Re: Is it too late to switch to synthetic?

[Zsolt Kovacs <zsolt@telusplanet.net>]

I switched over to synth at about a 185k km, after I had similar concerns you do.
Since then I drove about 5-6k km and my car did start leaking at the valve cover
gasket. I haven't noticed anything else yet but it may still happen. Here is a
copy of a response that Ted Kublin sent me.

Subject:
        switchover
   Date:
        Fri, 27 Nov 1998 10:51:45 -0500
   From:
        Ted Kublin <Ted.Kublin@msfc.nasa.gov>
     To:
        Zsolt@telusplanet.net

Zsolt,

I work as a propulsion engineer and have been using synlubes for twenty
years ....

The only "problem" with switching over a high mileage car to synthetic
lubes is that you MAY experience some leakage - especially if the vehicle
hasn't had frequent oil changes. The reason is that with petroleum lubes
you tend to build up a layer of sludge/varnish on seals/gaskets ...when
these elastomeric (synthetic rubber) seals are no longer exposed to the
circulating oil, they have a tendency to dry up,shrink and eventually
crack.  If you put any synthetic oil in an engine/transmission in this
condition, the added detergency/solvency of the oil will gradually clean
out these deposits and expose the shrunken/cracked seals - hence you can
get some seepage past the seals.  If the vehicle has been well maintained
there generally isn't a problem ...I sell synlubes on the side,so I have
quite a bit of experience with this problem. If nothing else I'd go ahead
and put a new valve cover gasket on - this is a common leakage site;along
with the seal under the oil filler cap.

In any case,you need to change filters FREQUENTLY with the first batch of
synthetic oil you run in the engine, as the sludge deposits loosened up
will quickly load up the first 1-2 filters you put on.  I'd recommend
changing the first filter after 1500 miles; changing the second one @ 3500
miles and changing out the first batch of oil @ 6000 miles - don't forget
to top off the crankcase after doing the filter changes.  After you get the
engine clean you can run 7500 miles/6 months between changes, using a 100%
synthetic.  I'd recommend using either Amsoil or Mobil 1 (0w-30 or 5w-30 in
winter; 10w-40 or 15w-50 in summer), along with the OEM VW/Audi filters.

Sincerely,

Ted


BustnJustn@aol.com wrote:

> Hi all,
>
> I own a 90 V8q with 117k.  The PO was very meticulous about the maintenance of
> the car, however choose to use dino rather than synthetic oil.  I have used
> synthetic exclusively in every car I purchased new, and have never had a
> problem.  I have been informed that by switching to synthetic in a used car
> that it will create leaks as the synthetic is slipperier than dino and will
> seep through the seals.  I would like to switch to synthetic but not at the
> cost of leaks.  Can any of you dispute or verify the information that I
> received?  Any BTDT's?
>
> Any information would be appreciated.
>
> Thanks in advance,
> Justin
> 90 V8q