<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by johnlear &raquo;</TD></TR><TR><TD CLASS="quote">Had a 1990 model Cressida (3 litre straight six twin cam) that had horrendous internal gunk build up (I mean really bad).</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by King V &raquo;</TD></TR><TR><TD CLASS="quote">It makes you wonder if maybe Toyota or Audi are running their engines on the "too hot" side of things.</TD></TR></TABLE>

johnlear, that straight 6 you mention is an iron block motor correct? I wonder if heat has something to do with it, seeing how iron does not have the same cooling ability as aluminum. That said, most if not all of the Toyota sludge motors talked about in this thread are aluminum. Go figure.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by johnlear &raquo;</TD></TR><TR><TD CLASS="quote">On the other hand my CB7 Accord is clean as a whistle inside, I wonder if Honda's use of an oil cooler / heater (oil to water heat exchanger) at the filter attachment helps reduce sludging?</TD></TR></TABLE>

Pretty sure the don't have oil coolers, I could be wrong though. Honda engines are famous for their cooling abilities, maybe thats why the don't sludge up so easily.

 

strait six - iron
4cyl 5SFE - iron
6 cyl 1MZ/3MZ - aluminum
those are the sludgers and they will generally run forever if taken care of.

 

I have trouble leaving my synthetic oil in there not much long past 5000 km. the contamination alone in the oil at 12k would make me wonder.