Date: Tue, 25 Feb 2014 18:28:54 -0800
Reply-To: Stuart MacMillan <stuartmacm@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stuart MacMillan <stuartmacm@GMAIL.COM>
Subject: Re: Mann Oil Filter and lifters Was:Engine Starting Problem
In-Reply-To: <8336BFC0-455D-446C-8225-EBF6722A6AE9@comcast.net>
Content-Type: text/plain; charset="us-ascii"
I don't buy that one either, I've used the Mann filter for 250,000 miles
and have always had this issue. It's a chronic Vanagon problem engineered
in at the factory as far as I can tell. One rebuilt engine with new lifters
and cam I had once did it from day one.
What you are hearing is caused by the lifter internal oil leaking down,
shortening the distance between the top the cam lobe to the normally open
valve that is now closed. It's effectively setting your valve lash to the
same distance as the cam lift.
When you fire it up, the lifter is kicked violently off the cam lobe since
there is no valve spring pressure on it, and is thrown into the pushrod,
which then hits the rocker arm, which then hits the valve stem, all of which
makes a very loud tapping sound.
It's not great for anything, so the best thing is to drive off and stay in a
lower than normal gear to keep the revs up and pump it back up. Keeping the
revs up around 3000 rpm maximizes the oil pressure and lets the lifter
"float" and not hit the cam as hard until it eventually pumps up. You'll
see it's less noisy at high rpm for this reason.
My old '85 can take up to 15 minutes on the freeway to pump up. At least
it's only one lifter that leaks down, so it doesn't happen all the time,
only when that lifter is at the top of the cam on shutdown. If I wanted to
prevent it, I could rotate the engine to the timing mark where it's not on
the open valve when I park it for a long time. Yeah, right, I might learn
to play the piano too someday.
Stuart
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Eric Caron
Sent: Tuesday, February 25, 2014 3:29 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Mann Oil Filter and lifters Was:Engine Starting Problem
My van sits a long time between starts. How would this filter help and
would it work with mobile 1 Synthetic?
Eric Caron
85 GL Auto
On Feb 25, 2014, at 3:59 PM, JRodgers <jrodgers113@GMAIL.COM> wrote:
> Having a Mann oil filter will help prevent this.
>
> John
>
> On 2/25/2014 2:28 PM, Steven Shelton wrote:
>> This is turning into a real nightmare. I reinstalled the AFM; now it
>> starts fine, but the engine makes a loud clattering! It's done this
>> occasionally over the years, but always went away pretty quickly. Now it
>> won't stop. I've gone over it with a stethoscope and it seems to be
>> loudest at the driver's side of the intake air distributor, but it's hard
>> to pinpoint. I disconnected the fuel injector plugs and cranked the
engine
>> to see if something was bouncing around in a cylinder, but heard nothing.
>> Can all this be related? It all started off with a shorted oil pressure
>> sensor wire.
