Good morning, just joined this forum

I have a problem with my 1967 fiat 500, it has a 595 engine with an upgraded cam and other small mods. I bought the car from Sicily a couple of weeks ago.

The problem is that the oil pressure light sometimes decides not to go off and remains alight. I removed the oil pickup pipe and replaced the rubber sealing ring and problem seems to have been solved as light was coming off immediately on starting, not flickering even when car is running at normal temp. Now I have the same problem again, no oil pressure.
The problem is intermittent, so I'm completely lost. Yesterday it was all fine and an hour later it just went off again. This is not related to the grade of oil as Im using 10W40 and oil is new. When I had the sump off, I also checked the crank bearings and they are practically new, crank was full of oil and everything in there is fully clean.

Did you ever encounter this problem? Can it be related to the pressure relief valve inside the oil pump getting stuck?

Thanks in advance.

Have you checked the condition of the oil light switch?

Im sure its fine as when the car is running and I remove the switch, no oil comes out whatsoever!

fiat500malta said:

Im sure its fine as when the car is running and I remove the switch, no oil comes out whatsoever!

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In that case you have either a faulty oil pump /drive or a blockage somewhere. If you are lucky it will only be a blocked feed to the pressure switch. Are there any other signs of low oil pressure like unusual noise?
If there is any oil pressure at all you should get oil flowing out of the oil pressure switch tapping when you remove the switch.


Robert G8RPI

Even in the rocker arms there is no oil being transported when the oil light is on. Engine works fine though, no strange noises even after 30 seconds with the light on.

Also I read somewhere here that packing the pump with petoleum jelly can help remove any air in the system??

fiat500malta said:

Even in the rocker arms there is no oil being transported when the oil light is on.

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I suspect that most people would agree with me and say STOP running the engine straight away. the rockers should be streaming with oil. It's not likely to be a simple matter of bleeding the system as you've run it enough to mean that oil should be coming through by sheer brute force.
For there to be no oil at all I guess that either something has been cracked or distorted, mis-assembled or left out.
I would be dismantling that engine and checking everything very carefully. It sounds like you've been lucky so far but you're pushing your luck.
Keep us posted as we can all learn and everyone here can also be helpful.

All looks fine if I remove the sump. I also checked the oil pickup pipe for cracks or leaks and its all good. Oil pump out is next!

To me that repair patch at the bend of the oil pick up tube looks like a real bodge job to me & just tack welded in place. I would replace that asap as if it is drawing air there the you won't get any oil pressure. I see you have studs to secure the sump so what sort and size of sump is fitted?

Toshi 975 said:

To me that repair patch at the bend of the oil pick up tube looks like a real bodge job to me

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Very likely nailed it there.

Its a normal sump as far as I know.

I tried to replace the oil pickup tube but somehow the new one did not fit anyways oil pump is out, nothing abnormal it seems!

OK so it looks like you have a standard size alloy sump , not the original steel one which is not a bad thing.
New pick up tube did not fit ? Why not ? Never heard of that.
I would put money on a bet that the tensioners on the timing chain have started to eat through the inside of the timing chain case as that timing chain is so worn and I can see the sag on it. Looks like it was an upgraded kit with that drilled out cog on the camshaft.

I hate to say this, but it looks as if you have a car with a 'front door' warranty! Whoever built that engine up needs his arse kicked--hard! You must DEFINATELY replace that pick-up tube AND the complete timing-chain assembly. There is no way that a new chain should be that loose (and if an upgraded cam was fitted, a new timing-chain assembly should have been fitted---chain and both sprockets). I notice that the oil-pump has been taken apart in-situ--was there not a spring-ring holding the DRIVEN gear and relief valve all together? From experience, it is usually a right bugger taking that ring off with everything in place. I would also (for the relative low cost of parts) also fit a new oil-pump (complete with relief valve). make sure that you fit the correct oil-pump, compatible with the engine number-i.e. a 500 pump if the engine is an enlarged 500 engine, 126 pump if it is a 126 engine --check the engine number--110D (500D), 110F (500F/L), 126A (595cc 126). Packing the oil-pump with VASELINE (petroleum jelly--definitely NOT grease) prior to installing the pump gives the pump something to suck on when initially cranking the engine over. When you have put everything back together, I would be tempted to take off the rocker-cover, remove the plugs (disconnect the coil lead from the top of the coil), turn the ignition on and then crank the engine over until (a) the oil-light goes out and, (b) you have oil coming out onto the rockers.
The oil light is allowed to flicker on when the engine is idling (hot) as long as it goes out as soon as you rev the engine. However, it would seem from the pictures that you have a 3-1/2 litre sump, so the chances of the oil light coming on when the engine is idling is slim.
Lastly, I would fit a new oil-pressure switch and check the electrical connection is sound--if in doubt, re-make it.
All the best--please keep us advised as to outcome--we can all learn something :bang: