Technical Oil Gyser wo's

cdatte

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Dec 28, 2011
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Guys,
my 72 500L was barely running, pulled off the breather hose from the aircleaner and ran great, put the hose back on and it dies.

Changed the oil filler cap and it got a little better but when I gunned the engine with the breather hose off the aircleaner oil spurts out of the hose

pulled the rocker cover off and saw that oil shoots straight up under full pressure from the tube that has the rocker shaft oil feed pipe in it. It's not squirting out of the rocker shaft.

pulled the pipe out and it was clear. Dissassembling the rocker shaft to look for any blockage today.

any thoughts about what this would be is appreciated.
 

Bambino

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Oil spurting out under pressure suggests an overpressurised sump - maybe worn rings or an overfull sump. If worn, these motors have been known to spit out the dipstick when running.

I've attached a diagram of the oil circulation in these engines.

Does it blow blue smoke when accelerating ?

Chris
 

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cdatte

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did compression test and showed ok
a little smoke but know what you mean, don't see big blue
certainly can do a leak down test
BTW what manual is that pict from ?
 

Bambino

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A leak down test would be very useful and will give you more specific information about the piston/rings/cylinder than a standard compression test.

The picture was taken from the Fiat 500 Workshop Manual.

Chris
 

babbo_umbro

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Theres a tube that runs up the side of the cylinder block - if I recall rightly inside a thin-walled tube like the ones that the pushrods sit in, which engages inside a pickup that comes off the centre of the rocker shaft - I'm dredging up memories from forty years back here so be gentle with me. Is that all assembled correctly? Also, because both the pistons go up and down together, these engines will throw out oil at the slightest opportunity - I lost the filler cap once and the engine was covered in oil within a few miles.
 

Bambino

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My only other suggestion would be to remove the dipstick while the engine is running and see if this makes a difference. In doing so, you may effectively depressurize the sump enough (if this is the problem) to make a diagnosis. You may however replace a jet of oil spurting from the rocker shaft feeder to one ejecting atomised oil from where the dipstick goes.

I started my engine last night and removed the oil filler cap - no oil spurted out. I have also run the motor with the rocker cover removed and the only oil that was spilled was due to normal low pressure splashing.

Please keep us informed on your progress, though I've got my money on worn rings.

Chris
 
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cdatte

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Dec 28, 2011
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dissassembled rocker assembly cleaned & reassembled and cleaned feed tube
still did it, does blow out of dipstick hole. compression test & leakdown today more to follow
 
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