Uh oh.... oil idiot light on...

[angello]

Gah.... my '79 Spider 2000 is causing me to loose sleep.....
I know it had been off the road for a good few years prior to my recent acquisition, but I'm now suspecting it had been neglected prior to falling out of use.

First off I've found the cooling system to be in woeful condition.... Looks like the thermostat has been gutted, the heater core bypassed (because it's burst), the radiator fan switch bad and no antifreeze / corrosion inhibitor in sight..... I'm working my way through fixing these problems as I go...

I noticed that the oil pressure idiot light wasn't illuminating (no oil pressure gauge) and on investigating, found the wire unplugged..... On re-connecting, the light illuminates (yay!) but didn't go out on starting (boo!), so I figured the sender was bad and ordered a new one....

On fitting the new sender I find that the light STILL doesn't go out.... uh ohh....

I know there IS oil pressure as I can see the lobes of the camshaft (through the oil filler hole) bathed in oil when the engine is running and it doesn't sound like an engine with no oil pressure.... but the idiot light stays lit, so I have to work on worst case scenario until proven otherwise.
I also noticed that the oil filter doesn't appear to be getting warm, when the sump was getting warm as the engine ran... This kinda suggested to me that maybe the oil filter is being bypassed currently somehow? but I don't know the lubrication system on these well enough to know if this is even possible....

So what's my likely cause? how am I going to confirm if there is actually pressure? and what do I do to fix the light staying on (and NOT by un-plugging the wire like some PO did!)?

[18Fiatsandcounting]

Gaaah!!! is right. Does the light go out when you rev the engine?

Here's what I would do, in order of priority:
1. Check the oil level on the dipstick. Get an accurate level, not just oil scraped onto the side of the dipstick as you withdraw it.
2. Change the oil filter. Don't use an El Cheapo brand. I've heard Wix or Napa Gold are good.

If neither of those is the issue or cures the problem, then I would:
3. Change the oil.

If that still doesn't help, I would:
4. Figure out a temporary adapter so that you can get a mechanical gauge in place of the switch for the idiot light, and get a true reading of the pressure. If you get less than 20 psi when revving the engine, you have an internal engine problem. You should see at least 30 psi and preferably 50+ psi.

By the way, the wire you are attaching to the sending switch is the right one, yes? It should be grey/yellow.

-Bryan

[Nut124]

Loosen the oil pressure switch and start the engine. Does it start leaking oil at the switch? If so then it is seeing the pump pressure and the light not turning off would be a concern to me.

If it does not leak, then someone may have modified the oil filter bracket to bypass the filter, sender. ????

[angello]

Good suggestions all... and in process to work my way through them. New filter on the way

So, essentially there is nothing in the oil filter housing that can relieve pressure? Pressure relief is done in the pump? So IF I do have low pressure it's a matter of taking off the sump and getting to the pump from there....
I'm struggling to believe the engine is completely worn out as it simply doesn't sound it! It runs too well and there isn't any grumbling ends or knocking rod bearing noise and no cam noise either....

We'll see .....

[TX82FIAT]

I'm not sure why anyone would bypass the oil filter housing but is should stick out like a sore thumb if they did. Hopefully you can resolve without needing to get at the oil pump as the pump is located at the bottom of the oil pan and the crossmember is in the way. I'm with the other guys to see if an oil change and new filter help. Is you oil pan dented at all?

[angello]

This just goes from bad to worse.....

As suggested I have ripped into this - changed the ancient filter and on doing so noticed the oil was really thin.... Smells like maybe petrol contamination. I thought this was possibly good news... as the thin oil may have been resulting in low pressure...

So, I changed the oil at the same time as doing the filter. I primed the filter full of fresh, new engine oil, whacked it on and spun the engine over to build pressure.... but the idiot light still didn't go out....

So I pulled the new idiot light sender and checked that to make sure it was working as intended, which it was.

From there I found a mechanical oil pressure gauge and attached that to the oil pressure switch port.... and spun the engine on the starter. Still nothing.... like absolutely nothing.... no flicker on the gauge at all. Pulled the gauge and checked the port wasn't clogged - it wasn't. Spun the engine again to see if oil came out of the pressure switch hole.... nothing. Took the new oil filter back off again and spun the engine again to check for oil anywhere and there IS NONE....

I have absolutely no oil pressure at all

Obviously this is about as bad a scenario as it gets. So where does the oil pump get it's drive from? are there any common failures?

I guess there is nothing else for it beyond pulling the crossmember and getting the sump off

[18Fiatsandcounting]

I guess there is nothing else for it beyond pulling the crossmember and getting the sump off

Before you do that, here are some thoughts. I'm guessing at this point that your oil pump pickup has broken off. This often happens if the oil pan has been whacked with a parking curb or the like. But, if your oil pan is pristine, then this isn't likely the problem.

Here's what I'd do. Add another few quarts of oil to the engine so that you have a total of 7 or 8 quarts in the engine. This will raise the oil level in the sump above the level where the pickup usually breaks. See if you have any oil pressure.

If not, then it probably is time to remove the sump, and you can do this without removing the crossmember. Loosen the engine mounts on either side, disconnect the exhaust manifold, and use a hoist to raise the engine a couple inches. You can then loosen the oil pan bolts (18 if I recall) and remove the pan.

But what's odd is that the engine appears to be running OK. If you truly didn't have any pressure, the engine would have fried itself within a short time. Sometimes there is enough oil sloshing around in the sump so that the crankshaft counterweights sling it around the pistons and such, but that wouldn't get oil up to the camshafts. How long has the engine run (apparently) with no oil pressure?

-Bryan

[Nut124]

Before proceeding to drop the pan, which is a pain, I'd check the following just to learn more and eliminate some possible, while unlikely causes.

1. Remove the oil pump gear cover and crank the engine? Does the gear turn? Does the pump shaft turn?
2. Remove the oil pressure switch and crank the engine. Does oil pour out of the hole?

I have seen a situation where the aux shaft pulley retaining bolt came loose and the pulley backed out far enough to come off the key, but not fall off the shaft. The timing belt cover kept the pulley from falling off completely. Engine was idling w no oil pressure as the pump was not turning.

If oil pours out of the open sender hole when cranking, then the pump is bad as the pressure is not enough to satisfy the switch.

After changing the oil, how long did you crank? It could take a while to develop pressure after an oil change.

Did you state earlier that the cam boxes are full of oil after cranking, idling?

[angello]

Good thoughts guys, thank you

I don't know how long the engine has run without oil pressure ... given that the original symptom of the oil idiot light not going out has now been proven to be a genuine lack or pressure, I fear it may have been running long enough to have toasted the engine - I'm resigned to that .... It doesn't sound rumbly like it's run a bearing, but the jury is out at this stage ....

There is definitely NO oil pressure right now - absolutely none. Nothing comes out of the oil pressure switch hole or any of the oil filter ports and I've certainly spun it over long enough that it should have built pressure following the oil change (I pre-filled the new filter too)....

I thought I had oil pressure at the heads as I could see oil sloshing around the cam through the oil filler hole when the engine was running.... but I'm now thinking it was just sploshing around in the puddle of oil that had gathered around the cam bucket and there may not have been fresh oil getting to the heads... Obviously fresh oil pooled in the cam box when I refilled the engine following oil change....

The engine sump is a little battered, but no more than one would normally expect for an old car and no fresh damage. It doesn't look to have taken a great whack.

So the oil pump is driven off the auxiliary shaft, which is driven by the cam belt, right? and I can see the oil pump gear if I take off the cover ringed red in this picture? As per the advice above, I think that is what I shall have to do next...... If that is spinning when cranking, I'll top up the oil level to see if I have a broken pick up and try again... If not, I'm set to dig deeper....

At the same time, I'm having a thought.... I know the PO changed the cam belt as one the last things they did... maybe that aux shaft pulley has come loose or wasn't tightened onto the shaft properly? I'm just hoping that the pulley has been spinning on the shaft, so the shaft isn't turning and is no longer turning the oil pump drive...... It's just possible that there was enough interference friction to rotate the shaft enough for the pump to feebly pump the super watery, thin old oil around the engine sufficiently to prevent it from completely lunching itself, but adding the thicker new oil has increased the resistance and stopped even that.... I'm clutching at straws here I know ....

[18Fiatsandcounting]

I would do exactly as you suggested: Remove that circular plug cover in the red ring in the picture, and peer down the hole with a flashlight while someone cranks the engine. You should see the top of that gear spinning. Clockwise as I recall. The input shaft for the oil pump is a spline in the bottom of that gear, so if that gear is spinning, your oil pump should be spinning. However, the pump won't pump oil if the pump pickup has broken off.

So, if you see that gear spinning while cranking, then add another few quarts and try again with cranking and watching the oil pressure.

There is only one other thing I would try, and that is to remove the oil filter flange housing that is bolted to the engine block. It's the aluminum molding with four bolts right below where your red circle in the picture is. Where the oil filter screws on. If you crank the engine and see no oil coming out of the block where that housing was attached, you definitely have a problem with the oil pump.

By the way, when you fill a Fiat engine with oil through the exhaust cam cover, a lot of oil will run to the back of the camshaft and over to the intake cam side. So, it is possible to see lots of oil in the top if you have just refilled the engine, even if the pump isn't working.

-Bryan

[Nut124]

What is confusing me is the observation of the cams bathing in oil when idling.

The cam boxes drain pretty completely if the car sits for a while. Oil in cam boxes points to pump moving some oil, or someone poured it in the cam box very recently.

I'm thinking if the pump was turning, even if worn out, oil should be coming from the sender hole when cranking.

Also, idling w/o any oil pressure should pretty quickly result in mechanical noises.

[angello]

Well.... we've got some progress...

I did as suggested - took the oil pump gear cover off, took off the oil filter, pulled all the spark plugs to reduce compression loads and spun the engine over. Good news, that gear and the pump shaft are spinning

So I went ahead and added a load more oil to the engine and span it over again.... this time, eventually, a pathetic dribble came out of the oil filter port on the block... and it really was only a dribble, certainly not enough to even overcome the resistance of the filter....

Given what you guys have recommended that really only left a broken pump as the cause....

I drained all the oil out again and stuck an endoscope through the oil drain plug hole ..... and.... it was clear to the see the bottom has broken off the oil pump

Nothing else for it but take the sump off - and this is what I found.....





On close inspection, I'm pretty sure that the pick up has actually only just snapped right off - it's clearly been fractured and cracked for a while and had been 'gaping', but not completely detached.... It looks like it was hanging on by a sliver of metal at the front which has finally given way under pressure from the oil pressure relief valve spring, whereupon it's dropped into the sump and oil pressure to the engine has dropped from 'poor' to 'none'. There was a section of the 'break' that was cleaner and fresher than the rest which looks like the last bit to have broken away....
There aren't any distressing signs of dry bearings in the sump - there's no heat discolouration visible and no notable metal shavings or bearing shell fragments in the sump or the oil I've drained out.... So I'm crossing my fingers that the engine may yet live... There definitely was oil in the cam boxes and on the cam lobes before I started these investigations, so the pump was clearly pumping some oil before the pick up came off completely.... I can only hope it was enough to have kept the bearings alive.... Only one thing for it now - new pump, whack it back together and see if we get lucky...

[Nut124]

Looks like you are making progress. Got that sump out pretty easy?

I'd consider removing a rod cap or two and inspect the bearing, journal for damage while you have access.

Odds are the pump broke while driving. It does not take long to damage the rod bearings w/o oil pressure.

[18Fiatsandcounting]

Wow, Angello, you're fast!! The pickup snout for the oil pump is a weak point in that the bottom of the snout hovers just above the bottom of the oil pan, and it snaps off if the oil pan gets dinged. Doesn't take much, and it would have been better if Fiat had used a ductile metal for this snout. But they didn't so here we are.

I remember driving in the Arizona desert in my '69 many years ago when I came across a gulley wash at the bottom of a gravel road. The front tires dropped into the gulley and the oil pan slammed into the dirt wall of the gulley. Happened too quick to stop on gravel. The engine started clattering within a few seconds after this happened, and I was pretty sure I had snapped off the oil pump snout. Fortunately, I had a gallon of oil in my trunk, so I added that and made it back to the Los Angeles area. With a new oil pump, the engine was no worse for the wear.

I'm thinking your engine is probably fine, but I agree with Nut that it wouldn't hurt to remove a couple main bearing caps and rod bearing caps and inspect the bearings. The camshafts are actually pretty robust, and you'll notice they don't even have bearings.

-Bryan

[18Fiatsandcounting]

Another thought: It's possible the previous owner whacked the oil pan, had it replaced, but didn't notice that the pump was damaged. So he/she/it put it back together and, over time, the crack in the pump grew until it finally broke off.

-Bryan