[net.auto] Problem with 914

mcneil@lll-crg.ARPA (Mike McNeil) (08/02/85)

I recently bought a '75 Porsche 914 with supposedly 30k miles on a rebuilt
engine.  My problem is this: when I am going down a steep grade and take my 
foot off the gas, the engine begins to make a sputtering sound and sometimes
exhausts blue smoke.  This same sputtering effect happens intermittently
when I've been driving a while at highway speeds.  Someone suggested that
the pushrod tube seals could be bad.  Can anyone verify that this might be
the problem?

                                                        Mike McNeill

                                                        mcneil@lll-crg

zrm@prism.UUCP (08/04/85)

Your valve guides are worn, most likely. Try this: Accelerate to at
least 50mph and at least 5500rpm and take your foot off the gas
quickly. Look in the rear view mirror. What do you see? Nothing.
There is a big blue cloud blocking the view. If this is the case,
and if you are NOT consuming large amounts of oil, it is your valve
guides. If you are consuming oil as well, get the oil seals
checked. If they are OK then you have a more serious problem and
should go further and check your compression and any other potential
trouble spots.

You can live with worn valve guides for quite some time since they
neither eat lots of oil nor do they let contaminants into the oil.
If the engine is othwise in good shape and you are tired of seeing
smoke come out of your car, having the valve guides replaced (if
they are replaceable) should not be too costly, $200 to $300 I
imagine.

Zigurd R. Mednieks
Mirror Systems Inc.
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ZRM@MIT-MC