Instead of guessing, go to you well stocked Auto Parts Store and buy an oil pressure gauge kit. Not too much money and it's a good diagnostic tool. Remove the Oil Pressure sender and install the line for the kit and then see what the pressure is. Then you'll know if it is, indeed, the pump or some other item in the system. When done with this problem, put the kit in your trouble box for another time or install it and you'll be able to actually see the pressure instead of an analog "about this much" reading. Ray On Sep 25, 2011, at 7:51 PM, C Bilter wrote: Hi Bob, I agree with the folks who suggest looking at the sending unit first and then the gauge or the gauge voltage limiter. At hot idle your engine actually doesn't require a lot of oil pressure, but the gauge should not read "zero." If you decide to change out the oil pump, here is an article I recently wrote that is posted in the tech department on the club website that might be helpful: http://www.chrysler300club.com/tech/joil/oilp.html 300ly, Carl Bilter Current 300J and former G owner _____ From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Bob Jasinski Sent: Sunday, September 25, 2011 5:40 PM To: mgoodknight@xxxxxxxx Cc: 'Chrysler 300 List' Subject: RE: [Chrysler300] 413 oll pump I have no problem with oil pressure above idle speed whether the engine is hot or cold, the driving pressure is just fine, at least 1/2 to 2/3rds pressure on panel gauge. The drop in pressure only happens after an extended run, on a hot day, like when you come off the freeway and are at a light in gear, or dead stopped on the freeway in traffic, with the engine idle around 650-750 RPMs. The pressure literally drops to a zero reading on the gauge, and that is what concerns me, especially if you are stopped in traffic for long periods.. As I sit there looking at no pressure I envision the bearings running with no lubrication and worry about it. This has happened with two different brands and weight of oil, 10-30W and 10-40W, but did not happen with the 20-50W. I also am running the prescribed amount of Redline zinc additive, which I believe tends to thin the oil a bit. Maybe I should try a straight weight oil, but I think the problem could just get worse with a straight 30W, as the viscosity won't increase with temperature as do the multiweight oils. As I see it, the needle should at least be at the bottom of the pressure indication, even at idle, not at zero. Bob From: mgoodknight@xxxxxxxx <mailto:mgoodknight%40juno.com> [mailto:mgoodknight@xxxxxxxx <mailto:mgoodknight%40juno.com> ] Sent: Sunday, September 25, 2011 2:22 PM To: rpjasin@xxxxxxxxxxx <mailto:rpjasin%40pacbell.net> Subject: RE: [Chrysler300] 413 oll pump Bob, I should have added: the fact that you have lower oil pressure at idle with 10w-40 does not mean that you have lower oil pressure at speed. It is quite likely that your pressure is still being limited to around 60-70psi by the pressure relief system. Supplying too much pressure to the bearings can cause erosion of the soft materials that make the good bearing surfaces on the bearing inserts. In race conditions that erosion risk is tolerated because of frequent bearing changes. Marshall Goodknight, retired engine failure analyst and long time engine technician with Mechanical Engineering education ---------- Original Message ---------- From: "Bob Jasinski" <rpjasin@xxxxxxxxxxx <mailto:rpjasin%40pacbell.net> > To: "'Bill Huff'" <czbill@xxxxxxxxxx <mailto:czbill%40cfl.rr.com> >, <chrysler300@xxxxxxxxxxxxxxx <mailto:chrysler300%40yahoogroups.com> > Subject: RE: [Chrysler300] 413 oll pump Date: Sun, 25 Sep 2011 13:24:26 -0700 Because a year ago I changed the oil to 20-50W and the problem went away. Last week I changed the oil back to 10-40W and the problem came back, so I figure it is the pump, but I am open to suggestions as to other causes. Bob J From: Chrysler300@xxxxxxxxxxxxxxx <mailto:Chrysler300%40yahoogroups.com> <mailto:Chrysler300%40yahoogroups.com> [mailto:Chrysler300@xxxxxxxxxxxxxxx <mailto:Chrysler300%40yahoogroups.com> <mailto:Chrysler300%40yahoogroups.com> ] On Behalf Of Bill Huff Sent: Sunday, September 25, 2011 1:05 PM To: Bob Jasinski; chrysler300@xxxxxxxxxxxxxxx <mailto:chrysler300%40yahoogroups.com> <mailto:chrysler300%40yahoogroups.com> Subject: Re: [Chrysler300] 413 oll pump What made you settle on the oil pump as the reason for low oil pressure? Bill Huff 3:27 PM, Bob Jasinski wrote: > > >I think it's time to replace the oil pump in my 300G. I'm noticing pressure >is dropping to a very low level on a hot day after a long drive while in >gear and idling (went to the Ironstone Concours in Murphys yesterday) > >I looked at Rock Auto, and they list 3 different oil pumps all from the same >manufacturer (Sealed Power) and one is standard, the second is >"High-Volume", the 3rd is "High Pressure". Prices are only $10 more as you >go up. > >What gives? Why should I go with a standard pump if the other two are so >close in price? Is there a problem going with a non-stock pump? Could it >blow out seals in an older rebuilt engine? Those in the know please share >your knowledge on this. > >Thanks! > >Bob J > >[Non-text portions of this message have been removed] > > [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] __________________________________________________________ <http://thirdpartyoffers.juno.com/TGL3132/4e7f9b7c236a473fdcfst04duc> Penny Stock Jumping 3000% Sign up to the #1 voted penny stock newsletter for free today! <http://thirdpartyoffers.juno.com/TGL3132/4e7f9b7c236a473fdcfst04duc> AwesomePennyStocks.com [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! 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