syncronicity1@GMAIL.COM>
Subject: Re: Last gasp: low compression exhaust valve can't pass smog
In-Reply-To: <AANLkTikoljmqjB7KPO2YJcMJngixhbJxJoH33y59Hsut@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Ok, so this is the end of the long tale, have been going on for well over a
year, trying to identify the proper pool of $ to make a permanent repair.
The summary:
- 2.1 WBX wouldn't pass smog, failed hydrocarbons at idle. The most likely
reason it was missing; due to low compression in one cylinder. Leakdown
test indicated bad exhaust valve.
- Finally brought it to a shop and had the head replaced, it passed smog!
Yes, I can be legal again!
Other notes:
- the shop did another compression test: 60 lbs (so onward with the head)
- final smog numbers (flying colors)
- at Idle: HC = 28 PPM (Max is 120), CO% = 0 (Max is 1.00)
- at 2500 RPM: HC = 15 PPM (Max is 180), CO% = 0.02 (Max is 1.00)
- So this baby should be in good shape! They had to adjust the idle
switches, timing, (way off) and other things that were last set by another
shop [ I don't get this, I sometimes worry when one expert has to correct
the work of a prior expert, both are VW only repair shops].
- As a low cost attempt, I had installed the "non-California" version of a
Cat, around $136 at Van Cafe. Evidently the official California certified
cat is now something around $400. But the point is it passed with this
"all-states" version and I doubt any smog check station will ever know the
difference.
- Probable root-root cause, the engine overheated twice about 2 and 4 years
ago. Once the water pump blew on the freeway, the other that little plastic
coolant junction box at the firewall blew. Each time all coolant drained
out. Both were on the freeway (lights / buzzer blaring) and I kinda pushed
it just a few more hundred yards to get to a safe place both times. That
might have caused some overheating and damaged the valve.
Anyway, happy now, thanks for all your past support, and it was true what
you all said, that I need to get the valve fixed.
Roland
On Thu, Jun 17, 2010 at 4:33 PM, Roland <syncronicity1@gmail.com> wrote:
> Ok,
>
> So, again trudged to the smog station after various lower cost attempts
> (California).
> - High HC at idle, 270 PPM and more. The max allowed is 120.
> - HC at 2500 RPM is fine (because of course the compression happens at that
> speed).
>
> Apparent root cause: exhaust valve, cylinder #4
> - compression is in the 85 lb range, vs the others in the 130-145 lb range.
> - leakdown test said "84% out of exhaust".
> - I can see / feel/ hear an occasional miss at idle (I think).
> - So it seems pretty clear that lower compression / miss will cause high
> HC.
> - It runs fine, last weekend just did a 270 mile trip.
> - Root cause of bad valve? Don't really know, the engine has AMC heads,
> vehicle has over 200K miles, so obviously the heads were redone at some
> point. About 4 years ago I blew the water pump on the freeway, didn't turn
> it off right away, but also passed smog after that event. Maybe just more
> time caused the valve to go bad. But I believe I've also read that the
> valves in AMC head go bad faster than expected. Also, the upper bolt is
> missing from where the exhaust manifold / header attaches to #4, but I can't
> feel any air/exhaust flow -- maybe the lower bolt is holding the gasket.
>
> Potential paths:
> - get the left side head replaced, not sure I am willing to do it myself,
> tough to get at, seems like many peculiarities on this one, I may screw
> something up. ( I would if I still had my Austin Healey). The 2 shops I
> spoke with would use a new head, from their estimates it must be many hours
> of labor.
> - go to the California Carb appeals to the referee. I have the papework, I
> think I've spent enough $ that they may give me a 1 time waiver. (i.e.
> delay facing the problem, but I am planning some trips, I don't want this
> engine to go bad this summer.).
> - get both heads replaced while we are at it? (I don't have all the
> records, but the bottom end probably has 200K + miles on it.)
> - costs just go up from there.
>
> Anybody have any ideas at all high I could get past the smog test without
> replacing the head?
>
> Thanks!
> Roland
>
>
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