ausmini :: View topic - Sudden oil pressure INcrease!

Thanks for the reply Mickmini. What would have caused the bypass valve to close, given that I still have this high oil pressure after the filter change?

Is it realistically possible to have 70-75psi hot on an engine of unknown age/history, running a cheap mineral oil?

One option is for me to screw out the pressure relief valve (I have an adjustable one) down to say 60psi, but this would only deal with the symptom, not the cause.

I substituted in another Smiths gauge yesterday, but no change to the readings.

Could be worse I suppose, it could be low oil pressure - but it would be nice to pinpoint a cause.

Cheers
Matt

Mine is a ball bearing, with a cutoff bolt up the guts of the spring to give it support - took advice from this forum on that issue a while ago.

Thanks Phill. Mine is a ball bearing, with a cutoff bolt up the guts of the spring to give it support - took advice from this forum on that issue a while ago. Just took it out and it all looks the way it should...
Interesting that you get 65-70 hot - I didn't know that was possible. What oil do you use?

Matt

Interesting that you get 65-70 hot - I didn't know that was possible.

Matt

Thanks for the reply Mickmini. What would have caused the bypass valve to close, given that I still have this high oil pressure after the filter change?

Author:	MattE [ Wed Dec 31, 2014 6:29 pm ]
Post subject:	Sudden oil pressure INcrease!
Folks, Interested in views on what might have taken place with my car yesterday (1275 A+) - I noticed that the hot oil pressure (at speed) is 70-75psi. The car has always done 50-55psi. Recent oil change (XLD before and after), and an oil cooler recently fitted. Drove around today without the cooler plumbed in, and no change - still 70-75psi. Oil filter changed late yesterday and cut open for interest's sake - almost no material collected. Oil pressure relief ball & spring removed & checked, no worries there. As I have an adjustable oil pressure relief cap, I could wind it back to give, say, 60psi hot, but I can't help but think something has caused this - but what! (Oil pressure is normally too low, not too high!) Thanks in advance, Matt

Author:	mickmini [ Wed Dec 31, 2014 7:09 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
Bypass in the filter housing was open before and now closed?

Author:	MattE [ Thu Jan 01, 2015 10:23 am ]
Post subject:	Re: Sudden oil pressure INcrease!
Thanks for the reply Mickmini. What would have caused the bypass valve to close, given that I still have this high oil pressure after the filter change? Is it realistically possible to have 70-75psi hot on an engine of unknown age/history, running a cheap mineral oil? One option is for me to screw out the pressure relief valve (I have an adjustable one) down to say 60psi, but this would only deal with the symptom, not the cause. I substituted in another Smiths gauge yesterday, but no change to the readings. Could be worse I suppose, it could be low oil pressure - but it would be nice to pinpoint a cause. Cheers Matt

Author:	phillb [ Thu Jan 01, 2015 1:09 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
MattE wrote: Thanks for the reply Mickmini. What would have caused the bypass valve to close, given that I still have this high oil pressure after the filter change? Is it realistically possible to have 70-75psi hot on an engine of unknown age/history, running a cheap mineral oil? One option is for me to screw out the pressure relief valve (I have an adjustable one) down to say 60psi, but this would only deal with the symptom, not the cause. I substituted in another Smiths gauge yesterday, but no change to the readings. Could be worse I suppose, it could be low oil pressure - but it would be nice to pinpoint a cause. Cheers Matt Double check the relief valve, I'm not sure how the adjustable ones work (are they a ball??) ....when mine was sticking one time (standard bullit shape one) it jammed closed and my oil reading went off the scale (100psi plus) and sometimes would jam open and give very low reading. I normally tend to get a reading of around 65-70 hot at speed (and it's not a new engine). The standard valve is supposed to give around 70-75psi max I believe.

Author:	MattE [ Thu Jan 01, 2015 3:45 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
Thanks Phill. Mine is a ball bearing, with a cutoff bolt up the guts of the spring to give it support - took advice from this forum on that issue a while ago. Just took it out and it all looks the way it should... Interesting that you get 65-70 hot - I didn't know that was possible. What oil do you use? Matt

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Author:	iamstib [ Thu Jan 01, 2015 4:01 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
I dont know how to fix ur issue but i run 75-80 psi hot and the engine was rebuilt over 15yrs ago?

Author:	MattE [ Thu Jan 01, 2015 4:12 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
Thanks - it sounds like the oil pressure I'm seeing isn't a real problem - but how it came to jump 20-25psi is a real mystery. I wonder if it passed a stone?

Author:	winabbey [ Thu Jan 01, 2015 4:13 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
MattE wrote: Mine is a ball bearing, with a cutoff bolt up the guts of the spring to give it support - took advice from this forum on that issue a while ago. The Doc was a supporter of the ball for a long time but I seem to remember he changed his recommendation back to using the standard arrangement in the last year or so. He may come on to elaborate, or do a few searches and you may find the post with the reason(s) he reverted.

Author:	iamstib [ Thu Jan 01, 2015 4:20 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
When i changed my oil and filter last time... My gauge went from 75 all the time to 50 on idle and 75 while driving? Dunno why either but all seems be going fine

Author:	phillb [ Thu Jan 01, 2015 6:56 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
MattE wrote: Thanks Phill. Mine is a ball bearing, with a cutoff bolt up the guts of the spring to give it support - took advice from this forum on that issue a while ago. Just took it out and it all looks the way it should... Interesting that you get 65-70 hot - I didn't know that was possible. What oil do you use? Matt Valvoline XLD classic. Although that is now mostly no longer available and is being replaced with XLD premium. I just use the old standard bullet shaped valve.

Author:	drmini in aust [ Thu Jan 01, 2015 9:46 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
I am still using a ball in mine, but I've seen some problems with this mod, unless you use a new spring. If the spring gets bent it tends to push the ball sideways, off its seat. Putting a bit of straight 5/16" steel rod inside works, but you want the spring straight to avoid problems. So don't use the old spring if it's bent at all. IMO the original valve works well, as long as metal shavings in the oil doesn't jam it. This is really its only problem. The ball avoids this as it is smaller diameter and there's plenty of clearance.

Author:	phillb [ Fri Jan 02, 2015 7:50 am ]
Post subject:	Re: Sudden oil pressure INcrease!
MattE wrote: Interesting that you get 65-70 hot - I didn't know that was possible. Matt That's belting along at 110 kmh, idle is usually around 25psi.

Author:	mickmini [ Fri Jan 02, 2015 8:05 am ]
Post subject:	Re: Sudden oil pressure INcrease!
MattE wrote: Thanks for the reply Mickmini. What would have caused the bypass valve to close, given that I still have this high oil pressure after the filter change? THe bypass valve is just a ball and spring. It could get jammed by crud just like the releive valve. You can take the housing off the blockand check it is closing properly.

Author:	Pottsy [ Fri Jan 02, 2015 2:11 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
Gents. I seem to recall a similar issue being described to me when I visited the Willson's in Hobart many years ago. The car was a Clubman with excessive oil pressure, so excessive that a test gauge was spat across the workshop! The usual suspects were checked and the pressure relief valve was fine. What was eventually found, and it took a lot of head scratching on the Willson Laddie's part, was this: The pressure relief valve seats on one end of a pressed-in sleeve that also incorporates the relief hole that allows excess pressure pushing past the relief valve back to the system. This sleeve had come loose so that under pressure the pressure relief valve, and the sleeve, were being pushed up the bore against the spring. This meant that the sleeve was covering the return hole in the block casting and causing no regulation of pressure. With no regulation, it just keeps going up until the leakage limit of the oil pump, or something else in the system, is reached. Once they worked this out and were able to glue and stake the sleeve back where it should be, the problem went away. It's worth mentioning that until I heard about this fault, I had no idea that the seat for the oil pressure valve was a separate part. I always assumed it was simply a bore in the block. Shows to go you never stop learning! (and you probably should look closely at cutaway drawings as well!) I thought I wote this fault up in the Mini Experience magazine, or possibly in "Inside the Greasy Bits" but can't find it so far in my archives. Worth checking anyway as it's a likely cause of your symptoms. Cheers, Pottsy

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Author:	Convertible Mini [ Fri Jan 02, 2015 2:44 pm ]
Post subject:	Re: Sudden oil pressure INcrease!
Yes The relief Valve Seat is a removable part. There is also a difference between the one in a manual Block and the Auto Item. To remove this seat one has to normally tap a thread in it and use a long enough bolt to pull it out. I remember changing the one in the 1380 engine which I changed from Auto to Manual.