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Re: Oil pressure problem.

To: "Jacques Dupuis" <JDMG@msn.com>, MGS@Autox.Team.Net
Subject: Re: Oil pressure problem.
From: joseph_cianciotti@ccmail_gw.gmosf.com
Date: Wed, 05 Mar 97 18:26:43 PST
I came across something at the MG Owners Club's Virtual Octagon (http://
users.ccnet.com/~jensten/)  that may be of some help.  Joseph

Oil Pressure Lag
By Marty Ray

Oil pressure should come essentially instantly on startup. If not, in short
order your engine could be ruined. Possible causes of delay in an otherwise
sound engine are: oil level in sump too low, oil pump loss of prime, pressure 
relief valve stuck open, oil filter drainage or siphon back to sump. The latter 
problem occurred in my car recently. This MGB has an upside down mounted 
filter, 
which relies on a rubber valve-like seal to keep oil from draining back to the
sump. When removed, the filter was empty! A new (and better quality!) filter 
has 
apparently cured the problem, though at first it seemed not to. I am not sure 
why the lag still occurred a couple of times after fitting the new filter. It 
hasn't happened since, but I'm still wary. 

_______________________________________________________________________________
Subject: Oil pressure problem.
From:    "Jacques Dupuis" <JDMG@msn.com> at Internet
Date:    3/6/97  2:10 AM

I would very much appreciate if someone could give me some clues towards the 
resulution of my problem.
THE CAR: 1974 MGB. The engine was totally rebuilt about 6000 mi.ago (3 
years).All internal parts were replaced with new parts and assembly was done 
according to the book. Engine was balanced, all clearances were set to specs 
and assembly was done by an old British Layland pro. (unfortunately, he died a 
few months later). The car is not a daily driver but is only used under ideal 
conditions in the summer time, has never seen any "brutal" driving and the car 
is  a 98 points. Total mileage on the car is 36,000 mi.since new.
THE PROBLEM: When the engine is started from cold after being stopped for 
several hours, the oil pressure takes up to 10 to 15 seconds to buil-up to 
normal. During that time taht looks eternity to me, I can hear some knocking 
and chatter coming from some oil starved parts inside the engine. Once 
pressure is up, everything returns to normal with oil pressure between 55 and 
60 psi, whatever the temperature is. The engine runs perfectly with no signs 
of distress. I know I am preparing myself for a pretty hefty bill but I don"t 
know what to look for anymore.
To try and identify and correct this problem, the following has been done:
New oil pump installed (gaskets are positionned right)
Oil lines to the oil cooler replaced and oil cooler cleaned. Oil presure 
checked with an outside oil pressure gauge (confirming the problem)
3 different brands of oil filter tested ( (top loading)  . Oil changed from 
the regular 20/50 to 5/50 (syntetic), 15/40,10/30,5/40 and 5/30. (Have you 
ever heard someone changing oil and filter 5 times in a week end?) I"ve done 
it. Used oil has been tested by a lab and no abnormal traces of metal or other 
substances were found. Oil pressure relief valve has been replaced and spring 
tension checked according to specs.
The engine will be coming out next week-end and I'll have a look at the 
internal.
WHAT SHOULD I BE LOOKING FOR?
Thank you for your help.
Jacques Dupuis
Magog, Quebec, Canada
BRG 74B


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