I would put a mechanical gauge that is known to be good on the engine first. If it confirms the very low oil pressure then check further. You could also pull a valve cover to see if oil is circulating to the valve train at hot idle. The pump is not difficult to remove and check. If it is not scored and the rotor is within the specified clearance measuremenst to the housing (see FSM), the pump is good. Check the the spring loaded pressure valve for free operation, replace the spring if needed. It's been my experience that very low pressure at idle is due to excessive bearing clearance. I did have a big block Barracuda that had low oil pressure all the time and no oil pressure at idle. Turned out to a clogged tube to the mechanical gauge. I don't think a high volume pump has a place in a stock engine. The bypass will open at the proper pressure so you won't really gain anything at speed and you shouldn't need the extra flow at idle with a good engine. If you do need the extra flow, much better to fix the problem than to put a band aid on it. Good Luck. Bill Huff M, Bob Jasinski wrote: > > >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: ><mailto:Chrysler300%40yahoogroups.com>Chrysler300@xxxxxxxxxxxxxxx >[mailto:Chrysler300@xxxxxxxxxxxxxxx] On >Behalf Of Bill Huff >Sent: Sunday, September 25, 2011 1:05 PM >To: Bob Jasinski; ><mailto:chrysler300%40yahoogroups.com>chrysler300@xxxxxxxxxxxxxxx >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] > > [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! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/