Technical Timebelt / Cambelt break

FiatSweden

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Hello. Got a problem with my Fiat Punto 1.2 16v 2001. When I drove, it stopped with all the lights on the dashboard. When checking, I see that the time belt is loose and that the teeth on the belt are gone.

Have now tried to change the timebelt / cambelt, the water pump and the tensioner. Because the old belt was not in place, problems arise. Have tried to follow various movies on change but most are when you change it and the car works.

The car refuses to start, gets a spark. Tested different variants:
1) Set all pistons at the same height and turn the camshaft with the position mark visible.
2) Set a crankshaft after marking on crankshaft and turn camshaft with position mark visible
3)Have also tried to measure compression but do not have such a small thread to the comp meter, tried with the solution without threading has no value. Want to check if the valves are tight or curved

Now need help with publishers and "step by step" solutions, preferably pictures

Best regards / Andreas
 
Joined
Feb 22, 2004
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Faringdon, Oxfordshire UK
This is not a 'safe' engine, so when the belt breaks, it is likely that pistons will hit valves. It is therefore likely that some valves are bent, so no compression on those cylinders.

Take the cam covers off and check the valve clearances. Bent ones should have large gaps. Easier than taking the head off to diagnose, but it will probably have to come off anyway.

Hopefully just some bent valves, and no damage to valve guides or pistons.
Where pistons and valves meet, the piston damage needs looking at carefully. If it is near the edge, it can compress the ring grooves, requiring new pistons. If it is just light marking, ensure there are no sharp edges to the damage points, as that can cause hot spots, otherwise, replace the bent valves, set the clearances, and enjoy a little more.
 
Joined
Jan 11, 2015
Messages
1,958
Location
Helsinki
This is not a 'safe' engine, so when the belt breaks, it is likely that pistons will hit valves. It is therefore likely that some valves are bent, so no compression on those cylinders.

Take the cam covers off and check the valve clearances. Bent ones should have large gaps. Easier than taking the head off to diagnose, but it will probably have to come off anyway.

Hopefully just some bent valves, and no damage to valve guides or pistons.
Where pistons and valves meet, the piston damage needs looking at carefully. If it is near the edge, it can compress the ring grooves, requiring new pistons. If it is just light marking, ensure there are no sharp edges to the damage points, as that can cause hot spots, otherwise, replace the bent valves, set the clearances, and enjoy a little more.
Unfortunately this engine has that head extension and I dont think there is a way to check the valves?
 
Joined
Jan 11, 2015
Messages
1,958
Location
Helsinki
Hello. Got a problem with my Fiat Punto 1.2 16v 2001. When I drove, it stopped with all the lights on the dashboard. When checking, I see that the time belt is loose and that the teeth on the belt are gone.

Have now tried to change the timebelt / cambelt, the water pump and the tensioner. Because the old belt was not in place, problems arise. Have tried to follow various movies on change but most are when you change it and the car works.

The car refuses to start, gets a spark. Tested different variants:
1) Set all pistons at the same height and turn the camshaft with the position mark visible.
2) Set a crankshaft after marking on crankshaft and turn camshaft with position mark visible
3)Have also tried to measure compression but do not have such a small thread to the comp meter, tried with the solution without threading has no value. Want to check if the valves are tight or curved

Now need help with publishers and "step by step" solutions, preferably pictures

Best regards / Andreas
You can buy a cheap Biltema compression kit with the fiat adaptors.

When you time the engine with the pistons level they can be in one of two different positions. You need the pistons level with number 1 going down for the inlet stroke rather than up for the exhaust stroke ( The pistons can be in a rising position or a descending position. So one top. one bottom and two mid way positions.
 
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