Random 5 - 10psi oil pressure drop - Ford Muscle Forums : Ford Muscle Cars Tech Forum
Reply
 
LinkBack Thread Tools
post #1 of 59 (permalink) Old 04-17-2009, 03:39 AM Thread Starter
Registered User
 
Join Date: Oct 2007
Posts: 141
Random 5 - 10psi oil pressure drop

Hey gang, what would cause oil pressure to drop 5-10 psi at random. Sometimes it does it other times it doesn't. Might be once in a short trip or it may be 5 times in a short trip. It kind of makes me worried. I took off the fram oil filter and put a motorcraft on after first oil change after being ridiculed for having the orange filter LOL. It is a high volume meling pump and either a canton or milodon oil pan but I don't know how much it holds. I have 7 quarts in it now but even when I had 6 in it did it. It just started doing it yesterday at least as far as me noticing it. It will do it at any time, whether you are cruising or idling or coming to a stop. Could it be air in the gauge tubing?

Oil pressure at idle in neutral is 30 psi, in gear it is 22-25 psi. Cruising it was close to 60 psi but it seems to stay around 52-53 now.

72' F100 398W
NUTNDUN is offline  
Sponsored Links
Advertisement
 
post #2 of 59 (permalink) Old 04-17-2009, 04:02 AM
Tech Contributor Gold
 
Join Date: Dec 2004
Location: Amish Wonderland Of Central PA
Posts: 4,910
Garage
Re: Random 5 - 10psi oil pressure drop

Factory gauge? The sending units act like that when they go bad. Still, you are correct in feeling uneasy about it.

Irregardless, I suggest first testing with another gauge--preferably a mechanical one. I have one installed under the hood in order to remove all doubt.

Dennis

65' Stang Street/Strip. Dart 434W NA, Victor heads, G101A 4 Spd, 4:56 rear gear, on 93 octane pushing 3550lbs. [email protected]

Last edited by dennis111; 04-17-2009 at 04:05 AM.
dennis111 is offline  
post #3 of 59 (permalink) Old 04-17-2009, 04:14 AM Thread Starter
Registered User
 
Join Date: Oct 2007
Posts: 141
Re: Random 5 - 10psi oil pressure drop

It is an autometer pro comp liquid filled mechanical gauge. I don't know if they can go bad? Could it also be some break in lube still in the motor or shouldn't that have an affect? I am keeping an eye on it the whole time so I can shut her down just in case. When it does drop it comes right back up. I would think that if it were something wrong motor wise that it would be constant.

72' F100 398W
NUTNDUN is offline  
 
post #4 of 59 (permalink) Old 04-17-2009, 05:08 AM Thread Starter
Registered User
 
Join Date: Oct 2007
Posts: 141
Re: Random 5 - 10psi oil pressure drop

I am going to get another filter and change the oil again tonight and see if that helps aslo. I was planning on taking it for a nice drive and cruise tomorrow but I don't know if I want to until I know for sure it is going to be alright.

72' F100 398W
NUTNDUN is offline  
post #5 of 59 (permalink) Old 04-17-2009, 06:48 AM
Tech Contributor Gold
 
Join Date: Dec 2004
Location: Amish Wonderland Of Central PA
Posts: 4,910
Garage
Re: Random 5 - 10psi oil pressure drop

Yes kinked tubing will affect the gauge reading.

Hopefully you are not running a Fram oil filter.

Did you cut open the any of the old oil filters? Might try that and check for debris.

Dennis

65' Stang Street/Strip. Dart 434W NA, Victor heads, G101A 4 Spd, 4:56 rear gear, on 93 octane pushing 3550lbs. [email protected]
dennis111 is offline  
post #6 of 59 (permalink) Old 04-17-2009, 06:59 AM Thread Starter
Registered User
 
Join Date: Oct 2007
Posts: 141
Re: Random 5 - 10psi oil pressure drop

I have the fram filter I took off but didn't cut it open yet. We double checked and torqued the pick up tube. Maybe the pressure relief on the pump is acting up? I am going to double check the line because now that I think about it I did put a wire loom over it and the water temp gauge line to make it look nicer and protect it, maybe I have it bound somewhere.

The other thing I was wondering is the only time I have noticed it is when I am off the gas so I am wondering if maybe the torque converter might be letting it come more to an idle or something. It would be nice if it was consistent it would be alot easier to diagnose. It is so random and it is only a 5psi drop and it comes right back.

72' F100 398W
NUTNDUN is offline  
post #7 of 59 (permalink) Old 04-17-2009, 07:07 AM
Registered User
 
Join Date: Mar 2004
Location: Puyallup, WA
Posts: 1,788
Re: Random 5 - 10psi oil pressure drop

Fram has got to be one of worse filters out there. I either use Amsoil's EO filters or Napa Gold oil filters. They do a far better job.

347 Stroker, 10.6:1, Vic Jr, World Jr. heads (2.02/1.60 valves), Custom 780cfm ProSystems 4150 Double Pumper, XE284H cam, MSD E-Curve, 4.30 gears/31 Spline axles, Tremec TKO 5 Speed w/.83 5th gear ratio.
Spali32 is offline  
post #8 of 59 (permalink) Old 04-17-2009, 07:20 AM Thread Starter
Registered User
 
Join Date: Oct 2007
Posts: 141
Re: Random 5 - 10psi oil pressure drop

Ya the fram was only on there for about 10 mile. I had it already and just used it. It has a motorcraft on it now. I might swing by napa on the way home and get a filter.

72' F100 398W
NUTNDUN is offline  
post #9 of 59 (permalink) Old 04-17-2009, 09:18 AM
Premium Member
 
Join Date: Sep 2004
Location: Sunny Arid Desolate Port Orchard WA
Posts: 34,853
Re: Random 5 - 10psi oil pressure drop

Fram, motorcraft napa, autozone Wix..... THey ALL filter the oil, some have anti drain back some do not. None of them effect eh oil pressure like that. Ever...

Failing Gauge or Failing pressure releif valve in teh oil pump get's my vote...

Kinked hose isn't likely unless the oil pressure drops 5 lbs every time you hit a bump... no Bump no reason for hose to kink...

THat's my logic, maybe it's not logical at all...
FEandGoingBroke is offline  
post #10 of 59 (permalink) Old 04-17-2009, 09:28 AM Thread Starter
Registered User
 
Join Date: Oct 2007
Posts: 141
Re: Random 5 - 10psi oil pressure drop

I am going to change the oil and filter tonight just to rule that out and see how it does. It wouldn't surprise me if it is the gauge because of it sitting around for 3 years and chances of it getting knocked around were pretty good. I would think that if the pressure relief in the pump was taking a dump it would have done it when the motor was first started.

The motor doesn't use oil and it doesn't even have more then maybe 60 mile on it since it has been put together.

I have a header evac setup, could this be causing any of the symptoms? I was thinking about switching to it a regular filter/pcv setup since I'm not up in the rpms all the time. I know the valve covers do condensate because when I pulled them off to check the valve clearances there was a decent amount of moisture on them. I am using 10w30 oil so I don't think that it is too thick or too thin.

Like I said before i just wish it was consistent so it would make finding the problem easier.

72' F100 398W
NUTNDUN is offline  
post #11 of 59 (permalink) Old 04-17-2009, 09:48 AM
Premium Member
 
Join Date: Sep 2004
Location: Sunny Arid Desolate Port Orchard WA
Posts: 34,853
Re: Random 5 - 10psi oil pressure drop

The Evac system will NOT effect your oil pressure...

Gauges.... Could be the gauge...
FEandGoingBroke is offline  
post #12 of 59 (permalink) Old 04-17-2009, 12:09 PM Thread Starter
Registered User
 
Join Date: Oct 2007
Posts: 141
Re: Random 5 - 10psi oil pressure drop

I found something else that sparked my interest. I found a pinhole in my one heater hose, it doesn't leak but if you squeeze the hose you can see if bubble. The last two days I have had the heater on. Could it be sucking air and causing air pockets in the cooling system and causing different areas of the oil to be warmer then others? Maybe pockets of hotter oil and causes the pressure to drop for a second and come back.

72' F100 398W
NUTNDUN is offline  
post #13 of 59 (permalink) Old 04-17-2009, 12:11 PM
Premium Member
 
Join Date: Sep 2004
Location: Sunny Arid Desolate Port Orchard WA
Posts: 34,853
Re: Random 5 - 10psi oil pressure drop

No, it cannot, not ever. never ever... never ever ever ever....
FEandGoingBroke is offline  
post #14 of 59 (permalink) Old 04-17-2009, 12:13 PM
Premium Member
 
Join Date: Sep 2004
Location: Sunny Arid Desolate Port Orchard WA
Posts: 34,853
Re: Random 5 - 10psi oil pressure drop

Yes it can pull in AIR, but ONLY when the engine is on a Cooling down session, which only occurs when coming down a long grade or after the engine is shut off...

But the circulating water temp can never ever ever ever ever do what you asked to teh pressure.
FEandGoingBroke is offline  
post #15 of 59 (permalink) Old 04-17-2009, 12:35 PM Thread Starter
Registered User
 
Join Date: Oct 2007
Posts: 141
Re: Random 5 - 10psi oil pressure drop

LOL, it was worth a shot wasn't it? I have to drive home then and I will keep an eye on it and see what happens and see if it does it anymore.

72' F100 398W
NUTNDUN is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Muscle Forums : Ford Muscle Cars Tech Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
just a random joke NoLongerHere2 The Garage 7 04-13-2005 07:23 PM
oil pressure drop when hot.. Sixt9coug Galaxie Pages 5 04-08-2004 10:00 PM
Oil pressure drop on right hand turns! Cobra460 All Ford Techboard 9 07-22-2002 11:54 AM
How much drop in fuel pressure is tolerable? ville All Ford Techboard 2 06-26-2002 08:55 AM
Oil Pressure Drop Cobra77 All Ford Techboard 6 02-02-2002 01:12 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome