24 replies to this topic

[Austifiniho]

You have low oil pressure. Would rather not rebuild the engine. What do you do to try to fix it?

Engine is on 89,000 miles. So could need a rebuild, but I want to make sure I need one as this is my daily driver and have no other car, will have to get another car while I rebuild it so it’s gonna be expensive

[MIGLIACARS]

how low

[sledgehammer]

as above -- how low is low - hot & cold idle & revving in psi if possible-

 

is gauge correct ? knocking ?? how long for oil light to go out ?

 

change oil , oil filter , use correct grade oil (can of worms opened)

 

make sure relief plunger isn't stuck open a bit

 

pull it out & give it a polish up - check the body & seat , check spring

Edited by sledgehammer, 28 July 2018 - 07:21 PM.

[racingbob]

if pressure is good say 75 coldish engine say 4000 revs and goes to say 45 hot more than likely main bearings. oil pump. was on my race mini

[Spider]

At 89 000 miles, it is getting long in the tooth.

 

You could try just fitting a new oil pump, but don't get your hopes up.

[Austifiniho]

When hot were showing as 5psi at idle. Temp gauge is at 90-100.

[Austifiniho]

It is getting up there with increased revs. I’ll check tomorrow exact figures.

[sledgehammer]

I would run it till it dies - save your pennies meanwhile

 

as moke says - getting a bit old if totally original

or look for a known good engine that you definitely know is good

 

worth an oil change & filter - just to extend the life a bit - also check relief valve as above

[mini13]

if its lust low at idle i wouldnt worry too much, as long as youve got 40psi driving thats ok. even at 30psi it'll probably still last some years.

[Homersimpson]

About 20 years ago when I started working on minis we used to put a Cooper S ball and spring into the oil pressure relief valve to increase the oil pressure on a worn engine.

 

Obviously not a long term solution but if you have more oil going around it can't be a bad thing especially at idle when pressue is at its lowest.

[Dusky]

About 20 years ago when I started working on minis we used to put a Cooper S ball and spring into the oil pressure relief valve to increase the oil pressure on a worn engine.

Obviously not a long term solution but if you have more oil going around it can't be a bad thing especially at idle when pressue is at its lowest.

That doesn't even work.

Also, @OP, 5 psi at idle is very very low. Is that with a quality 20/50 oil?

[Homersimpson]

 

About 20 years ago when I started working on minis we used to put a Cooper S ball and spring into the oil pressure relief valve to increase the oil pressure on a worn engine.

Obviously not a long term solution but if you have more oil going around it can't be a bad thing especially at idle when pressue is at its lowest.

That's a lie and doesn't even work.

Also, @OP, 5 psi at idle is very very low. Is that with a quality 20/50 oil?

 

Thats  wrong, the Cooper S Ball and spring can increase engine oil pressure as below:

 

https://www.minimani...ring---Cooper-S

 

http://www.minispare...36.aspx|Back to

 

The pump in an engine is usually capable of far more oil pressure than required and the pressure relief valve dumps oil back into the sum to reduce the output pressure to the required level.

 

When the bearings start to wear the gaps around them get bigger, more oil is lost through them in the same amount of time and the overall system pressure is therefore lower which results in lower pressure and possibly low oil flow to other components like the cylinder head rockers. 

 

By increasing the pressure you may get more oil around the system which will save other components in the engine from requiring replacement/reconditioning and as long as the running pressure isn't too high then this should be ok.

 

Whilst 5PSI at idle is very low it is the running pressure which is more important, of course if the pressure has suddenly just dropped the pressure relief valve may be sticking/damaged/have something stuck in it so its worth taking the old one out and cleaning and checking it.

[GraemeC]

Dusky May have been harsh, but he was also right.

Putting an S ball and spring in, which means the oil pressure RELIEF point is higher, is not going to make the pump create more pressure.
5psi is a far lower pressure than the std spring would allow the pressure relief valve to open, so increasing that spring pressure (which is what the S spring does) is not going to make any difference.

The S spring will only increase pressure if the pressure developed in the system is higher than the standard spring can control.

[racingbob]

I've tried ball bearing in the past and hasn't helped when hot

[MIGLIACARS]

Its a cheap try may be worth giving it a shot who knows. Not worth ww3 on here.

 

new oil and filter cannot make it any worse.

As a road car it may rattle on for years if treated well it may go bang tomorrow.

dont rev it to death new oil every 2000 miles good stuff and stretch the spring, its worth a shot.