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Low oil pressure.
https://www.ausmini.com/forums/viewtopic.php?f=2&t=75166		 Page 1 of 2
Author:  mogadon [ Wed Jan 25, 2012 4:46 pm ]
Post subject:  Low oil pressure.
Hi everyone.

I have been looking for a mini for a while and I'm (hopefully) getting pretty close to buying one now, thanks to my 'wanted' post on this forum.

I looked at it last night. I am very happy with the interior / exterior and also that it is genuine. The engine / mechanics however are my weakness. The oil pressure is the one thing that is sticking in my mind. During the drive it never really got over 50.

After reading a bit on here and speaking to a couple of people I understand it should have gone up to around 75 ...?

The fella selling the car seems very genuine and he seemed to think that it could have something to do with a new pressure release valve that he recalls was installed when the engine was reconditioned by a previous owner.

Also I get the impression that it is a while since the oil has been changed (time not kms) ... how much could this affect the pressure?

Thanks,

Mog
Author:  Wombat [ Wed Jan 25, 2012 5:17 pm ]
Post subject: 
If the oil hasn't been changed for a while it is likely the filter may not have been changed and it's blocked - also if it has an original relief valve it may not be closing properly. Oil pump could be knackered ( for your sake hope not) Others may have extra to contribute.
Author:  goodie [ Wed Jan 25, 2012 5:32 pm ]
Post subject: 
How long ago was the engine rebuilt , mileage , years ?

What pressure did it have at idle ? , and was the engine up to operating temp ?

Whilst pressure was at 50 psi , what revs was the engine doing ?

If unsure , you could put an oil pressure master gauge on the engine , to see exactly what pressures are doing, ( just in case the gauge in the car is reading low ? )
Author:  ryan [ Wed Jan 25, 2012 5:48 pm ]
Post subject: 
If you aren't sure, take someone who knows minis to have a look with you, or take it to a local mini mechanic.


I have seen cars with similar oil pressure and they are fine.

You could also ask the owner to do an oil change on it before you buy it and see if that makes a difference.
Author:  Morris 1100 [ Wed Jan 25, 2012 5:57 pm ]
Post subject: 
50 psi isn't bad.
40 to 50 is fairly normal for a stock motor.
Author:  drmini in aust [ Wed Jan 25, 2012 6:05 pm ]
Post subject: 
When new, non-Coopers were about 60psi. Coopers were ~70.
50psi is OK, if it gets down to 40 in normal running IMO the bearings and pump are on the way out.
What 20W/50 oil is in it can affect the pressure too. Some (eg GTX) are notorious for losing pressure during freeway running.
Author:  mogadon [ Wed Jan 25, 2012 8:00 pm ]
Post subject: 
thanks for all of the quick responses. the mini i am looking at is a 997 cooper if that helps.

Quote:
How long ago was the engine rebuilt , mileage , years ?

1999 and ~4k miles

Quote:
What pressure did it have at idle ? , and was the engine up to operating temp ?

i didnt check the idle pressure personally but when i mentioned it to the seller today he said that it idles around 25


Quote:
You could also ask the owner to do an oil change on it before you buy it and see if that makes a difference.

thanks, i had thought same .. will do.

thanks again for all of your help. regarding getting a pressure test done and an overall engine health check done ... does anyone know 'rally motors' in geelong? I googled "classic car mechanic geelong" and they came up.
Author:  goodie [ Wed Jan 25, 2012 8:23 pm ]
Post subject: 
If it's holding 25 psi at idle , i 'd wouldn't be too concerned about it .

As Doc and Morris said , 50 psi isn't too bad .
Author:  simon k [ Thu Jan 26, 2012 10:06 am ]
Post subject: 
I won't accept 25psi, thats too low.

Sounds like the seller knows that it always idles around 25psi, I'd doubt an oil change would fix it. Unless he always uses rubbish oil...

4000 miles in 13 years isn't very much, at a guess I'd say it's always been driven gently, so unless something has gone wrong, then it would have been a crappy engine rebuild. Ask how many times he's changed the oil in that 13 years, ask if he has receipts for the rebuild, some people do try to re-use 40 year old oil pumps

How do you plan on using it? if you're going to baby it and only take it to shows, then you'll probably have no trouble, but if you plan on using it regularly, I don't think it'd last long. It's not like it's easy to find a 997 crank if you drive it a lot with issues and the crank gets damaged beyond repair
Author:  mogadon [ Thu Jan 26, 2012 11:53 am ]
Post subject: 
Thanks Simon,

Appreciate the advice re being cautious of damaging the crank as I plan on driving it regularly.

Also, would there be any way to determine if the crank is already damaged?

Also ... what sort of cost might I be up for, worst case, to fix the oil pressure issue? New pump $?, full engine reco $?

Cheers,

Mog
Author:  simon k [ Thu Jan 26, 2012 12:08 pm ]
Post subject: 
mogadon wrote:
Also ... what sort of cost might I be up for, worst case, to fix the oil pressure issue? New pump $?, full engine reco $?


professional mini specialist engine out, correct issues/rebuild, reinstall - maybe $4K? - lots of caveats on that obviously!

new oil pumps themselves are about $50, but the work to install is a different story, and I'd never do just the oil pump without doing the bearings as well...

To use a 997 cooper (which is a rare and quite special car) as a regular driver, I personally would take the 997 out, preserve it, and put in a standard 998/1098. The 997 will always be there to put back in

That's what I've done with my Cooper S, the original engine is on my shelf and I use a "throwaway" motor. The original motor had some issues when I bought the car, I used it for a bit, and when the time came I swapped it for one that doesn't matter if it explodes. The original motor just needs a freshen up when I'm ready to treat the car like an ornament
Author:  drmini in aust [ Thu Jan 26, 2012 2:45 pm ]
Post subject: 
I agree with Simon.
I would add that 997 cranks are getting like rocking horse droppings now, that's another reason to stick something else in it as a daily driver.
If you use a 1098 with the twin carbs off the 997, it'll have more power and torque than original too.
Author:  smac [ Thu Jan 26, 2012 6:19 pm ]
Post subject: 
I guess I'm somewhat cynical, not having one to store, but whenever I hear about people taking the rare running gear out so it doesn't get worn out (cooper, s, whatever) I find myself wondering just when it will go back in. I'm picking never..... 8)

SO take it out, sell it, and rebuild one you're prepared to drive :lol:
Author:  drmini in aust [ Thu Jan 26, 2012 6:32 pm ]
Post subject: 
smac wrote:
I guess I'm somewhat cynical, not having one to store, but whenever I hear about people taking the rare running gear out so it doesn't get worn out (cooper, s, whatever) I find myself wondering just when it will go back in. I'm picking never..... 8)

SO take it out, sell it, and rebuild one you're prepared to drive :lol:

Haha, my Cooper S motor is in storage (we sold the Cooper S in 1984 with a Morris 1100S motor in it).
It's my `superannuation of last resort' :P
Author:  Morris 1100 [ Thu Jan 26, 2012 7:06 pm ]
Post subject: 
I think it would depend on the usage. Simon is happy to use his Cooper S everyday but wants to keep the S motor safe.
Some other people may not use the rare type of cars everyday and wouldn't have any concern with clocking up a few thousand miles a year.
I can understand both views.
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