Hmmm..... .  My 1991 Volkswagen Vanagon GL Campmobile original 2.1 L waterboxer engine exhibits this phenomenon year round.  I am reluctant to use a lighter weight oil, whether multi-grade or single grade, than the 20W-50 that I use in summer.  I want that -50.  Before I installed an external oil cooler (Ten Cent Life), whenever I pulled off the highway after a long run in hot weather, the idle oil pressure would drop below 5 psi, enough for the oil light to come on at idle.  Please don't tell me that ambient temperature does not affect oil pressure when the engine is hot.  I realized very graphically that it does when I drove into a thunderstorm on Raton Pass from 105 F ambient to 45 F ambient quite suddenly.  The oil pressure rose quickly from around 25 psi to around 55 psi.  Same gear, same speed.

Since the lifter clatter stops quickly after I drive a block or so (or let the engine idle a few minutes if it is really cold out), I don't worry about that.

mcneely

---- OlRivrRat <OlRivrRat@COMCAST.NET> wrote:
>         If you Switch to a 10 or 5 or even 0W** Oil that ColdLifterSyndrome will most probably be diminished or
>
> may even go away completely ~
>
>                                                                         ORR ~ DeanB
>
>
> On 25 Feb , 2014, at 2:58 PM, Steven Shelton wrote:
>
> > I drove it around for a while and now the noise is tolerable.  I'd never
> > heard it that loud.  I let the oil drain overnight before I refilled it;
> > maybe that had something to do with it.
> >
> > Well, I spent half the day trying to fix a starting problem, didn't find
> > anything wrong, and now it starts fine.  Not very satisfying.  Thank you
> > all for your suggestions, though.  Just knowing there are people out there
> > with a lot more knowledge than I have gives me the confidence to attempt
> > these repairs.
> >
> >
> > On Tue, 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.
> >>>
> >>>
> >>> On Tue, Feb 25, 2014 at 2:25 PM, Dennis Haynes <d23haynes57@hotmail.com>
> >>> wrote:
> >>>
> >>> Intermittent problems are often elusive. Will it start reliably with the
> >>>> AFM
> >>>> disconnected? If yes then you do have a mixture control issue and the
> >>>> sensor
> >>>> being disconnected is helping get past it. I would look for massive
> >>>> vacuum
> >>>> leaks and wiring issues. Except for the O2 sensor which is a
> >>>> "consumable",
> >>>> it is very rare for any of the other sensors to go bad. Again, the
> >>>> connectors and wiring is more often the real problem.
> >>>>
> >>>> Dennis
> >>>>
> >>>>
> >>>> -----Original Message-----
> >>>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> >>>> Of
> >>>> Steven Shelton
> >>>> Sent: Tuesday, February 25, 2014 2:12 PM
> >>>> To: vanagon@GERRY.VANAGON.COM
> >>>> Subject: Re: Engine Starting Problem
> >>>>
> >>>> I meant that the engine turns over and over but it will not start/run.  I
> >>>> checked the intake air sensor (Bentley 1999 edition pg 24.28):
> >>>>
> >>>> 2-3        556
> >>>> 6-9        557
> >>>> 6-22      2697@18 degrees C
> >>>> 2-3 and 7-9:  ohms change as I moved the sensor plate
> >>>>
> >>>> Is this a definitive test or could there still be something wrong with
> >>>> intake air sensor?
> >>>>
> >>>>
> >>>> On Tue, Feb 25, 2014 at 1:59 PM, Dennis Haynes
> >>>> <d23haynes57@hotmail.com>wrote:
> >>>>
> >>>> Cranking and starting are two completely different issues. The starter
> >>>>> will crank (turn)the engine over if you removed the complete fuel
> >>>>> delivery system and put it out to the garbage.
> >>>>> Check the wiring on the back of the starter. The solenoid trigger wire
> >>>>> may be loose and you're working near there is making or breaking that
> >>>>> connection.
> >>>>>
> >>>>> Dennis
> >>>>>
> >>>>> -----Original Message-----
> >>>>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> >>>>> Behalf Of Steven Shelton
> >>>>> Sent: Tuesday, February 25, 2014 1:18 PM
> >>>>> To: vanagon@GERRY.VANAGON.COM
> >>>>> Subject: Re: Engine Starting Problem
> >>>>>
> >>>>> OK, as I said above, the engine would not crank at all, even after
> >>>>> returning to it using a charged battery the next day.  As soon as i
> >>>>> removed the AFM, even with the #1 spark plug removed, the engine
> >>>>> cranked right up.
> >>>>>  I checked the ECU connector, with the following results:
> >>>>>
> >>>>> 2-7     3213 ohms@16 degrees C
> >>>>> at this temperature the reading should be 3000 ohm to 3500 ohm.
> >>>>> I also checked at the temp 2 sensor, it was 3178 ohm.
> >>>>>
> >>>>> Other readings were:
> >>>>> 1-7     10.64 V
> >>>>> 5-7      infinity
> >>>>> 6-19    558 ohm
> >>>>> 7-25      0 ohm
> >>>>> 11-7     14.9 ohm
> >>>>> 12-7     15.1
> >>>>> 14-6     3154 ohm
> >>>>> 15-19     555 ohm at rest, it moved up when I moved the plate
> >>>>>
> >>>>> Does this mean conclusively that the temp 2 sensor is OK?  Any
> >>>>> suggestions on what to try next?
> >>>>>
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>

--
David McNeely