General Fiat Seicento 1108 cam timing belt problem

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General Fiat Seicento 1108 cam timing belt problem

dx90

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I have fitted a new water pump, tensioner bearing and cam timing belt.

I have adjusted the cam timing belt on a Fiat Seicento 1.1 1108cc Sporting for the 16th time with the same bad results.

When the engine is cold I tension the belt so I can turn the belt 90 degrees using finger and thumb and then turn the engine over clockwise by crank twice or more and re-check timing marks and the tension is still OK

As soon as the engine gets up to temperature the cam timing belt goes too tight with the heat from the engine and starts to make a whining noise.

Is the tensioner supposed to have just a flanged nut to hold it or should it have a nut and separate washer like shown in the manual?

Is it normal for a cam timing belt to shrink with heat?

Thanks
 
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It won't shrink with heat mate :S
Have you moved the tensioner the correct way?
 
I have been using a lever bar to lever the tensioner towards the front of car and keeping the tension on it while I do up the bolt. I then turn over the engine as described above and re-check.

Is this correct?
 
I have fitted a new water pump, tensioner bearing and cam timing belt.

I have adjusted the cam timing belt on a Fiat Seicento 1.1 1108cc Sporting for the 16th time with the same bad results.

When the engine is cold I tension the belt so I can turn the belt 90 degrees using finger and thumb and then turn the engine over clockwise by crank twice or more and re-check timing marks and the tension is still OK

As soon as the engine gets up to temperature the cam timing belt goes too tight with the heat from the engine and starts to make a whining noise.

Is the tensioner supposed to have just a flanged nut to hold it or should it have a nut and separate washer like shown in the manual?

Is it normal for a cam timing belt to shrink with heat?

Thanks

Can you get a video of it doing this? I can't think what it might be...

Are you sure it's not the rad fan?
 
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There's something else going on there IMO.

The belts don't change size, think about it, if they changed size, they wouldn't fit the pulleys anymore! Also they'd start altering the timing.
 
Did you put on the auxilary belt on as well? Alternator bearings?
 
Can you get a video of it doing this? I can't think what it might be...

Are you sure it's not the rad fan?

The rad fan hasn't come on yet. Maybe the engine needs running for longer. I have no way to get a video of it at the moment.
 
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:yeahthat:

If the tensioner bearing is new, the noise is much more likely to be the alternator. Disconnect the alternator belt to be 100% sure.

Yes new tensioner bearing The noise is from the cam timing belt getting tighter as it gets hotter. I don't have the alternator belt connected.
 
I'm wondering if the belt might be faulty. Here is the kit I purchased.
http://www.ebay.co.uk/itm/371143771434?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Or if the radiator fan is not working due to the car being off road for the last year and making the engine too hot and causing the belt to go tight. What do you think?

Is there a way I can check the radiator fan with a multi meter?

The belt starts with the correct adjustment and then gets tighter as the cam timing belt gets hotter. After the engine cools down the belt is back to its correct tension again. This is not right. What can be causing this?
 
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Yes new tensioner bearing The noise is from the cam timing belt getting tighter as it gets hotter. I don't have the alternator belt connected.

The belt won't be getting tighter with heat, they don't change size.

Have you fitted the tensioner correctly?

Is anything rubbing the belt?

Are the teeth and pulleys matching? Either fat teeth or thin teeth.
 
The belt won't be getting tighter with heat, they don't change size.

Have you fitted the tensioner correctly?

Is anything rubbing the belt?

Are the teeth and pulleys matching? Either fat teeth or thin teeth.

Yes the tensioner is fitted correctly. Top hole is used to mount the tensioner and all looks the same as before I took the old one off.

I have rechecked the belt and it is centred correctly and not rubbing anywhere.

Checked old belt with new belt and both look the same.
Checked old pump with new pump and both look the same.
Checked the belt teeth are fitting into the sprockets teeth on crank, cam and water pump and all looks fine to me.

I don't understand what the problem could be.
 
Yes the tensioner is fitted correctly. Top hole is used to mount the tensioner and all looks the same as before I took the old one off.

I have rechecked the belt and it is centred correctly and not rubbing anywhere.

Checked old belt with new belt and both look the same.
Checked old pump with new pump and both look the same.
Checked the belt teeth are fitting into the sprockets teeth on crank, cam and water pump and all looks fine to me.

I don't understand what the problem could be.

Likely to not be cambelt related in that case. As mentioned, maybe the alternator.

Have you touched anything else? Is it possible it was doing this before and you didn't notice?
 
Likely to not be cambelt related in that case. As mentioned, maybe the alternator.

Have you touched anything else? Is it possible it was doing this before and you didn't notice?

As I mentioned above the Auxiliary belt to the alternator is not connected. So this eliminates the alternator.

The engine was not showing this symptom before the new cam timing belt, water pump and tensioner bearing were changed.
 
Silly thought -- if there's no oil getting to the cam bearings there may well be a lot of squeaking from there once the engine gets warm.

Head gasket on the right way round?

Stethoscope (or long screwdriver, blunt end to ear -- beware of ther belts!) will give you a clearer idea of the source of the noise.

Or pull off cam cover, check for oil flow.
 
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I have taken off and examined the tensioner bearing and the belt and all looks good. I have put the tensioner and the belt back in and adjusted the belt again. After the engine gets hot the belt goes tight again.

I was shining a touch into where the belt is when the engine was running and noticed that there were bubbles coming out from around the round blanking plug that is just below the tensioner. The engine was red hot and the radiator fan had not turned on. The car has been laid up for nearly a year.

Would an overheating engine cause the bubbles to come from around the coolant blanking plug and the extra heat from the engine expand the metal cam, crank, tensioner bearing and water pump to expand so much to cause the belt to go tight?

There is no temp gauge to check the actual temperature. What a stupid design.
 
The engine expands due to heat. Excessive heat makes it expand more. The belt will expand also. Different materials expand at different rates with reference to temperature change. The belt tension is set to allow for this at normal operating temperatures. If the fan does not come on at 90Deg/c, then there is a problem. Sort this out first.
Bubbles appearing from a blanking plug will lower the pressure and reduce the boiling point of the coolant. It also means the fluid is boiling/and/or head gasket failure.
 
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I think you have more than one issue.

Nothing should come from the core plug. Not water, not air, not bubbles.

Looks like you have a leaking core plug and air in the cooling system. At least, cold bleed the cooling system, heater full on.

I'm starting to wonder -- if you replaced the water pump -- if the water pump is the same pitch as the cam belt (there are at least 2 different pitches out there).
 
I have just disconnected the radiator fan plug and connected 12V supply direct to the fan and the fan isn't working.

Could this cause all my problems?

The new water pump I have looks the same as the old one and has the same amount of teeth if that helps.
 
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