Oil pump going bad?

[RECHRGD]

Last cruise of the year yesterday.  When pulling into the storage area I noticed more valve train noise than usual.  My oil pressure was reading low, but it has been pretty low since replacing a leaky sending unit last spring with one from NAPA.  I've just been living with the bad sending unit this season and plan to replace it now.  With the old unit the engine always maintained between 40 and 70 lbs.  I trailered the car home today and played with it for awhile.  Oil level was a little low, so I added a quart of Valvoline 20/50 racing oil.  The noise didn't get any better.  At idle I determined that the gauge was reading slightly lower than it had been during the summer drives.  While in park I slowly raised the rpms to see if the pressure would raise any.  Guess what!  It actually went down to about 2/3 of what it was reading at idle when at 3500 rpm.  The oil pump was replaced probably about twelve years ago.  The short block has about 45k miles on it with trw forged Pistons.  The cam, heads and valve train probably about 10k.  The rockers are crane gold adjustable units and haven't been touched for about 9k miles.  The first thing I need to do is get a good sending unit and go from there, but I'm thinking that the pump is toast....

[cdr]

1st go get a manual gauge & check the pressure.

[Dmichels]

The oil pump is rarely the problem. As above check with a mechanical gauge
Dave

[RECHRGD]

Mechanical pump is on its way from Amazon.......

[RECHRGD]

Gauge.....

[cdr]

this is the sender that reads proper if everything else is working correct

http://www.ebay.com/itm/Mopar-Oil-Pressure-Gauge-Sending-Unit-340-383-440-Hemi-OEM-TYPE-Plymouth-Dodge-/221917435520?hash=item33ab4f5680

[RECHRGD]

this is the sender that reads proper if everything else is working correct

http://www.ebay.com/itm/Mopar-Oil-Pressure-Gauge-Sending-Unit-340-383-440-Hemi-OEM-TYPE-Plymouth-Dodge-/221917435520?hash=item33ab4f5680

[RECHRGD]

OK, the sun finally came out today and gave me the incentive to go check things out with the mechanical gauge.  The gauge is a 0 to 300lb. Chinese unit I got from Amazon, so maybe the lower range readings are not perfectly accurate.  It's been parked since last October.  At start up it showed 75lbs. At around 1200 rpm.  At idle after warm up it dropped to about 65 and would go over 75 at about 2500rpm.  I let it run about 25 minutes and the abnormal valve train noise never returned.  Same oil and filter as when parked four months ago.  If it weren't for the noisy valve train when parked, I would just chalk it up to the sending unit going nuts.  I've got a new unit to install and hopefully that will read more in the range the I'm used to.  Any thoughts?  The wife said she "willed" it to fix itself.

[cdr]

re-reading the original post, the oil pump check valve could have gotten stuck open, & now closed, i would pull the spring & valve & inspect it for galling.

[RECHRGD]

re-reading the original post, the oil pump check valve could have gotten stuck open, & now closed, i would pull the spring & valve & inspect it for galling.

Should do...  But tempted to just forge ahead and go cruising....

[A383Wing]

and if it sticks again, you may end up with zero pressure and an engine that will be toast

[c00nhunterjoe]

1: Does the factory gauge match the readings you show on the mech gauge?
2: if answer to 1 is yes, you had no oil pressure in oct. Probably the pump.
3: if you have 65 psi at hot idle and passing 75 and climbing at cruise rpm, 50wt is too thick. Try a 40wt.

[ws23rt]

re-reading the original post, the oil pump check valve could have gotten stuck open, & now closed, i would pull the spring & valve & inspect it for galling.

Should do...  But tempted to just forge ahead and go cruising....

I agree with CDR about a possible explanation for your trouble/question. I also think their is little risk that you will take by just driving and paying close attention to your new mechanical gauge as a back up (and addition)to help identify any issue with the stock gauge. If all is good and the original problem does not come back this is a good thing.

I'm sure we all have had symptoms of trouble that come and go and that makes us wonder why?  That is how stuff fails. Sometimes bit by bit. And sometimes all at once. ---If all is good forward from here their is no practical direction to answer the original question. It has to fail again to identify the problem.

As we age we see and feel this with our selves ----One thing that is true is that what precedes failure is full functioning. ---

Don't not drive your car just because you think it might/will break.

[RECHRGD]

Well, I'll be changing the oil and filter before doing any cruising this spring.  I may dig into the pump at that time or just replace it for peace of mind............

[cdr]

if you replace the pump, be sure & take the new pump completely apart to clean it out & the lube it up , & after install prime it up.

[RECHRGD]

if you replace the pump, be sure & take the new pump completely apart to clean it out & the lube it up , & after install prime it up.

[Back N Black]

I has issues with three sending units(Low reading). I gave up and used a mechanical gauge and it reads 40 degrees at idle and 70 at higher RPM. So i think your good.

[jlatessa]

Ordered the sending unit from Rick Ehrenburg, my NAPA sender hardly registers
but the mechanical in the other galley port shows good pressure.
Now, does anyone have a source for the push-on type terminal his senders require?

Thanks, Joe