Date: Sun, 31 Dec 2006 12:10:26 -0500
Reply-To: Geza Polony <gezapolony@SBCGLOBAL.NET>
Sender: Vanagon Mailing List <email@example.com>
From: Geza Polony <gezapolony@SBCGLOBAL.NET>
Subject: Re: Manifold vacuum specs?-Leak down testing
Thanks for the reply, Dennis. Your comment that "loosening the lifters may
provide temporary relief," etc., makes sense and is something I didn't find
after looking at many, many pages on hydraulic lifters.
The engine makes a kind of blap-blap sound, ie. compression or exhaust,
under load. Now that I got the FPR vacuum hose put back on, it idles well
except that it's slightly uneven, like missing a beat every few measures.
Also there are drips of water (no coolant smell) coming from either end of
the catalytic converter in the morning. ?
If there's a worn valve guide, bad rings, or the like, will this cause
catastrophic failure on the road, or can I just keep driving it as is, with
slightly reduced power on the hills and the blap-blap noise?
The issue is money, of course.
If a leak-down test shows the valves or guides to be faulty, how about
having the heads redone by a local machine shop rather than buying
rebuilt--the old way?
On Sat, 30 Dec 2006 23:26:36 +0000, Dennis Haynes <dhaynes@OPTONLINE.NET> wrote:
>A proper leak down test will tell you all you need to know. After measuring
the leak down, wit the engine restrained, you can by pass the tester and
directly pressurize the cylinders with shop air and you will be able to hear
where the internal leakage is occurring. Remove the airflow meter and
coolant pressure cap while doing this. If the air forces coolant out of the
expansion tank, then you know you have an internal leak. If you hear air
leaking through the crank breather, it is getting past the
pistons/rings/some leakage is normal past the ring gaps. If your hear
leakage through the intake, you have an intake that is not seating and if
through the exhaust, bad exhaust valve.
>Poor valve seating is usually the result of worn guides. Loosening the
lifters may provide temporary relief but this is not the fix. If the lifters
are not noisy, it is unlikely they are a problem unless you excessively high
oil pressure or weak valve springs.
>----- Original Message -----
>From: Geza Polony
>Date: Saturday, December 30, 2006 12:31 pm
>Subject: Manifold vacuum specs?
>> I've been trying to sleuth out yet another prob on my '84 1.9:
>> erratic idle,
>> compression noise under load, low (er) power on hills, harder
>> starting when
>> hot. I'm toying with the idea that there's a lifter problem, a valve
>> problem, or worse, ie., rings or head gaskets.
>> Now. I went out and got a vacuum guage and compression tester.
>> However, I
>> can't find the correct specs for vacuum readings ANYWHERE in the
>> Bentley or
>> the Haynes manuals. Am I missing something?
>> Nearest I can find, searching the archives, is that 8 in. is too
>> low. Is
>> that right? What's the acceptable range?
>> What else am I looking for in this vacuum test? Just vacuum level?
>> Is there a way to pinpoint problems with it, or does it just
>> tell you
>> "there's a problem?"
>> I want to try backing out the valve adjustment screws to give a
>> .06 lash as
>> suggested by some of the heavyweights here (and in Bentley) but
>> understandit's better to read vacuum and compression before and
>> Thanks to all--