Technical Punto 55 1.1 - Camshaft end float?

Currently reading:
Technical Punto 55 1.1 - Camshaft end float?

chofy23

New member
Joined
May 12, 2018
Messages
9
Points
4
Hi everyone,

Today, after a timing belt service, I finally found the source of the "ticking" noise I was hearing for the past year, year-and-a-half.

While in there, I found out that the source of the noise was the camshaft, specifically it's (probably) excessive end float. I moved it with a screwdriver very gently, it does seem a bit excessive...

The noise only appears when the engine is warmed up, and not all the time. Sometimes i hear it, sometimes i don't.

So, my question is, does anyone have any experience with this, or what might have caused this? The car is regularly serviced, oil change every 7000 kilometres or 1 year (whichever comes first), absolutely no traces of metal shavings anywhere, no scoring on the cam lobes, everything else is in proper working order, oil pump is perfectly fine...

Since I've driven car daily with this problem for over a year, and without the noise getting worse or louder, should I prepare for a head replacement or just leave it alone? Or maybe, could a different brand of oil help? I use Selenia 10W40...

Any help or input is appreciated :)

EDIT: The camshaft noise can be heard only at idle, it immediately disappears when I apply the throttle.
 
Last edited:
FIRE family design flaw. They are prone to be noisy and have wear in unusual areas.
Doesn't matter much if you care (oil changes, valve clearances adjustment and so on).
Don't bother to experiment with oils (and/or oil additives, or fuel system cleaning and such).
Not much you can do about it. Full engine rebuild is probably best option in most cases (or at least dropping the head and real full inspection and reconditioning if necessary).
Similar issue in Grande: https://www.fiatforum.com/grande-punto/471873-injector-valve-clearance.html Not solved so far...

Probably, it can (and should) be ignored. Leave it alone and observe if it changes/escalates with time...
 
Last edited:
I have had my punto for over 5 years now and it has had the loud rattle syndrome from day one. (its so noisy it drowns out the blowing exhaust pipe):). I have been told some times the fire engine rattles but its nothing wo worry about
slayer.gif
 
Thank you everyone for your feedback.

I thought as much, since I drive the car daily to work and literally everywhere that it probably can be ignored. If it's a fairly common weird wear/design flaw, then so be it, nothing I can do about it :)

As far as the service goes, everything is done once a year as needed, no expense spared. My late grandfather was the 1st owner, and he serviced the thing regularly at a local Fiat garage, so...(y)

I'll get around to measuring the float once I obtain a dial gauge, but for now I just wanted to know if this was something fairly common or was I just unlucky.

Thank again!
 
I take it you have checked the tightness of the bolt that pulls the cam-belt pulley up against the camshaft itself. If slack the clearance will be greater than it should be.

I think the end float is controlled by the cam-belt pulley which is keyed onto the drive end of the shaft. You might try getting another from an old cylinder head in the hope there is some tolerance difference that will stack up to reduce the end play.

Or measure the play in thousandths of an inch, if you get say 0.010" then fit a bronze or brass or even steel flat thrust washer measuring say 0.008" between the pulley and the head face. But any old washer just won't do!
 
I'll get around to checking it exactly once I obtain a dial gauge. My preliminary check was basically by moving the camshaft with a screwdriver.
But interesting, I didn't know that bolt tightness affected the end float, will definitely give it a check. Thanks.
 
The pulley bolt must be tight, it may never have been tight enough (robot assembly!). I checked my 1994 Mk1 55S with its Mk2 cylinder head which I fitted, the clearance without measuring looked about 0.003" to 0.005". I doubt the camshaft is walking back and forth enough to make a clicking noise, sounds like some other problem such as a single valve clearance too wide. I would check them all with feeler gauges, turning the engine to bring each cam to the centre of the base before you measure, and write them all down. You will have to remove the camshaft to make any changes.
 
The pulley bolt must be tight, it may never have been tight enough (robot assembly!). I checked my 1994 Mk1 55S with its Mk2 cylinder head which I fitted, the clearance without measuring looked about 0.003" to 0.005". I doubt the camshaft is walking back and forth enough to make a clicking noise, sounds like some other problem such as a single valve clearance too wide. I would check them all with feeler gauges, turning the engine to bring each cam to the centre of the base before you measure, and write them all down. You will have to remove the camshaft to make any changes.
Well, that I can do actually. I do have a set of feeler gauges, I'll definitely check the clearance. To be honest, I can't even remember when it was last checked (probably about 5 years ago), so it's not a bad idea.

I presume that the camshaft making noise due to excessive float would surely result in some kind of mechanical damage inside the head. And there is literally nothing, not a single scratch anywhere. Plus, like I said, the noise did not change or increase at all, ever.

I suppose I can find the exact measurements for the valve clearance in the Haynes manual?
 
I doubt any damage is being caused by either end float in the camshaft bearings or an excessive valve clearance. But a wide clearance needs investigating as it will not have been wide when made in the factory. valves can sink into the head for several reasons, maybe there's a soft one or the head valve seat is soft for some reason. All you can do is measure the clearances and if any are out of tolerance remove the head and investigate further. One last thing to check is that oil is getting up the passage from the block and into the oil gallery that feeds the individual cams. Insufficient oil to any one cam will result in wear and noise. Remove the cam cover and clean out the feed pipe with compressed air.
 
Greetings to all from a newbie. I came across this thread while searching for a solution to my problem and I was so thrilled that someone has the same symptoms. But as I read there is no solution posted.
My parents have a Punto 55 from '97 and it has this weird sound from camshaft area at idle. Today after cleaning the engine from a previous oil leak I listened to the noise with engine running,then I slightly pressed on camshaft pulley and the noise was gone. I did dismount the cylinder head a couple of years ago due to gasket failure but the noise was there before and after work and I didn't notice any wear on camshaft or head.
I know that one of the bearing shells holds axial play and I had an idea to cut a shim from brass foil and insert it to improve the play. chofy23 did you ever find a solution?
 
OK, update...
Some people say (on non-english forums - I didn't search this particular issue in English), that this is fairly common problem in Seicento or CC models, in most (or all) 8-valve engines.
And they make, fabricate custom washers/shims to cancel out play (but not completely - it will seize!).
If I remember right, it should be something around 0,10 mm clearance. From 0,2-0,3 mm or more it will start "clicking".
Seicento_1,1_SPI.jpg

EDIT: search this forum...or just scroll the page all the way down, on suggested "Similar Threads".
Example: https://www.fiatforum.com/grande-punto/164970-end-float-camshaft-1-4-8v-vvt.html
 
Last edited:
Back
Top