I had the same problem with an engine in my 94 contiental town car after using castrol syntec exclusively. It turned out that the oil had no detergents and tiny black carbon particles built up on the oil pump intake screen until it completely blocked the pickup. By the time the oil light came on the engine was trashed.

I found a huge number of reports of similar problems and tried to go after castrol. They claimed we had contaimnated the oil with antifreeze. I had three labs test the oil to disprove that but in the end my attorney said they'd bankrupt me to fight the case in court costs so we dropped the issue.

Castrol took the oil off the market about three months after that and reintroduced it later as a blend with a detergent. I'll never run a synthetic in any engine of mine again.

Just a thought,

I've heard of oils having greater problems after adding additives due to an adverse reactions with contamints in the oil.  Perhaps some of the additives in the Exxon Elite caused an adverse chemical reaction with the residual oil from your previous oil change.  In my oppinion, practical implementation of chemistry is more of an art than a science.

Just for giggles,

Was the mechanical fuel pump checked for leakage?

Just last week I had a cardinal with a bad fuel pump diaphram.

A leaking fuel pump would certainly break down the oil and lead to accelerated engine wear.

Cheers,
RH

I hate to throw a wrench in this discussion, but all of the aviation oils are good.  Pick one you like for whatever reason you like it--including label color and design--and change it and the filter frequently.  Personally I use a straight weight AD oil because recent research from GM indicates that the straight weight oils do a better job when an engine is run at high power (like we do in aviation engines).  The multi-weights do fine in cars since they run at such low power settings.  Even with that, I am convinced that any difference between the multis and straights is minor.  If you fly regularly, there is no reason I know of to use the more expensive semi-synthetics.  They've not been around long enough to really make any valuable judgement.

There is the very off-chance possibility that you got some oil from a bad batch, but that would be a stretch.  I strongly suspect that something else is going on and the fuel pump thought is a very good place to start.

Walter Atkinson
Advanced Pilot Seminars