Aux Belt Tensioner Proper Fix!

This is a common problem on Bravo, Brava, Marea JTD engines in particular.
Carried out successful repair yesterday on Auxillary-belt
If you have any of these symptoms on start-up or idling;

a rotating whiney noise adjacent to alternator.
flapping belt
metallic pinging

This is cause...the aux-belt self adjusting tensioner spring is weak and pulley bearing attached to is is likely worn. to fix you need a large ring spanner and some energy to turn the nut on the tensioner wheel anti-clockwise to release the tension.
You then get serpentine belt out the way and and undo the tensioner retaining M8 nut. remove tensioner and replace with new-one (£32) trade from fiat and job fixed!! I didnt need a belt but should the belt hace cracks in or look tired replace that too (£16) fiat.
All quiet now! it sounds like a proper diesel, just that little tensioner can cause such a racket when worn or loose. Should point out that if it had failed the belt will fly off and shred things. It also drives the power steering pulley so your steering would be heavy and possibly dangerous if driving a speeds!!

Hope this article helps you fiat owners!

hi,

yeap..it is a common problem for JTD. mine had the similar problem 2 yrs ago when i got it and immediately change the tensioner. it helps a lot on reducing pinging noise but the tensioner was still moving back n fore rapidly in about 8-10mm displacement. at that time, i am still not satisfy with tensioner. with that kind of vibration, very soon the spring will goes weak.

i did checked my crack pulley for damage and can't find any problem and hav to settle with that condition for 1+ year.

recently, the noise getting bad again and decided to take a look again. the tensioner was badly worn out and slanting after about 40K km only. i think something still not right. make me no choice and decided to change a new tensioner and crank pulley.

wa lar....! the engine idles much quieter and not more flapping at all. the best part is the tensioner hardly vibrate ..maybe 2-3mm which is normal for many cars. no more belt slipping sounds and engine vibration is lesser. not my JTD idling with a proper tune...and no longer shame to take it to the crowd...

Just to make you feel better, I have a JTD130 Marea. The access to the alternator belt is dreadful, you have to undo a mount and lower the engine to remove the tensioner and a (cheap) new tensioner is £130.00.

Enjoy

Ian