400 Oil Pressure question
#357030
06/24/09 07:29 PM
06/24/09 07:29 PM
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Joined: Jan 2003
Posts: 1,037
Texas, Dallas
G_T
OP
super stock
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OP
super stock
Joined: Jan 2003
Posts: 1,037
Texas, Dallas
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1977 400, about 105K miles on it. Engine runs fine, no knocks, weird noises, etc. Mechanical oil gage.
2 months ago, it had 65-70psi cold, and ~30psi hot, ~10psi idle.
It has slowly dropped since. Did the usual oil changes (10W-40) and oil filter (puralator).
Now it is ~40psi cold, and ~5-10psi hot, 0psi at idle.
The top end was rebuilt about a year ago (head work, cam, manifold, etc.).
I'm not sure if the engine is just worn, or if a replacement oil pump is in order.
Other than leaking oil, it doesn't seem to burn/smoke.
Any harm with installing a high vol pump?
Other suggestions?
1970 Charger - V10, 6spd, Alterkation, Street Lynx 4 Link, Moser Dana 60, Wilwood 14" disks, Forgeline 18" Wheels (Rear:335's), ISIS Multiplexing Wiring http://www.v10mopar.com
2012 Charger SRT8
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Re: 400 Oil Pressure question
[Re: dOrk !]
#357033
06/24/09 07:48 PM
06/24/09 07:48 PM
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Joined: Jan 2003
Posts: 1,037
Texas, Dallas
G_T
OP
super stock
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OP
super stock
Joined: Jan 2003
Posts: 1,037
Texas, Dallas
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last oil change was 2K ago. Pan was pulled the same time we did the top end to change gaskets and rear main seal. Nothing in the pan at that time (Actually I was surprised as it had the stock nylon timing set which we replaced with a dbl roller set at the time).
Engine was very clean inside - no crud/etc.
I guess a $65 high vol pump isn't a bad investment - very easy to change. Just seems odd that a pump would slowly go away like that over a 6 month period of time...
1970 Charger - V10, 6spd, Alterkation, Street Lynx 4 Link, Moser Dana 60, Wilwood 14" disks, Forgeline 18" Wheels (Rear:335's), ISIS Multiplexing Wiring http://www.v10mopar.com
2012 Charger SRT8
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Re: 400 Oil Pressure question
[Re: G_T]
#357034
06/24/09 07:52 PM
06/24/09 07:52 PM
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Joined: Jul 2008
Posts: 30,424
Florida STAYcation
dOrk !
The village idiot's idiot
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The village idiot's idiot
Joined: Jul 2008
Posts: 30,424
Florida STAYcation
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Quote:
Just seems odd that a pump would slowly go away like that over a 6 month period of time...
THAT is very odd ...I would put another gauge on it to double-check the psi.
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Re: 400 Oil Pressure question
[Re: dOrk !]
#357035
06/24/09 07:56 PM
06/24/09 07:56 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Pump is fine
drive it until it pukes
Yea ..maybe the cam bearings have gone away
maybe maybe maybe this maybe that--drive it! Have fun! when it quits THEN fix it--save that oil pump $$ for a tank of gas--
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Re: 400 Oil Pressure question
[Re: dOrk !]
#357036
06/24/09 07:57 PM
06/24/09 07:57 PM
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Joined: Jan 2005
Posts: 2,179
S.E. Conn
Hoof Hearted
top fuel
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top fuel
Joined: Jan 2005
Posts: 2,179
S.E. Conn
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Free advice from experience, cheap enough to do.
1) Replace oil pump with a Melling Hi-VOLUME (not pressure)
2) go with at least a 10/40 (I like Rotella 15/40)
3) Use a Napa Gold oil filter
4) consider changing the oil pump Input Shaft to a Mopar Perf. HARDENED Shaft.
2005 300C Hemi
2014 Ram ProMaster 2500
I Rekey, Repin old Chrysler locks and cut keys by code
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Re: 400 Oil Pressure question
[Re: ]
#357037
06/24/09 07:59 PM
06/24/09 07:59 PM
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Joined: Jan 2008
Posts: 3,886
Lost and Spaced
bboogieart
master
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master
Joined: Jan 2008
Posts: 3,886
Lost and Spaced
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Quote:
Pump is fine
drive it until it pukes
Yea ..maybe the cam bearings have gone away
maybe maybe maybe this maybe that--drive it! Have fun! when it quits THEN fix it--save that oil pump $$ for a tank of gas--
and carry plenty of freinds to push when it fails.
I say check with a mechanical guage and make sure of your pressure befor anything else. If your bearings are wiped out, a new pump wont do anything. you could try thicker oil and see what that does for you.
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Re: 400 Oil Pressure question
[Re: Hoof Hearted]
#357038
06/24/09 10:23 PM
06/24/09 10:23 PM
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Joined: Jan 2003
Posts: 1,037
Texas, Dallas
G_T
OP
super stock
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OP
super stock
Joined: Jan 2003
Posts: 1,037
Texas, Dallas
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Quote:
Free advice from experience, cheap enough to do.
1) Replace oil pump with a Melling Hi-VOLUME (not pressure)
2) go with at least a 10/40 (I like Rotella 15/40)
3) Use a Napa Gold oil filter
4) consider changing the oil pump Input Shaft to a Mopar Perf. HARDENED Shaft.
Thanks Hoof... that is what I was planning. I really don't think it's the oil pressure gage...but, I can get another one to validate.
Worse case - if it blows, I have a spare 400 in the garage 
1970 Charger - V10, 6spd, Alterkation, Street Lynx 4 Link, Moser Dana 60, Wilwood 14" disks, Forgeline 18" Wheels (Rear:335's), ISIS Multiplexing Wiring http://www.v10mopar.com
2012 Charger SRT8
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Re: 400 Oil Pressure question
[Re: G_T]
#357039
06/24/09 10:27 PM
06/24/09 10:27 PM
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Joined: Dec 2003
Posts: 5,314
Carstairs, Alberta, Canada
dave571
master
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master
Joined: Dec 2003
Posts: 5,314
Carstairs, Alberta, Canada
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Quote:
Any harm with installing a high vol pump?
Very good plan. This is actually what a hi volume oil pump was designed for. To restore pressure in engines with bigger clearance.
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Re: 400 Oil Pressure question
[Re: G_T]
#357041
06/24/09 10:29 PM
06/24/09 10:29 PM
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Joined: Jan 2003
Posts: 1,037
Texas, Dallas
G_T
OP
super stock
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OP
super stock
Joined: Jan 2003
Posts: 1,037
Texas, Dallas
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I thought the shaft on a big-block is integral to the distributor cam gear? I thought you only went with the hardened (bronze gear?) if you had a roller cam? Or am I off?
1970 Charger - V10, 6spd, Alterkation, Street Lynx 4 Link, Moser Dana 60, Wilwood 14" disks, Forgeline 18" Wheels (Rear:335's), ISIS Multiplexing Wiring http://www.v10mopar.com
2012 Charger SRT8
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Re: 400 Oil Pressure question
[Re: stumpy]
#357043
06/24/09 10:33 PM
06/24/09 10:33 PM
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Joined: Jan 2003
Posts: 1,037
Texas, Dallas
G_T
OP
super stock
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OP
super stock
Joined: Jan 2003
Posts: 1,037
Texas, Dallas
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No reason to at the time (12 months ago). Everything was fine. Motor ran strong, zero issues other than the leaking rear main seal. Engine only had ~70K on it at the time.
1970 Charger - V10, 6spd, Alterkation, Street Lynx 4 Link, Moser Dana 60, Wilwood 14" disks, Forgeline 18" Wheels (Rear:335's), ISIS Multiplexing Wiring http://www.v10mopar.com
2012 Charger SRT8
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Re: 400 Oil Pressure question
[Re: G_T]
#357045
06/24/09 11:29 PM
06/24/09 11:29 PM
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Joined: Jan 2005
Posts: 2,179
S.E. Conn
Hoof Hearted
top fuel
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top fuel
Joined: Jan 2005
Posts: 2,179
S.E. Conn
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Quote: "I thought the shaft on a big-block is integral to the distributor cam gear? I thought you only went with the hardened (bronze gear?) if you had a roller cam? Or am I off?"
Yeah, you're a little off; Mopar Perf. makes an input shaft with a Forged(?) HARDENED End. With the heavier oil and volume of flow comes more of a chance you'll round off the tip, as we've all done with allen wrenches ...
The gear end stays the same.
2005 300C Hemi
2014 Ram ProMaster 2500
I Rekey, Repin old Chrysler locks and cut keys by code
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*UPDATE* 400 Oil Pressure question
[Re: Hoof Hearted]
#357046
07/14/09 01:28 AM
07/14/09 01:28 AM
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Joined: Jan 2003
Posts: 1,037
Texas, Dallas
G_T
OP
super stock
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OP
super stock
Joined: Jan 2003
Posts: 1,037
Texas, Dallas
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Well the bandaid seemed to work. Swapped out the oil pump for a high vol unit, checked gage, new filter/oil & shaft as stated above. Primed it and fired it up. 75psi cold 25psi hot idle @ 195 degrees and 700 rpm I'm sure it's a matter of time before a rebuild, but this seems to have cured it for a bit. Just a waiting game - so I can have some fun for a while. I'll post again if/when a tap or knock develops  Btw, removing the oil pump shaft for priming/replacement was real fun (NOT). Did it with the manifold on - made a little tool to grab the gear and pull it out the distributor hole.
1970 Charger - V10, 6spd, Alterkation, Street Lynx 4 Link, Moser Dana 60, Wilwood 14" disks, Forgeline 18" Wheels (Rear:335's), ISIS Multiplexing Wiring http://www.v10mopar.com
2012 Charger SRT8
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Re: 400 Oil Pressure question
[Re: RapidRobert]
#357048
07/14/09 12:25 PM
07/14/09 12:25 PM
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Joined: Nov 2006
Posts: 2,255
IL
furious70
top fuel
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top fuel
Joined: Nov 2006
Posts: 2,255
IL
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oil psi dropped out of the blue after racing 2 yrs ago in the 383 in my Fury, put a new pump on and it went back to normal and has been fine since. I did not tear down the old pump to diagnose, was happy it was fixed.
70 Sport Fury
68 Charger
69 Coronet
72 RR
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