Low oil pressure, high oil temp?

[Roy Smith]

This spring, my club bought a 1973 200 HP Arrow with about 500 hours on
the engine. Shortly after we bought it, we had to replace several
cylinders and one piston (I'm not sure of the details of why they needed
to be replaced).

The oil pressure always indicates at the low end of the green arc
(almost into the yellow) and the oil temperature is always at the high
end, usually just barely below red line. We keep the oil level between
6 and 7 quarts, and use about a quart every 3 or 4 hours of operation.
If it ever gets below 6 quarts, it runs even hotter.

The maintenance guys say there's nothing wrong, insisting that as long
as the gauges are in the green arcs, there's nothing to worry about. In
my mind, being constantly just shy of redline, even if it's still in the
green arc, can't be a good thing. Should I be concerned?

We've got a 180 HP Arrow which always operated with the oil pressure and
temperature needles right in the middle of the green arcs. Do the 200
HP models just normally run hotter?

[NW_PILOT]

"Roy Smith" > wrote in message
...
> This spring, my club bought a 1973 200 HP Arrow with about 500 hours on
> the engine. Shortly after we bought it, we had to replace several
> cylinders and one piston (I'm not sure of the details of why they needed
> to be replaced).
>
> The oil pressure always indicates at the low end of the green arc
> (almost into the yellow) and the oil temperature is always at the high
> end, usually just barely below red line. We keep the oil level between
> 6 and 7 quarts, and use about a quart every 3 or 4 hours of operation.
> If it ever gets below 6 quarts, it runs even hotter.
>
> The maintenance guys say there's nothing wrong, insisting that as long
> as the gauges are in the green arcs, there's nothing to worry about. In
> my mind, being constantly just shy of redline, even if it's still in the
> green arc, can't be a good thing. Should I be concerned?
>
> We've got a 180 HP Arrow which always operated with the oil pressure and
> temperature needles right in the middle of the green arcs. Do the 200
> HP models just normally run hotter?


Ohh yes I would be very concerned. Sounds Like its the bottom end is giving
the problems. If I did my run up and got the readings you were getting I'd
taxi it back to parking and park it until it was fixed.

[Orval Fairbairn]

In article >,
"NW_PILOT" > wrote:

> "Roy Smith" > wrote in message
> ...
> > This spring, my club bought a 1973 200 HP Arrow with about 500 hours on
> > the engine. Shortly after we bought it, we had to replace several
> > cylinders and one piston (I'm not sure of the details of why they needed
> > to be replaced).
> >
> > The oil pressure always indicates at the low end of the green arc
> > (almost into the yellow) and the oil temperature is always at the high
> > end, usually just barely below red line. We keep the oil level between
> > 6 and 7 quarts, and use about a quart every 3 or 4 hours of operation.
> > If it ever gets below 6 quarts, it runs even hotter.
> >
> > The maintenance guys say there's nothing wrong, insisting that as long
> > as the gauges are in the green arcs, there's nothing to worry about. In
> > my mind, being constantly just shy of redline, even if it's still in the
> > green arc, can't be a good thing. Should I be concerned?
> >
> > We've got a 180 HP Arrow which always operated with the oil pressure and
> > temperature needles right in the middle of the green arcs. Do the 200
> > HP models just normally run hotter?
>
>
> Ohh yes I would be very concerned. Sounds Like its the bottom end is giving
> the problems. If I did my run up and got the readings you were getting I'd
> taxi it back to parking and park it until it was fixed.


It also sounds as if the baffle seals aren't doing their job. Any gap in
the baffling means that the air tat flows through the gap isn't helping
to cool the engine.

[Craig]

Roy Smith > wrote in message >...

> The oil pressure always indicates at the low end of the green arc
> (almost into the yellow) and the oil temperature is always at the high
> end, usually just barely below red line. We keep the oil level between
> 6 and 7 quarts, and use about a quart every 3 or 4 hours of operation.
> If it ever gets below 6 quarts, it runs even hotter.
>
> The maintenance guys say there's nothing wrong, insisting that as long
> as the gauges are in the green arcs, there's nothing to worry about. In
> my mind, being constantly just shy of redline, even if it's still in the
> green arc, can't be a good thing. Should I be concerned?
>


Get the mechanic to bypass the panel oil pressure gauge and use an
external one and do a complete run-up and see what the oil pressure is
doing. If it shows something different, then you might have a
gauge/sender problem. If it indicates the same. then I'd pull an oil
sample and have it run and then pull another sample in 5-10 hours and
make a comparison. Any thing starting to go wrong or on the way out
will show a shift in the sample.

An engine that is always floating around at the junction of the green
and yellow arc would worry me.

[Kyle Boatright]

"Roy Smith" > wrote in message
...
> This spring, my club bought a 1973 200 HP Arrow with about 500 hours on
> the engine. Shortly after we bought it, we had to replace several
> cylinders and one piston (I'm not sure of the details of why they needed
> to be replaced).
>
> The oil pressure always indicates at the low end of the green arc
> (almost into the yellow) and the oil temperature is always at the high
> end, usually just barely below red line. We keep the oil level between
> 6 and 7 quarts, and use about a quart every 3 or 4 hours of operation.
> If it ever gets below 6 quarts, it runs even hotter.
>
> The maintenance guys say there's nothing wrong, insisting that as long
> as the gauges are in the green arcs, there's nothing to worry about. In
> my mind, being constantly just shy of redline, even if it's still in the
> green arc, can't be a good thing. Should I be concerned?
>
> We've got a 180 HP Arrow which always operated with the oil pressure and
> temperature needles right in the middle of the green arcs. Do the 200
> HP models just normally run hotter?

When was the last time the oil cooler was serviced? They do corrode
internally and/or fill up with gunk over the years. Also, the fins get bent
or filled with bug carcasses. Maybe a clean-up, boil-out, or replacement is
due. Worst case, a new oil cooler is *only* $500 or so, plus installation.

Someone else mentioned to check your baffles. Replace any worn gap seal,
patch cracks, and fill any remaining gaps with RTV. Good idea and doesn't
cost much at all.

Nobody (yet) has mentioned that your mechanic may be able to adjust your oil
pressure by adjusting the setting on the oil pressure relief valve. Once
the cowl is off, this can be done in about 15 minutes. It is possible that
the setting is already at the highest adjustment possible, but you won't
know without looking.

KB

[Roy Smith]

In article
>,
Orval Fairbairn > wrote:

> It also sounds as if the baffle seals aren't doing their job. Any gap in
> the baffling means that the air tat flows through the gap isn't helping
> to cool the engine.

That would account for the high temperature, but not (I think) the low
pressure.

[Matt Whiting]

Roy Smith wrote:

> In article
> >,
> Orval Fairbairn > wrote:
>
>
>>It also sounds as if the baffle seals aren't doing their job. Any gap in
>>the baffling means that the air tat flows through the gap isn't helping
>>to cool the engine.
>
>
> That would account for the high temperature, but not (I think) the low
> pressure.

Oil becomes less viscous as temperature increases so hotter oil will
result in lower oil pressure.


Matt

[Paul Sengupta]

"Roy Smith" > wrote in message
...
> This spring, my club bought a 1973 200 HP Arrow
> The oil pressure always indicates at the low end of the green arc

I had low oil pressure on my Bulldog (200hp Lycoming IO-360-A1B6).
My mechanic adjusted the relief valve and now it's ok. He said that's all
that was wrong.

Paul

[Mike Rapoport]

I would check the guages first.

Mike
MU-2

"Roy Smith" > wrote in message
...
> This spring, my club bought a 1973 200 HP Arrow with about 500 hours on
> the engine. Shortly after we bought it, we had to replace several
> cylinders and one piston (I'm not sure of the details of why they needed
> to be replaced).
>
> The oil pressure always indicates at the low end of the green arc
> (almost into the yellow) and the oil temperature is always at the high
> end, usually just barely below red line. We keep the oil level between
> 6 and 7 quarts, and use about a quart every 3 or 4 hours of operation.
> If it ever gets below 6 quarts, it runs even hotter.
>
> The maintenance guys say there's nothing wrong, insisting that as long
> as the gauges are in the green arcs, there's nothing to worry about. In
> my mind, being constantly just shy of redline, even if it's still in the
> green arc, can't be a good thing. Should I be concerned?
>
> We've got a 180 HP Arrow which always operated with the oil pressure and
> temperature needles right in the middle of the green arcs. Do the 200
> HP models just normally run hotter?

[Mike Noel]

The first thing I would do is pull the oil cooler bypass valve (Vernatherm)
and look at the seat. If the seat's surface indicates uneven closing
against the corresponding surface in the oil filter adapter, the valve
should be replaced and either the seat in the adapter should be resurfaced
or you should get a new oil filter adapter.

I had similar problems in a Lycoming O-360-A4A and this fix made a big
difference.

--
Regards,
Mike

http://mywebpage.netscape.com/amountainaero/fspic1.html
"Roy Smith" > wrote in message
...
> This spring, my club bought a 1973 200 HP Arrow with about 500 hours on
> the engine. Shortly after we bought it, we had to replace several
> cylinders and one piston (I'm not sure of the details of why they needed
> to be replaced).
>
> The oil pressure always indicates at the low end of the green arc
> (almost into the yellow) and the oil temperature is always at the high
> end, usually just barely below red line. We keep the oil level between
> 6 and 7 quarts, and use about a quart every 3 or 4 hours of operation.
> If it ever gets below 6 quarts, it runs even hotter.
>
> The maintenance guys say there's nothing wrong, insisting that as long
> as the gauges are in the green arcs, there's nothing to worry about. In
> my mind, being constantly just shy of redline, even if it's still in the
> green arc, can't be a good thing. Should I be concerned?
>
> We've got a 180 HP Arrow which always operated with the oil pressure and
> temperature needles right in the middle of the green arcs. Do the 200
> HP models just normally run hotter?