Loose Timing Belt

The belts stretch a little when first run (this is why they should never be re-tensioned). Depending on how the engine stopped, you might feel a little slack on the belt.

I can't tell you if what you observed is okay or not.

 

Alex,

You asked a question and got a good answer from a real pro. Why would you not believe it? What else could we tell you ?

 

My thoughts, exactly

 

During an oil change, how were you able to access and or see the belts? You would have to remove the under tray and the belt covers .

 

Alex it seems that one bank will have some laxity while the other is tense. Turning crank will then reverse the dynamic. how long since last belt change?

 

My Modena has the cover. I had the under tray off on Saturday .I would have liked to see the condition of my belts .

 

You should start the car and keep it for some time then check the belt if it stell the same that's meen there is something wrong with the tensioner and you got to change it otherwise its going to do a lot of damages to the engine You don't want to know about.

 

Alex,

I had the same question 2 years ago. The belt tension really does vary based upon where the engine is in its rotation. Why does it behave this way? Tension varies because of the cam rotation and it being on the exhaust or intake position. Think of the cam lobe engaging the shim bucket and then passing its apex when it pushes the shim bucket/valve down and then rolling off of the shim bucket. Uphill vs downhill.
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Thats some interesting advise.

 

Did the tech test with the Clevis/ frequency meter or did he have any trick way to check belt tension? I am very surprised that the belt in position can have 1/2 to 3/4 push, and I do understand the different pressure at different parts of the rotation cycle

Thanks

 

I did my cam belts this past winter and had the same situation. However, I did the Ferrari procedure for setting the tension and they still had some tension play. I set the tension 2x and the situation was the same each time. So, I believe a little play in the belt on the longer spans is normal. If the tension is too tight I would think that could lead to premature failure.

 

Whats it mean

 

So interesting to me the ultrasonic meter. On my porsche 928 and 924 I used to tension it until I could just twist the belt 90 degrees. Never had any problems...

 

Last time we checked with my mechanic we came to the following conclusion :
When we opened the cambelt covers to inspect the cambelts, the driver's side cambelt was very loose...
I thought that my tensioner was bad and that I should replace it...
My mechanic explained to me that when you switch off the engine because of the momentum it slighlty rotates on the reverse direction and this causes the belts to become loose...
As soon as he rotated manually the crankshaft the belts tightened up...

Therefore, make sure that you rotate manually the crankshaft to check the correct tension of the belts !!!

 

sorry to bring this up again, if I got a tight belt (tigher than spec), is it going to
make some squeaky noise?

 

Yes, that is correct !

 

I saw your posting on the other sub forum about your timing squeak. It seems you have already ruled out belt tension as an issue with your latest frequency test. The fact that it quiets down when you spray it with water for a bit is a clue.

I suggest this: make the belts at the low end of the tension frequency spec and see if that helps you. If not, replace the belts with belts of very new date codes bought from the factory dealer.