So…I need advice.

I was driving down the road and an orange light started to flicker on the dash and eventually glowed steady. Since my classic Mini was new I drove to the house and opened up an electronic copy of the owner’s manual and found out it was the oil pressure warning light. Got on the internet and searched for related issues.

The next morning I started the car and the light remained off for about 10 minutes but then began to start to flicker. When the engine was at higher speeds it would go off completely. I parked it at the house where it has remained ever since.

I changed the oil and filter but then the light stayed on steady all of the time.

I ordered and installed a new oil pressure sending unit but the warning light still stayed on.

I bought a mechanical gauge, and when started, showed no pressure and no oil was seen in the clear line.

Does this sound like it may be the oil pump? The engine had been running fine with no knocks, odd sounds or smoke. The oil level is at the full mark. When I ran it, I had the breather cap open so I could see the rocker arms moving but I did not notice any oil splashing around like on my old V8.

Barry

 

what year is your Mini? I am not familiar with a oil light in a Mini unless someone installed it or this is a late model. I am also confused on you saying "My classic Mini was new" do you mean new to you????

 

New to me; I have had it about two months. The title says 1977 but the trunk handle has 92 on it.

 

As additional information, I removed the oil pressure relief valve (cap, spring and thimble) and turned the engine over...oil shot out of the hole. I did the same thing on the oil pressure sending unit with the same result.

Now when I start the motor and it idles high, the warning light goes off.

Any ideas?

 

sorry to say it, but I'll just add this to the list of why not to buy a re-vin


I bought a mechanical gauge, ....
Now when I start the motor and it idles high, the warning light goes off.


what does your mechanical gauge say when the light goes off?

1. Do you have a Haynes manual?

2. Hang some pictures of your engine so we can try to identify it. What do you THINK you have?

 

May try a thicker oil as well

 

the general Mini recommendation - given the mixed engine and tranny thing

is 20W - 50 . . . .

with the tranny factor I don't think I'd wave too far from this . . .

 

I will try these things tomorrow afternoon and post.

 

Is it possible that the oil pickup tube in the sump has become loose or broken? Could the pickup tube's strainer become clogged?

 

I have attached photos of the engine. I believe it is the 1275cc.
http://www.flickr.com/photos/94637064@N06/

I have the Hays manual and old service PDFs.

The oil pressure is about 7psi at idle and about 18 psi at 45MPH.

 

I think the old rule of thumb is that for every 1000 RPM you should have at least 10 PSI of oil pressure. 18 PSI at 45 MPH seems way too low if you have a typical 3.44 final drive. You may need to investigate further- exhaust color, oil consumption, cylinder pressure, etc. Good luck!

 

all engines operate at different oil pressures. I wouldnt say that 10 psi per 1000 rpm is a good measuring stick. I have had old mopars and still do and they idle at 80 to 90 psi. a classic chevrolet or ford is around 25. both are fine for their brands. I would say to keep asking around it sounded like the pump when i read it, they usually go after sitting a while on older cars and when they do they tend to have trouble keeping any pressure at idle , once moving they seem fine, I had an old cougar the dummy light would flash at idle constant but if you got moving it was gone and then on deceleration it would start again.

 

your carb looks like a later HIF-44 or 6 (nearly identical) and points to your car being a 90's if everything is original.

I have a 1275 A+, somewhat tweeked, with an HIF-6 (1.75 inch), large center bore exhaust, sport intake manifold, K&N cone, and re-needled for the cone filter. My car likes to idle around 1000 cold which is a little high according to the books but in 8 years of playing around I've decided if it is happy there and when hot it drops to around 850.

On a cold engine at idle, and a hot engine at 3000 rpm plus I see 45 - 50 psi on my oil gau'. At idle on a hot engine the oil will drop to around 25 psi. I'm running 20W-50 with ZDDP additive. Is my gau' accurate? I dunno . . . but my car runs fine and when I've adjusted the valves everything is oiled and shines pretty. I don't have an idiot light for the oil p' (numbers adjusted, I paid attention on a longer drive today)

"I bought a mechanical gauge, and when started, showed no pressure and no oil was seen in the clear line."

you won't see oil in the line unless you open the line at the gau end and bleed the air out to get oil up there. You do not need to do this however as pressure is pressure and the air is getting compressed and the PSI reading should be accurate - or so I was told when I asked if I should bleed the air out of this line. Over time oil is going to migrate up this line. I see oil about 2/3 of the way from engine to gau' now and interspersed oil and water the rest of the way to the gau.

and b4 someone else jumps in here, yes you may want to consider changing the plastic line to a metal reinforced one cuz if the plastic pressure gau line let's go you will empty the crankcase/tranny pretty fast and messily!

 

+2 on switching from plastic to copper. I went the 'easy' route on my '68 SAAB Sonett and tied the plastic line up and out of the way but on the Thruway outside Utica that line softened and oozed onto the exhaust and cost me a tow and a used v4 engine ($350 installed as I recall).

 

So...what is your suggestion based upon what I have said?
1. Keep a watch for now only.
2. Replace the oil pump, etc.
3. Rebuild the engine (since it is already out and can get a fresh start from here forward).

- Is running fine except for warning light, (no smoke, knocks)
- oil pressure is 7-18 instead of spec 15-60

 

You pressure sounds low to me but I'm NO EXPERT.

here's my best suggestion

I know a guy in Jacksonville who's rebuilt a few Minis - sign up over there and send the question to him . . . BobbieMartin on SunshineMinis.org

He's the guy I'd ask, and/or call Seven and ask them (but I don't like to take much time there unless I'm ready to spend some $$ too)

Did you try asking this on the MiniMania boards?

 

I had this problem with my mini - a 1275 A+. Oil pressure warning light would go on after the engine warmed up and on idle but would turn off once the rpm's increased. Turns out the oil pressure relief thimble was pitted and scarred and would not hold pressure. I replaced the oil pressure relief valve spring and thimble with a new spring and ball bearing (http://www.minimania.com/part/BLS916/). Also installed a mechanical gauge since I heard the oil pressure switch for the warning light is too low (should be closer to 20 psi than 7) - oil pressure is in the correct range now.

I'd try the cheap replacement first before tearing into the motor.

 

I would also recommend that you do a compression test just to rule it out.

 

A silly question .....but what oil is in the engine........as the A series and A+ need 20/50 oil like Corma/Pentrite classic oils http://www.penriteoil.com.au/product...d_viscosity=17
in it to work efficiently.......do not use any synthentic or race oils

 

The problem started with the original oil in the car when I bought it - I am not sure what it was. I changed it with 10/40 and a can of STP. I have a new oil pressure relief valve assembly ordered, and when I install it, will switch to 20/50.

 

sounds like a reasonable plan

are you guessing or was this a specific recommendation from someone?

there used to be an adjustable relief valve ... ah yes, found it at Seven
http://www.7ent.com/products/oil-rel...le-for014.html

altho its purpose is to deal with TOO MUCH pressure.

 

have you found out what CC your engine is yet 998cc, 1098cc, 1275cc
going by pis its hard to see has it still got engine NO: stamp on top of block above alternator.........this will give us some clues.......take a pic of front of block L?H side where oil pipe to filter is and we can dertimine if you have an ajustable relief valve........

 

I have attached photos of the engine. I believe it is the 1275cc, based upon the numbers
http://www.flickr.com/photos/94637064@N06/

I took the oil pressure valve out ( a spring and thimble only ); the new one ordered has not arrived yet.

I have not seen a cut-away drawing of how the oil pressure relief valve works but I would guess that the oil pushes against the thimble, and the thimble's movement is limited by the spring to a point. If the spring is weak or the thimble pitted, oils could free-flow past it and pressure would drop???

I should have the part in a couple of days and be able to give it a try.

 

No pressure after changing the oil pressure relief valve. Changing the oil pump is next on the list...I picked up an engine lift and stand and am clearing the garage area.

Barry