Subject:           Excessive crankcase pressure
     Date:           Sat, 20 Jul 2002 12:27:20 -0400
    From:           pabloantoine
       To:           ozbrick
 

850 n.a, 76.000 miles, gearshift.

It seems that Volvo induced all mechanics in the world to overfill this
engine with oil, because all tables (including the manual) specify 2
possible ammounts (5.1 and 5.6 qts), so they prefer to be sure and
always pour 5.6 qts.

After 70.000 miles the rear oil seal is shot because of constant higher
oil pressure than normal. Driving at 3500-4000 rpm will throw out huge
ammounts of oil through the rear oil seal. I lost half a liter in 300
miles and a lot of it I found sprayed on the undercarriage, even on the
rear axle(!!) by the air draft at high speed. Stop deluding yourself
with pressures and further subtle observations. Stop cleaning the
useless flame trap (you can elliminate it as well for a test and oil
will still leak under the car) and don't even think to change or reroute
the tubings. You risk compunding the trouble. This is a very good car
with 5-6 weak points, so find those and don't touch the rest.

The rear oil seal on these engines is shot at 70.000 miles, period.
Yes, you should change the rear oil seal, and yes it's very expensive to
separate the transmission from the engine (around $800). A worn rear oil
seal will not only waste oil, but will also scrape a channel in the
steel of  the crankshaft. The next (new) oil seal will have trouble
filling it to prevent further oil leaks, so don't postpone too long.

Look also at the bright side, especially those with clutch/ gearshift.
Change the clutch bearing and disk at the same time, because they are
also shot at 75.000. It cost me a total of $1200 in Wash DC at an expert
Volvo shop (the dealer wanted around $1600). The car doesn't consume any
oil now and runs great.

Further, buy yourselves a hand pump to draw oil from the crankcase after
each mechanic who overfills, and bring it back to the right ammount. The
car shoud be absolutely horizontal to measure it, because it's a
transversal engine and easily the oil dipstick shows huge differences
with the car on a slope or at horizontal to begin with. Mechanics are
very hostile sometimes at pointing them the overfilling, so do it
yourself. I found a good pump for $10 and connected a short transparent
hose not longer than the dipstick and thin enough to fit in the pipe
down to the crankcase. I pulled out the extra oil until I got it right.
It's clean and and easier to discard the extra oil from the pump than to
crawl under the car.

I also have a 740 GLE with 120.000  miles and can tell you I never had
such problems on it, but that is a different car, with older and more
reliable technology,  but outdated from many points of view.