Oil pressure problem

I have a Bonanza V35 with a IO 470. Before and after engine overhaul the oil
pressure after the engine warms up goes just into the red. They have tried
turning the pressure up but this seems to only make the pressure go up when
cold. If the temperature outside is real cool the pressure goes over 200
psi. The engine builder said its in spec. I think there is a problem
somewhere. I want the oil pressure to run in the green. Does anybody have
any ideas on what could be causing this. I'm afraid its going to blow the
gage out one cold morning.
Thanks

On Wed, 3 Jan 2007 14:13:28 -0800, "Aluckyguess" wrote in
:

I have a Bonanza V35 with a IO 470. Before and after engine overhaul the oil
pressure after the engine warms up goes just into the red. They have tried
turning the pressure up but this seems to only make the pressure go up when
cold. If the temperature outside is real cool the pressure goes over 200
psi. The engine builder said its in spec. I think there is a problem
somewhere. I want the oil pressure to run in the green. Does anybody have
any ideas on what could be causing this. I'm afraid its going to blow the
gage out one cold morning.
Thanks


What is the oil pressure indication before it warms up?

I'm a little confused by why the pressure should be adjusted upwards
when it appears that your complaint is about it being too high, but
here are some ideas:

1. If it behaved that way before AND after the overhaul, the
source of problem may be in the metering circuit/piping (gage).

2. If the engine oil pressure is indeed too high, it may be the
result of an obstruction in the oil passages (sludge, foreign
object(s), that went unnoticed during rebuild.

Can you quantify the temperatures and pressures?

Have you considered contacting Lycoming/Continental?

Aluckyguess wrote:

I have a Bonanza V35 with a IO 470.

So you have an N35 or P35, a V35 has an IO520.


Before and after engine overhaul the oil
pressure after the engine warms up goes just into the red. They have tried
turning the pressure up but this seems to only make the pressure go up when
cold. If the temperature outside is real cool the pressure goes over 200
psi. The engine builder said its in spec. I think there is a problem
somewhere. I want the oil pressure to run in the green. Does anybody have
any ideas on what could be causing this. I'm afraid its going to blow the
gage out one cold morning.

How do you know the gauge is correct? Check that first.

"Larry Dighera" wrote in message
...
On Wed, 3 Jan 2007 14:13:28 -0800, "Aluckyguess" wrote in
:

I have a Bonanza V35 with a IO 470. Before and after engine overhaul the
oil
pressure after the engine warms up goes just into the red. They have tried
turning the pressure up but this seems to only make the pressure go up
when
cold. If the temperature outside is real cool the pressure goes over 200
psi. The engine builder said its in spec. I think there is a problem
somewhere. I want the oil pressure to run in the green. Does anybody have
any ideas on what could be causing this. I'm afraid its going to blow the
gage out one cold morning.
Thanks


What is the oil pressure indication before it warms up?

I'm a little confused by why the pressure should be adjusted upwards
when it appears that your complaint is about it being too high, but
here are some ideas:

1. If it behaved that way before AND after the overhaul, the
source of problem may be in the metering circuit/piping (gage).

2. If the engine oil pressure is indeed too high, it may be the
result of an obstruction in the oil passages (sludge, foreign
object(s), that went unnoticed during rebuild.

Can you quantify the temperatures and pressures?

Have you considered contacting Lycoming/Continental?

The pressure is to high when the engine is first started then when warm its
to low.
No I have not contatcted Lycoming but I will try.

"Newps" wrote in message
. ..


Aluckyguess wrote:

I have a Bonanza V35 with a IO 470.

So you have an N35 or P35, a V35 has an IO520.


Its an N model

Before and after engine overhaul the oil
pressure after the engine warms up goes just into the red. They have
tried turning the pressure up but this seems to only make the pressure go
up when cold. If the temperature outside is real cool the pressure goes
over 200 psi. The engine builder said its in spec. I think there is a
problem somewhere. I want the oil pressure to run in the green. Does
anybody have any ideas on what could be causing this. I'm afraid its
going to blow the gage out one cold morning.

How do you know the gauge is correct? Check that first.

Before and after engine overhaul the oil
pressure after the engine warms up goes just into the red. They have
tried turning the pressure up but this seems to only make the pressure go
up when cold. If the temperature outside is real cool the pressure goes
over 200 psi. The engine builder said its in spec. I think there is a
problem somewhere. I want the oil pressure to run in the green. Does
anybody have any ideas on what could be causing this. I'm afraid its
going to blow the gage out one cold morning.

Sounds like the relief valve is sticking. That'll cause low oil
pressure when hot and high when cold.

Dan

"Aluckyguess" wrote in message
...
I have a Bonanza V35 with a IO 470. Before and after engine overhaul the
oil pressure after the engine warms up goes just into the red. They have
tried turning the pressure up but this seems to only make the pressure go
up when cold. If the temperature outside is real cool the pressure goes
over 200 psi. The engine builder said its in spec. I think there is a
problem somewhere. I want the oil pressure to run in the green. Does
anybody have any ideas on what could be causing this. I'm afraid its going
to blow the gage out one cold morning.
Thanks

We need more details. In particular, is the oil pressure low at cruise RPM,
or just at idle RPM? How hot is the oil when you see these readings? The
spec's for my engine allow the oil pressure to fall to the very bottom of
the yellow arc, possibly into the red if the oil is hot and RPM are low.

Turning the pressure relief valve up or down only sets the maximum possible
pressure. It doesn't help boost pressure when the oil is hot. If you've got
it too tight, you may indeed get 200 PSI on start-up, but that won't do you
a bit of good once the oil gets warm. Once the oil is warm, pressure is
dictated by how "loose" your engine is. Turn the pressure relief valve back
to where it limits pressure on start-up to what the book recommends. You'll
be sorry if you don't - you'll damage something, possibly a filter, possibly
something internal to the engine.

KB

On Wed, 3 Jan 2007 16:03:33 -0800, "Aluckyguess" wrote in
:

The pressure is to high when the engine is first started then when warm its
to low.

Now I understand. How cold is it when you start? Perhaps you need an
engine heater in the winter. Where are you located. Is the aircraft
hangared?

You said it did this to high when cold and too low when warm syndrome
before the overhaul too?

What grade of break-in oil are you using?

No I have not contatcted Lycoming but I will try.

There's a trouble shooting guide he
http://www.lycoming.textron.com/main...ort/index.html

You may also consider calling the American Bonanza Society if you're a
member. They have offered a lot of good advice in the past regarding my
Baron, and have a lot of knowledge and expertise.

"Aluckyguess" wrote in message
I have a Bonanza V35 with a IO 470. Before and after engine overhaul the
oil
pressure after the engine warms up goes just into the red. They have tried
turning the pressure up but this seems to only make the pressure go up
when
cold. If the temperature outside is real cool the pressure goes over 200
psi. The engine builder said its in spec. I think there is a problem
somewhere. I want the oil pressure to run in the green. Does anybody have
any ideas on what could be causing this.

Start first by checking calibration on your oil pressure guage.
Then check the bypass valve for proper operation (a good rebuilder will have
replaced it).
Ask the rebuilder to see his records for bearing/crankshaft clearance
measurements because the pressure is going out the gaps.

I'm afraid its going to blow the gage out one cold morning.

More likely to blow out an oil cooler.

D.