97 T&C 225000 low oil pressure at stop signs.

Mobil 1 at 5k intervals from start. Doesn't use between changes.
Crumpled oil pan at 200k, and dealt with it. At 220k, oil pressure
idiot light started flashing (and ringing) now and then while at stop
in drive. Move to neutral, flicked off. Had pan and pump replaced,
and the installed Qaker State, not the synthetic stuff I'd been using.
1000 miles later, it still does it.

Guy didn't give me an actual reading on the pressure. I'm wanting to
question the accuracy of the information reported by the idiot light.
Is there a relatively easy way to include a guage on the daskboard that
I can believe - even if it does tell me that yes, your engine has
finally worn out.

And if it's genuinely low, is it just going to throw a rod, or is it
going to give me some further notice before truly leaving me stranded?

BTW - I added an STP type treatment thinking I'd thicken the brew a bit
(still has the Quaker State 10-30 in it. Seemed to helf for awhile,
but it's back. Have 5 quarts of 20-50 on hand to use next oil change
(tomorrow? Going on a trip if it'll still do it). As an old Triumph
Bonneville owner, I know a little about thicker oil. As it relates to
Bonnevilles. Am I making things worse with 20-50?

This is the AWD model, 3.8 V6. Runs like a jewel in all other regards.
Weeps a bit about the rocker box gaskets.

Would appreciate any ideas, as am hoping to make a trip overf Christmas
in it. Even got fresh wiper blades.

Clayton

 

First clean the pressure sensor plug with contact cleaner. Was the pump
actually replaced or just the bent pick-up tube? Did you actually request
to see the parts?

Take out the oil pressure sending unit, replace it with a T-fitting
reinstall sending unit hook up mechanical gauge it is simple.

BIG BIG MISTAKE!!! on 20w50, use the correct vescosity in your ownres
manual. A heavier weight oil WILL cause premature oil pump failure, along
with bearing and ring failure your engine was not designed to run on that
viscosity.

Coasty

 

Sure, get a mechanical oil pressure gauge from your FLAPS and use a
tee-fitting wherever the sender screws in (probably on the head
somewhere, but may be on the oil filter mount.) you'll need to find a
hole in the firewall through which to pass a tiny nylon piece of tube,
but that's it. also will need to find the dash lights circuit if you
want to read the gauge at night.

You should read *some* pressure at idle, at least 7-8 PSI, and at least
10 PSI/1000 RPM when driving. (NB: these are generic recommendations.
The actual repair manual for your vehicle may have slightly different
specs) If you lose pressure by more than a couple PSI when you stand on
the gas, but it immediately comes back when you lift off, that's a sign
of excessive rod and main bearing clearances and your next step should
be to drop the pan again and roll some new shells in there. If nothing
else loose rod bearings can confuse your knock sensor and cause
driveability problems.

Thicker oil will definitely "help" if the only problem you have is low
oil pressure (i.e. there's no rattling or knocking.) I know my Porsche
looks like the bearings are about shot by the gauge when running Mobil 1
0W40 but after switching to Rotella T 5W40 - which isn't even a
different grade, just towards the heavier end of the 40 weight spec than
the Mobil - it looks a lot better.

Is it possible that you have a bad oil pressure sender? IME when
they've failed, they tend to fail by not driving the light (won't light
up with key on/engine off) but I have heard tell of them failing the
other way. The only way you will know is to hook up a gauge and see
what it says.

good luck

nate

(doesn't drive cars without oil pressure gauges, except for the company
heaver.)

 

I would suspect the sensor. Why did you switch from Mobil 1 to Quaker
State? Not a good move.


Matt

 

At 220+K miles, I'd suspect the oil pressure sender switch may be worn out.
It is fairly inexpensive and easy to replace, so I'd try that first. While
you have the sender out, you can hook up a regular mechanical oil pressure
diagnostic gauge and measure the actual oil pressure under idle conditions
and watch it as the engine warms up and the oil thins out.

If the new sender doesn't eliminate the flickering, then I'd suspect the oil
pump or possibly a clogged pickup, although the mechanic that removed the
pan and installed a new one should have made sure it was in good shape
before reassembling. This is why I'd suspect the sender first.

On the heavier oil, I'd personally not use the 20W-50. I'd go no higher
than 10W-30 and in winter if you are in a colder climate, I'd keep to the
recommended 5W-30.

Bob

 

Let me be the third vote for a bad pressure switch. Replace it and your
problem will go away. It would be a good idea, as others have
suggested, to actually measure the pressure for peace of mind.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

A bad connection is not his problem. If it were, the light would not
come on regardless of the oil pressure.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Thanks for the insight, everybody.

The pump and pan were replaced. As to old parts, no I didn't see them.
But, I'm pretty sure they put in a new one (I was doing some computer
work for the dealer, they offered discount on labor to 'employees', and
they were doing me right). The actual mechanic, on the other hand, was
too busy to move to the next task to discuss much. The service manager
said hey, he's good, he's fast, and he's not real talkative.

They didn't remember my comment on Mobil 1, and didn't recognize what
the case of it was doing on the floorboard of the passenger side. Oh,
well. So that's why the Quaker State.

I'm not real mechanical anymore since losing the use of one arm in a
little motorcycle adventure. But I'm going to have to get someone to
help me with a guage. As someone said earlier in the thread, all of
his vehicles have guages.

I must say, I've already done an oil change with some mineral based
20W-50. Perhaps the reason I've gottten so many trouble free miles is
the Mobil 1, but I've had more than a few gearheads tell me that at 5k
changes I'm just spending extra bucks. At a quarter of a million
miles, I've sort of gotten my use out of the thing, and I shan't expect
another quarter even if I use synthetic.

As to dropping the pan and rolling some new shells in - yikes! I
haven't seen the crankshaft of anything except my model airplane
engines in years. I just can't get that deep into things anymore.
I've been 12 years with one arm dangling, and most folks are surprised
I even change my own oil still. With the quality of service this T&C
has given me, I'll buy another when the day comes. What a bullet proof
vehicle. 160k on the 1st transmission, one replaced alternator,
replaced brake disks once, and some a/c work (new evaporator/condenser
or whatever it is that looks like a radiator under the dash), I simply
can't complain. Even the driveshaft to the AWD is original, though the
boot has been torn for a few years. Original shocks/struts even
(wheels still don't hit the fenders). I live on a dirt road and it
ain't like it'll ever drive like a new vehicle again. Alas, it has a
nice stereo.

Anyhow, you folks have confirmed that it should be easy enough to
install a gauge. And that a dirty or faulty sender could be replaced
at the same time. As to replacing the oil with 20W-50 and it not being
recommended, I'll hope I haven't signed my death wish. We'll know if I
throw a rod on my little trip. I'm under the gun, and had already made
an executive decision prior to getting back to my computer. I'll
report back in after I go hopping across the country to visit my crazy
brother.

Again, thanks everybody for the insight.

Clayton

 

You may well be spending extra bucks, I won't argue that, but I live in
a cold climate and the much better cold temperature cranking makes the
Mobil 1 worth it for me even with 5K changes. My 96 GV has 178,000
miles on it now so I just lenthened my change intervals to 10,000 miles
rather than switching to dino oil. I cut my costs in half that way and
since I no longer care if this van lasts much longer, I see nothing too
lose. However, I've been using the 10,000 mile intervals since 150K and
so far, I can't tell any difference! The oil is a little blacker at 10K
than 5K, but barely enough to tell the difference. The old 3.3 uses
about a quart every 1500 miles, so it gets 6 or so fresh quarts between
every change anyway. It has used this much oil since I bought it with
33K on it, so nothing has degraded oil consumption-wise in nearly 150K
miles. And the engine is as quiet at idle or WOT as it has ever been.

Yes, installing a gauge is the best way to confirm your problem. I'm
still betting on a bad pressure sensor, but it could be something more
serious. The gauge will help you know.


Matt

 

I started using Mobil 1 back in the days of my Moto Guzzi 650. The
racing guys at Daytona swore it was worth another 5 mph or half a
second or whatever. And my 93 Dakota did 175k with no trouble (guy I
sold it to for 3/4 of what I paid for it said it was the nicest vehicle
he'd ever owned). It never used oil, and the T&C still doesn't. I
like the stuff.

That said, the spousal unit's 2001 PT Cruiser has used a little since
day one. 75k, and no worse than at the beginning, but I add 1/2 qt
every 1500 miles or so. Probably twice between changes (5k) anyhow.

A gauge. And a sending unit. I'll hope one of my motorhead friends
can help me out.