Press the handle of a long handled screwdriver against your ear and put the blade on parts of the working engine that are not moving. Simple to find where the noise is coming from with that method.
Technical Punto hgt new hydraulic tappet ticking
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Technical Punto hgt new hydraulic tappet ticking
Press the handle of a long handled screwdriver against your ear and put the blade on parts of the working engine that are not moving. Simple to find where the noise is coming from with that method.
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got any data how tiny that hole is?
The hydraulic lifter is in three main parts. The large cam follower and then the two smaller parts that form the lifter that expands to create a force against the valve stem.
The filling hole in the cam follower is not so very tiny. A working assembly should pump up fine eventually and fairly quickly and will be partially emptied periodically when the lifter is compressed by the valve spring when the engine is off. So at start up it is possible for there to be some rattling that quickly goes away once the engine has been driven a little - otherwise some of the cam followers would be hammered to hell on each start up and take ages to pump up..
The problem seems to be crud that can build up on the other side of the check valve in the two smaller parts that create the lifting. There is no easy escape route for debris that passes thru the check valve, so when the engine is off the lifter can only collapse thru extremely tight tolerances which form the basis of the lifters ability to hold the valve spring pressure. The oil is not providing that ability. The lifter can only fill when it is not being compressed by a spring. Crud that is stuck on the other side of the check valve can then prevent the check valve closing so the lifter cannot pump up bit by bit before it is compressed again by the valve spring.
Either way some lifters will always be fully compressed in a well maintained engine when the engine is turned off and they must be able to be pumped back up again in a fairly short amount of time.
The big question of mine is if there's tappet gap adjustment or not supposed to be any gap at all and the lifter supposed to be tight to the camshaft all the time without a gap!
My logic tells me that no gap at all-no ticking!but the gap makes sure that the valve close until the end, so I don't know!
My logic tells me that no gap at all-no ticking!but the gap makes sure that the valve close until the end, so I don't know!
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I don't know this specific engine, but on some Fiats if you change the head gasket and fit it upside-down, you can have an oil blockage to the top of the engine.
I agree that the oil does seem very thick, I would replace it with flushing oil to clear all oilways and then fully synth 10w/40 as originally specified by Fiat.
I agree that the oil does seem very thick, I would replace it with flushing oil to clear all oilways and then fully synth 10w/40 as originally specified by Fiat.
That's a good call. The 8v is prone to this, it is likely the block of the 16v is similar, so also possible.
When the valve seals and lifters were replaced, was the head gasket replaced also?
On the 8V petrol there is a rectangular tab sticking out just about where the dipstick is at the rear (inlet) side of the block, timing belt side.
No, a blockage on the pressure side will not put the oil pressure warning light on. The light comes on with low pressure. A blockage will increase the oil pressure or the flow through the pressure relief valve. If just the head oilways are blocked it would not make much difference to the pressure, most of the oil flow is through the lower parts of the engine.
Robert G8RPI.
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Putting the headgasket on wrong will not have any effect on the oil pressure warning light.
If the head gasket is on wrong there is no oil flow to the lifters. The lifters are at the top of the engine. The oil pressure switch is at the bottom of the engine. The oil pressure light goes off if there is some oil pressure.
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