22 replies to this topic

[powermadcoop]

1992 SPi Mini

Hello all

just a quickie

Ive noticed recently that my motor seems to have lower pressure than it used to. on idle when fully warmed up the pressure reads about 12 on my gauge. doesnt smoke or anything. sometimes does flick up and down between 12 and about 20 in a constant up down up down motion.

Oil level is just below maximum and was changed about 3 months ago.

I did notice the other week then when I was giving it some beans at about 5500-6000 rpm i lost power and got some smoke out the back so havent driven it that hard since then. not sure if thats related to the oil pressure. the pressures been low for a couple months now and the smoke out the back was just a few weeks back.

Worth a change of oil filter in case its blocked? potential oil pump problem?

Any helps appreciated

Ta

Joel

[sx_turbo]

change the oil and filter and see how you get on.

what is the oil pressure at 3000rpm?

[powermadcoop]

off the top of my head when warmed up about 25-30.......

[sx_turbo]

thats to low,

could be a few things

oil pump,

main bearings

bigend bearings

faulty oil pressure relief valve.

at 3000 rpm, the pressure should be roughly 45psi - 55psi,

whatever the problem, it wil only get worse, and all scenario's will result in at least taking the engine out for inspection

[powermadcoop]

so we reckoning, change the oil filter, then the pump then the oil pressure relief valve (to ball bearing type)

then if thats not sorted it were thinking its something big??

[sx_turbo]

try changing the oil and filter, but use an engine flush this time, and see how it goes, but thats really clutching at strwas mate.


it's more than likely something majour, and the more you leave it as it is, the more damage you will do to the engine, and the bigger chance of it costing you more money.


how many miles has the current engine done? if close to 100,000 miles or more, then chances are it's due a rebuild any way.

what oil do you use?

if you use cheap oil (comma classic, unipart 20w50 and other such oils) then when your thrashing it, the chances of the oil breaking down and causing engine damage are much much higher, if you use the likes of millers mini 20w50, or valvoline vr1 20w50 then the chances of oil breakdown when having a sunday hoon is greatly reduced.

the reason for this is the qaulity of oil used to make it in the first place. yes they are built to a spec set by the governing body,

[powermadcoop]

I had a rebuild dont about 30K ago. a very costly one at that!!

I use castrol GTX magnatex as recomended by sprocket.

hmmmmmmm what to dooooooo

[sx_turbo]

well believe it or not imo taking the engine out, and taking the gearbox off, and inspecting the big ends, and mains and the oil pump, will be more cost effective than replacing things in stages,

because in between times while your trying these things out, it could cause more damage and cost you more money.

and you will know exactly what the problem is.

and castrol gtx magnatec is actually crap. castrol rely on there name brand with great marketing these days, as do mobil 1.

never skimp on oil, it's the life blood of an engine, the valvoline stuff also isnt that much dearer through the motor factors i work at, than it is to buy the castrol gtx stuff from halfords.

change the oil and filter first using a flushing additive like wyns engine flush, and see how it goes.

if the oil pressure is still woefull, i think you need to prepare for the worst.

(i dont mean to sound doom and gloom)

do you run an oil cooler?

[powermadcoop]

cheers for the oil info, I dont run an oil cooler no.

ill do the above as soon as I get chance. more than likely this weekend.

with regards to the engine flush.... how do these work? do i need to run the car with this engine flush in for a certain amount of miles and then change the oil?

[miniobsessed]

15 psi is the 'norm' for idle oil pressure. It is governed by the internal characteristics of the engine (ie bearings clearances, oil pump wear, gunk in oil galleries, etc...).

The next important thing is that you have good oil pressure at about 3000 rpm (as has been stated previously). This is primarily governed by the oil pressure relief valve (but will also be influenced by the type of oil you are using, bearing clearances, etc, etc...) and should be 60 - 70 psi.

If this is what you are seeing on your gauge then I wouldn't be too worried about an oil pressure problem. Although you may have another issue. If you are not seeing this you have an issue that you need to take care of asap before it becomes terminal.

Personally I would not use an oil flush in an engine. If you are keen to try and 'clean' your engine before changing your oil I would add a litre of diesel (which would be a lot cheaper than 'snake oil') and run for 10 - 15 minutes... This is only something I would do on a 'new' engine as on an older engine it is only likely to dislodge something that will end up running your bearings.

[Lukie-J]

I'm having a similar problem (998cc carb) oil pressure light comes on when engine is warm and on tick over but goes away at around 1500 rpm. The head gasket is being done next week along with an oil and filter change.
Also, but probably un-related, there is a small oil leak from the drive shaft oil seal. If I sort these things will it remedy the oil pressure problem?
I have already fitted a new pressure switch and release valve.
Cheers.

[miniobsessed]

I'm having a similar problem (998cc carb) oil pressure light comes on when engine is warm and on tick over but goes away at around 1500 rpm. The head gasket is being done next week along with an oil and filter change.
Also, but probably un-related, there is a small oil leak from the drive shaft oil seal. If I sort these things will it remedy the oil pressure problem?
I have already fitted a new pressure switch and release valve.
Cheers.

Doesn't sound healthy... I'd be checking it properly with a pressure gauge before you do anything though. I'd also try a slightly thicker oil (with the pressure gauge still attached) and compare with what you have now.
If it's a high mileage engine your oil pump could be one the way out and if you don't fix it up soon it could also lunch your bearings, crank, cam, etc... but it could be that it is just a little worn out and needs the pump, bearings, etc replaced.

Also, your leaky drive shaft seal will not cause a drop in oil pressure (unless it causes you to run out of oil ) as the gearbox (sump) is not part of the pressurised oil system.

[Kam]

I take it SPI's run the same metal pipe from the oil filter to block as on the carbs? Have you still got the metal pipe there on yours and does it leak atall? My carb one didn't but I replaced it anyway

Check this link from here Clicky

Just something else to check

[Lukie-J]

Ok, cheers for that. Going to do the head gasket tomorrow and will change the oil and filter at the same time.

[powermadcoop]

Change of filter fixed the problem straight away.full service last weekend!! Must have just been bunged up