Technical 110F Oil Pump options and low oil pressure woes

[fiat66]

Greetings all !


Its been a while since last post was made, but since i have the very same problems i take the liberty in awakening this thread.

Marcus550 - Curious if you solved your oil pressure woes ?

My 500 has a 126p engine with Panda 30 head, but how this has all been put together i have no idea as no receipts came with car (imported from Italy)
Its runs great and supposedly only have 9000 km since rebuilt.
Little blue smoke right after it fires up, but running it on idle and then throttle up no smoke.


Since it is a 126 engine i hope all the right parts are there and no mixup with 500.
Got a weird pressure sensor on it from later 4-cylinder Fiat, so hoping part of the problem lies there.
Will within next two weeks connect oil pressure measuring equipment.

Does anyone know how much pressure oil pump produces on classic 500 and 126 on idle and say 2000 rpm ?

 

[jjacob]

I believe that at 2000 rpm you should see around 40 psi (2.7 bar). I would think at idle you should see at least 15 psi (1.0 bar).
If you get blue smoke only on start up after the engine has set for awhile, that is oil leakage past the intake valves through the valve guides into the combustion chamber. Either the little oil control O-rings that fit on the intake valve stems are missing or worn, or the valve guides are worn.
John

 

[fiat66]

Hi John!
Thanks for your reply. I have barely 15 - 16 psi when i rev engine and at idle ( set to 1000 rpm ) low oil pressure light flickers.
When engine is cold i get perfekt readings.


I just hate the idea of having to tear engine apart, but driving around with 15 - 17 psi at 3000 rpm doesn´t feel so good.


i am in the progress of connecting a reliable oil pressure equipment and hopefully get a better result.

 

[fiat66]

And it should be oil pressure test equipment....


Do you know kind of thread used in oil pressure sending unit, is i M12 - 1,5 mm ?

 

[the hobbler]

According to the 'book of words', the oil pressure when the engine is idling can be (safely) as low as 8.5psi (0.6kg/sq cm)--the "low oil-pressure light will flicker at between 14psi (1 kg/sq cm) and 8.5psi when the engine is idling at below 1,000rpm---this is quite normal as long as the light goes out as soon as the engine is revved. The 500 work-shop manual does not give an oil pressure for when the engine is running above 1,000rpm, but the 126 workshop manual does. In this it states that the oil pressure should be between 35psi and 43psi (2.5 to 3.0kg/sq cm) with the engine HOT. The 126 workshop manual recommends a 15W40 multigrade oil (Duckhams Hypergrade, sadly no longer available)---a modern 20W50 is entirely suitable for a standard 500 or 126 engine. It is only necessary to go to a higher specification oil if the engine is tuned (I use Castrol 10W60 on my tuned 652cc 126 engine).

 

[fiat66]

Hi there Hobbler !

This engine is tuned for sure, but i suspect it has been driven a bit harsh.
When i first got it the carburettor had no air filter and it is not a very good idea to drive like that.
New customized air filters installed !
The big air intake hose was hanging a bit to the side back on engine. I had temperatures close to red line when i first drove it around.
Got that and now i have more normal temperatures.


Anyways if your holy book says at least 35 psi and i have 15 psi something must be done.
This is what an italian mechanic wrote to me:
We usually find that oil pressure is lost via the camshaft journal (either the cam wears or the journal in the block) also there could be wear in the main front bearing

 

[Toshi 975]

I bought a car and drove it quite hard for about 200 miles whilst I sorted out various problems with it one being the oil pressure light which I believe had been deliberately disabled. When I fixed the light I had zero oil pressure as I found out that one of the core plugs had dropped out of the crankshaft. I fixed that and replaced the big end shells in situ and the engine is still good. I guess I caught it in time. Other engines I have worked on have had various problems with oil pressure. The main bearing at the flywheel end can be a problem but also rocker shaft at the top of the engine can be very worn. Axel Gerstal were selling repair bushes for the crankcase if the camshaft journal is very worn but it required the crankcase to be bored out to take a press fit bush which in turn had to be bored to suit the camshaft. Probably easier to get a replacement crankcase. It all comes down to how well the engine has been used and maintained plus some components can fail.

 

[fiat66]

Thanks toshi,. Maybe my only option then is to dismantle engine.:bang:

 

[fiat66]

I have been told there is a way to adjust oil pressure on these engines ??
Is this an early april fool prank or what ?