On 18 May 2006 at 0:27, Dennis Haynes <dhaynes@OPTONLINE.NET> wrote:

> -----Original Message-----
> Again, modern oils are highly engineered products-that work. Mixing
> different viscosity multi weights can make a real mess. There is nothing
> wrong with 75 psi on a cold engine. A few minutes will take care of that
> anyway. Just drive gently and avoid high revs until the temp gauge
> clears the white bar. Before the inline engines had hydraulic lifters,
> those engine ran at 90 psi hot! I would not worry about excessive oil
> pressure until you 100-125 and still climbing which would also indicate
> a relief valve problem. The Mobil 15w-50 is rated to flow down to -35F.
> I have used it as low as -4F.  In regular weather below the 20's I would
> use a 0w-40, (Mobil 1 European car formulae) or 10w-40, (Mobil 1
> extended performance). BTW, oil analysis is indication that a 7,500 mile
> change interval is the reasonable limit for the Water boxer.  Even the
> synthetic is suffering from oxidation and nitration, most likely due to
> high upper ring temperatures.

Dennis,

I'm always interested to read your replies, especially on subjects very relevant to me like oil
pressure. You're right on the mark with the comment about solid lifter I-4s - my '85 Jetta
1.6NA still holds 75psi hot at 3000rpm after 300k on it. By comparison, my rebuilt 1.6TD with
hydraulic lifters struggles to manage half that pressure... (hence the interest in this topic...)
I wish I'd put a gauge on my 2.1L WBX, but I drove it for 10 years and the light never came
on, so I guess it was ok... (used Mobil 1 15w50 or Amsoil 15w40 and Bosch/VW filters
always).

Shawn Wright
http://members.shaw.ca/vwdiesels
'88 Westy 1.6TD 5 speed
'85 Jetta Diesel 1.6NA