Oil Light

I took a look at the oil pressure sending unit a day ago and saw that
it was slightly leaking oil. Later this week, I'm going to Napa to pick
up a new oil sending unit for the light.

The engine in my car was replaced over 2.5 years ago. The engine that's
in there now is a used (junkyard) engine. As far as how the engine
sounds, it makes somewhat of a ticking sound in the head at idle (which
remained even after the valve job and head gasket replacement). The
mechanics told me not to worry about it. Also, there is what appears to
be some wristpin noise (which occurs only before the engine warms up).
There's no bottom end noise as far as I can tell, though. For the last
2.5 years, I've always done my oil changes on time and used Mobil 1
full synthetic with high quality filters everytime ever since the
current engine has been in my car.

A mechanic told me that having too high of an oil pressure can like
blow out seals or something. How high does the oil pressure have to be
before you have to worry about blowing oil seals?

wrote:
> A mechanic told me that having too high of an oil pressure can like
> blow out seals or something. How high does the oil pressure have to be
> before you have to worry about blowing oil seals?
>

I can't think of a single seal in most older (pre- 1990) Mopar engines
that is exposed directly to the gallery oil pressure. The rear main gets
somewhat "sprayed" by oil squirting out of the rear main bearing, but
its not a direct seal. The front seal is not even sprayed in the v8s and
slant-6 because the cam drive gear is in the way. The 2.2/2.5 may spray
the front seal just like the rear seal, but it doesn't hold back the 60
PSI pressure.

The only thing I would worry about from excessive oil pressure in a
Mopar engine is twisting the oil pump drive shaft if its not a heavy
duty drive shaft. With 60 psi at high speed, you're fine with all stock
components. My 440 pumps up a little over 80 psi when its cold (and I
don't rev it up much when cold because of that) but that is with a
high-volume oil pump and a hardened oil pump drive shaft.

On Tue, 27 Jun 2005 wrote:

> I took a look at the oil pressure sending unit a day ago and saw that it
> was slightly leaking oil. Later this week, I'm going to Napa to pick up
> a new oil sending unit for the light.

That stands a high likelihood of solving your problem.

> The engine in my car was replaced over 2.5 years ago. The engine that's
> in there now is a used (junkyard) engine. As far as how the engine
> sounds, it makes somewhat of a ticking sound in the head at idle (which
> remained even after the valve job and head gasket replacement).

Cam followers, don't worry about it.

> some wristpin noise (which occurs only before the engine warms up)

Completely normal with this engine

> 2.5 years, I've always done my oil changes on time and used Mobil 1 full
> synthetic with high quality filters everytime ever since the current
> engine has been in my car.

Good work. If you're trying for maximum engine life, be advised you can
use the large Wix 51515 (NAPA Gold 1515) oil filter on this engine in this
car. Also make sure to keep your PCV system *in its entirety* serviced
properly; see http://tinyurl.com/yr2pg .

DS

writes in article .com> dated 27 Jun 2005 23:47:53 -0700:
>A mechanic told me that having too high of an oil pressure can like
>blow out seals or something. How high does the oil pressure have to be
>before you have to worry about blowing oil seals?

I blew out something (rings I think) in a 351 winchester by putting too much
oil in the engine. The theory is that when the piston comes down into
nothing but incompressible oil it creates a *lot* more blowby pressure than
a regular pump would.

Maybe somebody else can explain it better, but as long as you have the
correct amount of oil, the pump can't be "too good". If you do get a
super-high pressure reading, maybe there's another problem, like a blocked
line...

-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer.

On Tue, 28 Jun 2005, Spud Demon wrote:

> I blew out something (rings I think) in a 351 winchester by putting too
> much oil in the engine. The theory is that when the piston comes down
> into nothing but incompressible oil it creates a *lot* more blowby
> pressure than a regular pump would.

Fascinating, but in order to be believable:

1) There'd have to be such a thing as a "351 winchester", which there is
not. 351 Cleveland, 351 Windsor, 351 Modified, but no "351 winchester".

2) You'd have had to put in several GALLONS too much oil in order for the
"pistons to come down into nothing but incompressible oil".

> as long as you have the correct amount of oil, the pump can't be "too
> good".

Incorrect.


> The above may not (yet) represent the opinions of my employer.

Geeze, I hope they don't, 'cause if they do, your employer is a true
dum-dum.

The other day, I bought another sending unit from Napa. I replaced it
today after work. So far, no more oil light. ;-)


Steve wrote:
> wrote:
>
> > I just put an oil pressure gauge on there (used T-Fitting to fit gauge
> > and oil light switch on engine) and went driving around for a little
> > while. After driving for about 20 minutes, I noted the following
> > readings on my oil gauge:
> >
> > Hot Idle (in drive): 17 Pounds
> > Hot Idle (in Park): 24 Pounds
> > 2000 RPM: 40 Pounds
> > 3000 RPM: 50 Pounds
> > 4000 RPM: 60 Pounds
> >
> > My observation is that my oil light (the teapot) seems to kick on when
> > my gauge gets below 18 Pounds.
> >
> > Is 17 Pounds of pressure at hot idle ok?
>
> that's an excellent number. You've got a bad sending unit on the idiot
> light.
>
> >
> > How many pounds pressure is supposed to kick on the teapot light?
> >
>
> Around 3-5 PSI.